End cap assembly, battery cell, battery, and electric device

Abstract

This application provides an end cap assembly, a battery cell, a battery, and an electrical device, belonging to the field of battery technology. The end cap assembly includes an end cap and a pressure relief component. The pressure relief component is disposed on the end cap and has a groove. The pressure relief component is configured to crack along the groove when the internal pressure or temperature of the battery cell reaches a threshold, thereby releasing the internal pressure of the battery cell. The hardness of the pressure relief component is less than that of the end cap. This structure facilitates the machining of the groove on the pressure relief component, ensuring machining accuracy and eliminating the need for excessive groove depth. This allows for an increase in the wall thickness of the groove bottom, improving the deformation resistance of the pressure relief component. Consequently, it reduces the likelihood of deformation of the groove bottom wall under external forces, thus minimizing impact resistance and ensuring stable pressure relief, thereby reducing the risk of battery cell fire and explosion during use.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to an end cap assembly, a battery cell, a battery, and an electrical device. Background Technology

[0002] Lithium-ion batteries possess outstanding advantages such as high energy density, low environmental pollution, high power density, long lifespan, wide applicability, and low self-discharge coefficient, making them one of the most widely used batteries in the world and a crucial component of new energy development. With the continuous development of lithium-ion battery technology, higher requirements have been placed on their safety performance. Among these, the pressure relief components on lithium-ion batteries have a significant impact on their safety. However, when a lithium-ion battery experiences a short circuit or overcharging, it is highly susceptible to internal thermal runaway, leading to a sudden increase in internal pressure and posing a significant safety hazard. Summary of the Invention

[0003] This application provides an end cap assembly, a battery cell, a battery, and an electrical device, which can effectively reduce safety hazards during battery use.

[0004] In a first aspect, embodiments of this application provide an end cap assembly for a battery cell. The end cap assembly includes an end cap and a pressure relief component. The pressure relief component is disposed on the end cap and has a groove. The pressure relief component is configured to crack along the groove when the internal pressure or temperature of the battery cell reaches a threshold, so as to release the internal pressure of the battery cell. The hardness of the pressure relief component is less than the hardness of the end cap.

[0005] In the above technical solution, the end cap assembly is equipped with a pressure relief component for releasing the internal pressure of the battery cell. By setting the hardness of the pressure relief component to be less than that of the end cap, this structure facilitates the machining of grooves on the pressure relief component, ensuring the machining accuracy of the grooves. This allows the pressure relief component to crack along the grooves when the internal pressure or temperature of the battery cell reaches a threshold, releasing the internal pressure of the battery cell and reducing the risk of fire and explosion during battery cell use. On the other hand, while ensuring the hardness of the end cap, the internal gas of the battery cell can easily push open the grooves of the pressure relief component without machining the grooves too deep. This increases the wall thickness of the groove bottom, improving the deformation resistance of the pressure relief component. This effectively reduces the phenomenon of deformation of the groove bottom wall under external force, which would reduce the impact resistance of the pressure relief component. As a result, the pressure relief component can only crack along the grooves when the internal pressure or temperature of the battery cell reaches a threshold, ensuring stable pressure relief. In addition, since the hardness of the end cap is greater than that of the pressure relief component, when the internal pressure of the battery cell increases, the internal gas of the battery cell will preferentially cause the pressure relief component with lower hardness to crack, so that the pressure relief component can play the function of relieving pressure, thereby making it easier to control the exhaust direction of the battery cell.

[0006] In some embodiments, the melting point of the pressure relief element is lower than that of the end cap.

[0007] In the above technical solution, by setting the melting point of the end cap to be higher than that of the pressure relief component, the end cap can withstand higher temperatures than the pressure relief component when thermal runaway occurs inside the battery cell. This can effectively reduce the premature melting of the end cap, so that the internal gas of the battery cell can be stably released through the pressure relief component, thereby effectively reducing the risk of fire and explosion of the battery cell.

[0008] In some embodiments, the end cap has a melting point above 1000 degrees Celsius.

[0009] In the above technical solution, by setting the melting point of the end cap to above 1000 degrees Celsius, the end cap can withstand most high-temperature environments during use, thereby effectively reducing the phenomenon of premature melting of the end cap and improving the safety of battery cells.

[0010] In some embodiments, the end cap is made of steel.

[0011] In the above technical solution, the end cap made of steel has high hardness and melting point, which helps to improve the structural strength and high-temperature resistance of the end cap, thereby effectively reducing the phenomenon of premature melting of the end cap and achieving a better explosion-proof effect. In addition, the end cap made of this material is low in cost and easy to process and manufacture.

[0012] In some embodiments, the pressure relief element is made of aluminum.

[0013] In the above technical solution, using aluminum, a material with lower hardness, makes it easier to machine grooves on the pressure relief component, resulting in lower cost. It also allows the internal gas of the battery cell to more easily break through the pressure relief component, thereby achieving a better pressure relief effect.

[0014] In some embodiments, the end cap assembly further includes a connector and a limiting member; the connector is connected to the end cap, the connector is provided with a pressure relief hole for communicating with the interior of the battery cell, and the pressure relief member covers the pressure relief hole; the limiting member is connected to the connector, and in the thickness direction of the end cap, the limiting member and the connector are used to clamp a portion of the pressure relief member.

[0015] In the above technical solution, the end cap assembly is provided with a connector and a limiting member. The connector is connected to the end cap. By connecting the limiting member to the connector, the limiting member and the connector can cooperate to clamp the pressure relief member. This structure enables the pressure relief member to be installed on the end cap, which is made of a different material. The connector is provided with a pressure relief hole that communicates with the inside of the battery cell. The pressure relief member covers the pressure relief hole so that the pressure relief member can meet the pressure relief requirements of the battery cell.

[0016] In some embodiments, the connector includes a first connecting portion and a second connecting portion; the first connecting portion is connected to the end cap, and the pressure relief hole is disposed in the first connecting portion; the second connecting portion surrounds the edge of the first connecting portion; the limiting member and the pressure relief member are both located on the inner peripheral side of the second connecting portion, and the limiting member is connected to the second connecting portion. In the thickness direction of the end cap, the limiting member and the portion of the first connecting portion are used to clamp the pressure relief member.

[0017] In the above technical solution, by setting the connector into two parts, a first connecting part and a second connecting part, the first connecting part is connected to the end cap, and the second connecting part surrounds the outside of the first connecting part, so that the limiting part and the pressure relief part can be set on the inner circumference of the second connecting part. After the limiting part is connected to the second connecting part, the limiting part can cooperate with the first connecting part to clamp the pressure relief part, so as to fix the pressure relief part. The connector with this structure is beneficial to improving the structural stability of the end cap assembly and facilitates the assembly of the end cap assembly.

[0018] In some embodiments, the end cap is provided with a positioning hole penetrating its inner and outer surfaces; at least a portion of the first connecting portion is inserted into the positioning hole.

[0019] In the above technical solution, by providing a positioning hole on the end cap, at least part of the first connecting part can be inserted into the positioning hole to position and limit the connecting part, thereby improving the installation accuracy between the connecting part and the end cap.

[0020] In some embodiments, the limiting member is an annular structure extending circumferentially along the pressure relief member.

[0021] In the above technical solution, by setting the limiting member as a ring structure extending circumferentially along the pressure relief member, the limiting member can cooperate with the connecting member to clamp the pressure relief member circumferentially, thereby improving the stability of the pressure relief member installed on the end cover.

[0022] In some embodiments, the limiting member is located on the outer periphery of the groove.

[0023] In the above technical solution, by setting the limiting member on the outer periphery of the groove of the pressure relief member, that is, when the limiting member and the connecting member cooperate to clamp the pressure relief member, the limiting member can effectively avoid the location of the groove of the pressure relief member, thereby effectively mitigating the impact of the limiting member on the pressure relief member needing to crack along the groove when the internal pressure or temperature of the battery cell reaches the threshold.

[0024] In some embodiments, the connector is made of the same material as the end cap, and the connector is welded to the end cap.

[0025] In the above technical solution, by setting the material of the connector to be the same as that of the end cap, the connector can be welded to the end cap, thereby effectively improving the connection strength between the connector and the end cap, which in turn helps to improve the structural strength of the end cap assembly.

[0026] In some embodiments, the limiting member is made of the same material as the connecting member, and the limiting member is welded to the connecting member.

[0027] In the above technical solution, by setting the material of the limiting component to be the same as that of the connecting component, the limiting component can be welded to the connecting component, thereby effectively improving the connection strength between the limiting component and the connecting component, which in turn helps to improve the structural strength of the end cap assembly.

[0028] In some embodiments, the end cap assembly further includes a seal; at least a portion of the seal is located between the connector and the pressure relief member in the thickness direction of the end cap, the seal being used to seal the connector and the pressure relief member.

[0029] In the above technical solution, by setting a seal between the connector and the pressure relief component, the seal can seal the gap between the connector and the pressure relief component, thereby reducing the leakage of internal gas from the battery cell through the gap between the connector and the pressure relief component, reducing the failure of the pressure relief component, and thus improving the safety of the battery cell with this end cap assembly.

[0030] In some embodiments, in the thickness direction of the end cap, the connector has a contact surface for the seal to abut against; a limiting protrusion is provided on the contact surface, the limiting protrusion being an annular structure extending circumferentially along the pressure relief hole, and the seal is sleeved on the outer peripheral surface of the limiting protrusion.

[0031] In the above technical solution, the connector is provided with a mating surface for the sealing element to abut against, so that the sealing element is located between the mating surface and the pressure relief element. The mating surface is provided with a limiting protrusion extending circumferentially along the pressure relief hole. By fitting the sealing element onto the outer circumferential surface of the limiting protrusion, the limiting protrusion can play a certain limiting role on the sealing element, thereby restricting the phenomenon of the sealing element moving between the connector and the pressure relief element, and thus improving the sealing effect of the sealing element on the connector and the pressure relief element.

[0032] In some embodiments, the end cap assembly further includes an insulating element; in the thickness direction of the end cap, at least a portion of the insulating element is located between the pressure relief element and the limiting element to provide insulation between the pressure relief element and the limiting element.

[0033] In the above technical solution, the end cap assembly is also provided with an insulating component, and at least a portion of the insulating component is disposed between the pressure relief component and the limiting component to achieve insulation isolation between the pressure relief component and the limiting component. In other words, the insulating component can achieve electrical insulation between the pressure relief component and the limiting component, reducing the phenomenon of current conduction between the pressure relief component and the limiting component, thereby improving the service life of the pressure relief component and the safety of the battery cell with this end cap assembly.

[0034] In some embodiments, the insulating member includes a first insulator; in the thickness direction of the end cap, the limiting member is provided with a first limiting groove on the side facing the pressure relief member, the first limiting groove being used to accommodate at least a portion of the first insulator to restrict the movement of the insulating member along a preset direction, the preset direction being perpendicular to the thickness direction of the end cap.

[0035] In the above technical solution, by providing a first limiting groove on the side of the limiting member facing the pressure relief member, at least a portion of the first insulator of the insulating member can be accommodated in the first limiting groove, thereby effectively restricting the movement of the insulating member along a preset direction perpendicular to the thickness direction of the end cover, reducing the phenomenon of the insulating member detaching from the pressure relief member and the limiting member, and thus improving the insulating isolation effect of the insulating member on the pressure relief member and the limiting member.

[0036] In some embodiments, in the thickness direction of the end cap, a second limiting groove is provided on the side of the first insulator facing the pressure relief member, the second limiting groove being used to accommodate a portion of the pressure relief member to restrict the pressure relief member from moving along the preset direction.

[0037] In the above technical solution, by setting a second limiting groove on the side of the first insulator facing the pressure relief component, the second limiting groove can accommodate part of the pressure relief component. This effectively restricts the movement of the pressure relief component in a preset direction when the internal gas of the battery cell arches the pressure relief component, thereby reducing the phenomenon of large gaps between the pressure relief component and the connecting component due to misalignment. This is beneficial to improving the installation stability of the pressure relief component and reducing the phenomenon of leakage of internal gas of the battery cell.

[0038] In some embodiments, the insulating member further includes a second insulator, which protrudes from the inner peripheral surface of the first insulator and is located between the limiting member and the pressure relief member in the thickness direction of the end cap.

[0039] In the above technical solution, the insulating component is further provided with a second insulator. By protruding the second insulator on the inner circumferential surface of the first insulator and placing the second insulator between the limiting component and the pressure relief component in the thickness direction of the end cap, the pressure relief component is separated from the groove sidewall of the first limiting groove, thereby improving the insulating effect of the insulating component on the pressure relief component and the limiting component.

[0040] In some embodiments, in the thickness direction of the end cap, a first limiting groove is provided on the side of the limiting member facing the pressure relief member. The first limiting groove is used to accommodate a portion of the pressure relief member to restrict the pressure relief member from moving along a preset direction, which is perpendicular to the thickness direction of the end cap.

[0041] In the above technical solution, by setting a first limiting groove on the side of the limiting member facing the pressure relief member, the first limiting groove can accommodate part of the pressure relief member. This effectively restricts the movement of the pressure relief member in a preset direction when the internal gas of the battery cell arches the pressure relief member, thereby reducing the phenomenon of large gaps between the pressure relief member and the connecting member due to misalignment. This is beneficial to improving the installation stability of the pressure relief member and reducing the phenomenon of leakage of internal gas of the battery cell.

[0042] In some embodiments, the pressure relief component includes a pressure relief portion and a fixing portion; the pressure relief portion is provided with the groove, and the pressure relief portion is configured to crack along the groove when the internal pressure or temperature of the battery cell reaches a threshold, so as to release the internal pressure of the battery cell; the fixing portion is located on the outer periphery of the pressure relief portion along the preset direction, and at least a portion of the fixing portion is accommodated in the first limiting groove; in the thickness direction of the end cap, the outer surface of the fixing portion is closer to the outside of the battery cell than the outer surface of the pressure relief portion, and a stepped surface is formed between the outer surface of the fixing portion and the outer surface of the pressure relief portion.

[0043] In the above technical solution, the pressure relief component is provided with two parts: a pressure relief part and a fixing part. A groove is provided on the pressure relief part so that the pressure relief part can play a pressure relief role when the internal pressure or temperature of the battery cell reaches a threshold. By providing the fixing part on the outer periphery of the pressure relief part, and the outer surface of the fixing part being further away from the interior of the battery cell than the outer surface of the pressure relief part, a stepped surface is formed between the fixing part and the pressure relief part. Thus, after at least a part of the fixing part is accommodated in the first limiting groove of the limiting component, the stepped surface between the fixing part and the pressure relief part can be abutted by the groove sidewall of the first limiting groove. In this way, the first limiting groove can limit the pressure relief component. The structure is simple and has high stability.

[0044] In some embodiments, the limiting member includes a body portion, a first limiting portion, and a second limiting portion; the body portion is connected to the connector, and in the thickness direction of the end cap, the body portion is used to press against the fixing portion; the first limiting portion and the second limiting portion protrude from the side of the body portion facing the pressure relief member; the first limiting portion and the second limiting portion are both annular structures extending circumferentially along the pressure relief hole; the second limiting portion is located inside the first limiting portion; the second limiting portion, the body portion, and the first limiting portion together define the first limiting groove; the end cap assembly further includes an insulating member, and in the thickness direction of the end cap, at least a portion of the insulating member is located between the fixing portion and the body portion to insulate the pressure relief member and the limiting member.

[0045] In the above technical solution, the limiting member includes a body portion, a first limiting portion, and a second limiting portion. The body portion is used to press against the fixing portion of the pressure relief member, so that the body portion can cooperate with the connecting member to clamp the pressure relief member. By having both the first and second limiting portions protrude from the side of the body portion facing the pressure relief member, and by placing the second limiting portion inside the first limiting portion, the second limiting portion and the first limiting portion are arranged at intervals in a predetermined direction. This allows the second limiting portion, the body portion, and the first limiting portion to jointly define a first limiting groove for accommodating the fixing portion of the pressure relief member. Furthermore, by providing an insulating member between the fixing portion and the body portion, insulation isolation is achieved between the pressure relief member and the limiting member. In other words, the insulating member enables electrical insulation between the pressure relief member and the limiting member, reducing the phenomenon of current conduction between the pressure relief member and the limiting member, thereby reducing the safety hazards of battery cells with this end cap assembly.

[0046] In some embodiments, the insulating member includes a first insulator, the first insulator including a first insulating portion, a second insulating portion, and a third insulating portion; the second insulating portion is received within the first limiting groove, and in the thickness direction of the end cap, the first insulating portion and the third insulating portion protrude from the side of the second insulating portion facing the pressure relief member, the first insulating portion and the third insulating portion are both annular structures extending circumferentially along the pressure relief hole, the third insulating portion is located inside the first insulating portion, the first insulating portion, the second insulating portion and the third insulating portion together define a second limiting groove, the second limiting groove is used to receive a portion of the fixing portion to restrict the pressure relief member from moving along the preset direction; the first insulating portion is at least partially located between the inner peripheral surface of the first limiting portion and the outer peripheral surface of the pressure relief member; and / or the third insulating portion is at least partially located between the outer peripheral surface of the second limiting portion and the stepped surface.

[0047] In the above technical solution, the first insulator is provided with a first insulating part, a second insulating part, and a third insulating part. By accommodating the second insulating part within the first limiting groove of the limiting member, and by having the first and third insulating parts protrude from the side of the second insulating part facing the pressure relief member, the first, second, and third insulating parts define a second limiting groove for accommodating the fixing part of the pressure relief member. Thus, while the limiting member restricts the movement of the insulating member in a preset direction, the limiting member can indirectly restrict the movement of the pressure relief member in the preset direction through the insulating member, and can also effectively ensure insulation isolation between the limiting member and the pressure relief member. Furthermore, by disposing at least a portion of the first insulating part between the inner circumferential surface of the first limiting member and the outer circumferential surface of the pressure relief member, insulation isolation between the first limiting member and the pressure relief member can be achieved. Similarly, by disposing at least a portion of the third insulating part between the outer circumferential surface of the second limiting member and the stepped surface of the pressure relief member, insulation isolation between the second limiting member and the pressure relief member can be achieved.

[0048] In some embodiments, the insulating member further includes a second insulator connected to the third insulating portion, the second insulator protruding from the inner peripheral surface of the third insulating portion and located between the second limiting portion and the pressure relief portion in the thickness direction of the end cap.

[0049] In the above technical solution, the insulating component is further provided with a second insulator connected to the third insulating part. By protruding the second insulator on the inner circumferential surface of the third insulating part and placing the second insulator between the second limiting part of the limiting component and the pressure relief part of the pressure relief component in the thickness direction of the end cap, the pressure relief part of the pressure relief component and the second limiting part of the limiting component are separated, thereby improving the insulating effect of the insulating component on the pressure relief component and the limiting component.

[0050] Secondly, embodiments of this application also provide a battery cell, including an electrode assembly, a housing, and the aforementioned end cap assembly; the housing has an opening for accommodating the electrode assembly; and the end cap is used to cover the opening.

[0051] In some embodiments, the material of the housing is the same as that of the end cap, and the housing is welded to the end cap.

[0052] In the above technical solution, by setting the material of the shell to be the same as that of the end cap, the battery cell with this structure can achieve welding between the shell and the end cap, thereby effectively providing the connection strength between the shell and the end cap assembly. On the other hand, since the shell material is the same as the end cap material, the hardness of the shell is greater than that of the pressure relief component, which helps to improve the impact resistance of the shell. When the internal pressure of the battery cell increases, the internal gas of the battery cell will preferentially impact the pressure relief component with lower hardness to achieve stable pressure relief, thereby helping to reduce the safety hazards of the battery cell.

[0053] Thirdly, embodiments of this application also provide a battery, including a housing and the aforementioned battery cell; the housing is used to house the battery cell.

[0054] Fourthly, embodiments of this application also provide an electrical device, including the battery described above.

[0055] Fifthly, embodiments of this application also provide a method for manufacturing an end cap assembly, comprising:

[0056] End caps are provided;

[0057] A pressure relief component is provided, the pressure relief component having a groove, the pressure relief component being configured to crack along the groove when the internal pressure or temperature of the battery cell reaches a threshold, so as to release the internal pressure of the battery cell;

[0058] Install the pressure relief component onto the end cap;

[0059] The hardness of the pressure relief component is less than that of the end cap.

[0060] Sixthly, embodiments of this application also provide a manufacturing apparatus for an end cap assembly, including a first providing device, a second providing device, and an assembly device; the first providing device is used to provide an end cap; the second providing device is used to provide a pressure relief member, the pressure relief member having a groove, the pressure relief member being configured to crack along the groove when the internal pressure or temperature of a battery cell reaches a threshold, so as to release the internal pressure of the battery cell; the assembly device is used to install the pressure relief member onto the end cap; wherein, the hardness of the pressure relief member is less than the hardness of the end cap. Attached Figure Description

[0061] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0062] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0063] Figure 2 Exploded views of the battery structure provided in some embodiments of this application;

[0064] Figure 3 Exploded views of the structure of a single battery cell provided in some embodiments of this application;

[0065] Figure 4 This is a schematic diagram of the structure of the end cap assembly provided in some embodiments of this application;

[0066] Figure 5 Exploded views of the end cap assembly provided in some embodiments of this application;

[0067] Figure 6 A cross-sectional view of an end cap assembly provided in some embodiments of this application;

[0068] Figure 7 for Figure 6 A partial enlarged view of point A of the end cap assembly shown;

[0069] Figure 8 A cross-sectional view of a limiting member provided in some embodiments of this application;

[0070] Figure 9 Cross-sectional views of insulating elements provided in some embodiments of this application;

[0071] Figure 10 This is a schematic diagram of the structure of a pressure relief component provided in some embodiments of this application;

[0072] Figure 11 A cross-sectional view of a pressure relief component provided in some embodiments of this application;

[0073] Figure 12 A cross-sectional view of an end cap assembly provided in some embodiments of this application;

[0074] Figure 13 for Figure 12 A partial enlarged view of point B of the end cap assembly shown;

[0075] Figure 14 This is a schematic flowchart illustrating a method for manufacturing an end cap assembly according to some embodiments of this application;

[0076] Figure 15 A schematic block diagram of a manufacturing apparatus for an end cap assembly provided in some embodiments of this application.

[0077] Icons: 1000 - Vehicle; 100 - Battery; 10 - Housing; 11 - First Part; 12 - Second Part; 20 - Battery Cell; 21 - Electrode Assembly; 22 - Housing; 221 - Sealed Space; 23 - End Cap Assembly; 231 - End Cap; 2311 - Positioning Hole; 232 - Pressure Relief Component; 2321 - Score Groove; 2322 - Pressure Relief Section; 2323 - Fixing Section; 2324 - Stepped Surface; 233 - Positive Electrode Terminal; 234 - Negative Electrode Terminal; 235 - Connector; 2351 - Pressure Relief Hole; 2352 - First Connecting Section; 2353 - Second Connecting Section; 2354 - Abutting Surface; 2 355 - Limiting protrusion; 236 - Limiting element; 2361 - First limiting groove; 2362 - Body part; 2363 - First limiting part; 2364 - Second limiting part; 237 - Sealing element; 238 - Insulating element; 2381 - First insulator; 2381a - Second limiting groove; 2381b - First insulating part; 2381c - Second insulating part; 2381d - Third insulating part; 2382 - Second insulator; 200 - Controller; 300 - Motor; 2000 - Manufacturing equipment; 2100 - First supplying device; 2200 - Second supplying device; 2300 - Assembly device; X - Preset direction. Detailed Implementation

[0078] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0079] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0080] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0081] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0082] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0083] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0084] In this application, "multiple" means two or more (including two).

[0085] In this application, the battery cell may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, etc., and the embodiments of this application are not limited to these. The battery cell may be cylindrical, flat, cuboid, or other shapes, etc., and the embodiments of this application are not limited to these. Battery cells are generally divided into three types according to their packaging method: cylindrical battery cells, square battery cells, and pouch battery cells, and the embodiments of this application are not limited to these.

[0086] The battery mentioned in the embodiments of this application refers to a single physical module comprising one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in this application may include a battery module or a battery pack. A battery generally includes a housing for encapsulating one or more battery cells. The housing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0087] A battery cell includes an electrode assembly and an electrolyte. The electrode assembly consists of a positive electrode, a negative electrode, and a separator. The battery cell primarily functions by the movement of metal ions between the positive and negative electrodes. The positive electrode includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector, and the uncoated positive current collector protrudes beyond the coated one, serving as the positive electrode tab. Taking a lithium-ion battery as an example, the positive current collector can be made of aluminum, and the positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode includes a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative current collector, and the uncoated negative current collector protrudes beyond the coated one, serving as the negative electrode tab. The negative electrode current collector can be made of copper, and the negative electrode active material can be carbon or silicon, etc. To ensure that a large current can be passed without melting, there are multiple positive electrode tabs stacked together, and there are multiple negative electrode tabs stacked together.

[0088] The separator can be made of PP (polypropylene) or PE (polyethylene), etc. Furthermore, the electrode assembly can be a wound structure or a stacked structure; the embodiments of this application are not limited to these.

[0089] Lithium-ion batteries possess outstanding advantages such as high energy density, low environmental pollution, high power density, long lifespan, wide applicability, and low self-discharge coefficient, making them one of the most widely used batteries in the world today and a crucial component of new energy development. With the continuous development of lithium-ion battery technology, higher requirements have been placed on the safety performance of lithium-ion batteries. Among these, the pressure relief components on lithium-ion batteries have a significant impact on their safety performance. When the internal gas pressure of a lithium-ion battery suddenly increases, the end cap assembly needs to be actuated to release the internal gas pressure outward, thereby preventing the lithium-ion battery from exploding.

[0090] The inventors discovered that when lithium-ion batteries experience short circuits or overcharging, they are highly susceptible to internal thermal runaway, leading to a sudden increase in internal pressure and posing safety hazards such as fire and explosion. In existing technologies, to reduce the risk of battery explosion, aluminum casings and end caps are typically used, with aluminum pressure relief components welded to the end caps. This allows the internal pressure in a single battery cell to rupture through the pressure relief component during thermal runaway, releasing the internal pressure and reducing the risk of fire and explosion. However, aluminum casings and end caps cannot withstand high temperatures and are prone to premature melting in high-temperature environments, which can easily cause battery fires and explosions. To address this, existing technologies typically use steel casings with higher hardness to mitigate the melting problem at high temperatures. Pressure relief components with grooves are also incorporated into the steel casings to facilitate pressure relief. However, due to the high hardness of steel casings and the fact that pressure relief grooves are usually formed directly by stamping on the steel, it is difficult to guarantee the machining accuracy of the grooves. Consequently, when the internal pressure or temperature of a battery cell reaches a threshold, the pressure relief component may not be able to crack along the grooves and release the internal pressure of the battery cell. This can lead to a risk of battery cells catching fire and exploding, posing a significant safety hazard during use.

[0091] Based on the above considerations, in order to solve the problem of significant safety hazards in the use of individual battery cells, the inventors, after in-depth research, designed an end cap assembly. The end cap is equipped with a pressure relief component, which has a groove. The pressure relief component is used to crack along the groove when the internal pressure or temperature of the individual battery cell reaches a threshold, so as to release the internal pressure of the individual battery cell. The material hardness of the pressure relief component is set to be less than that of the end cap.

[0092] This type of end cap assembly is used in battery cells. The end cap of the end cap assembly is equipped with a pressure relief component for releasing the internal pressure of the battery cell. By setting the hardness of the pressure relief component to be less than that of the end cap, it is easier to machine grooves on the pressure relief component. This helps to ensure the machining accuracy of the grooves, so that when the internal pressure or temperature of the battery cell reaches a threshold, the pressure relief component can crack along the grooves and release the internal pressure of the battery cell, thereby reducing the safety hazards such as fire and explosion that may easily occur in the battery cell during use.

[0093] In practical use, by setting the hardness of the pressure relief component to be less than that of the end cap, the internal gas of the battery cell can be blasted open by the groove of the pressure relief component while ensuring the hardness of the end cap. This eliminates the need to process the groove too deeply, thereby increasing the wall thickness of the groove bottom and improving the deformation resistance of the pressure relief component. This effectively reduces the phenomenon of deformation of the pressure relief component under external force, which would otherwise reduce its impact resistance. As a result, the pressure relief component can crack along the groove in time when the internal pressure or temperature of the battery cell reaches the threshold.

[0094] In addition, since the hardness of the end cap is greater than that of the pressure relief component, when the internal pressure of the battery cell increases, the internal gas of the battery cell will preferentially impact the pressure relief component with lower hardness, so that the pressure relief component can perform the function of pressure relief, which is conducive to making the exhaust direction of the battery cell controllable.

[0095] The end cap assembly disclosed in this application can be used, but is not limited to, in electrical devices such as vehicles, ships, or aircraft. A power system for such an electrical device can be composed of the end cap assembly disclosed in this application, a battery, etc., which helps to mitigate the risks of battery fires and explosions, thereby improving battery lifespan and safety.

[0096] This application provides an electrical device that uses a battery as a power source. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, 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.

[0097] For ease of explanation, the following embodiments will be described using a vehicle 1000 as an example of an electrical device according to an embodiment of this application.

[0098] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of this application. The 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 disposed inside the vehicle 1000, and the battery 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery 100 can be used to power the vehicle 1000; for example, the battery 100 can serve as the operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to supply power to the motor 300, for example, to meet the power needs of the vehicle 1000 during startup, navigation, and driving.

[0099] 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.

[0100] Please refer to Figure 2 , Figure 2 This is an exploded view of the structure of a battery 100 provided in some embodiments of this application. The battery 100 includes a housing 10 and a battery cell 20, with the housing 10 used to house the battery cell 20. The housing 10 provides a space for housing the battery cell 20, and can adopt various structures. In some embodiments, the housing 10 may include a first portion 11 and a second portion 12, which overlap each other, jointly defining a space for housing the battery cell 20. The second portion 12 may be a hollow structure with one open end, and the first portion 11 may be a plate-like structure, covering the open side of the second portion 12 so that the first portion 11 and the second portion 12 jointly define the space; alternatively, the first portion 11 and the second portion 12 may both be hollow structures with one open side, with the open side of the first portion 11 covering the open side of the second portion 12. Of course, the housing 10 formed by the first portion 11 and the second portion 12 can be of various shapes, such as a cylinder, a cuboid, etc.

[0101] In battery 100, there can be multiple battery cells 20, which can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 20 are connected in both series and parallel configurations. Multiple battery cells 20 can be directly connected in series, parallel, or in a mixed manner, and then the entire assembly of the multiple battery cells 20 is housed within the housing 10. Alternatively, battery 100 can also be composed of multiple battery cells 20 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 also housed within the housing 10. Battery 100 may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 20.

[0102] Each battery cell 20 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. The battery cell 20 can be cylindrical, flat, cuboid, or other shapes.

[0103] Please refer to Figure 3 , Figure 3The following is an exploded view of the structure of a battery cell 20 provided in some embodiments of this application. The battery cell 20 includes an electrode assembly 21, a housing 22, and an end cap assembly 23. The housing 22 has an opening for accommodating the electrode assembly 21, and the end cap assembly 23 is used to close the opening of the housing 22.

[0104] Electrode assembly 21 is a component in the battery cell 20 where electrochemical reactions occur. Electrode assembly 21 may include a positive electrode, a negative electrode, and a separator. Electrode assembly 21 can be a wound structure formed by winding the positive electrode, separator, and negative electrode, or a stacked structure formed by arranging the positive electrode, separator, and negative electrode in layers. For example, in… Figure 3 In the middle, the electrode assembly 21 is a wound structure formed by winding a positive electrode sheet, a separator and a negative electrode sheet.

[0105] The shell 22 can also be used to contain electrolytes, such as electrolyte solutions. The shell 22 can have various structural forms.

[0106] In some embodiments, the housing 22 is a hollow structure with an opening on one side, and the end cap assembly 23 covers the opening of the housing 22 and forms a sealed connection to form a sealed space 221 for accommodating the electrode assembly 21 and the electrolyte. When assembling the battery cell 20, the electrode assembly 21 can be placed into the housing 22 first, and the electrolyte can be filled into the housing 22. Then, the end cap assembly 23 can be covered by the opening of the housing 22.

[0107] The housing 22 can have various shapes, such as a cylinder or a cuboid. The shape of the housing 22 can be determined based on the specific shape of the electrode assembly 21. For example, if the electrode assembly 21 is a cylindrical structure, a cylindrical housing can be used; if the electrode assembly 21 is a cuboid structure, a cuboid housing can be used. Of course, the end cap assembly 23 can also have various structures. The shape of the end cap assembly 23 can be adapted to the shape of the housing 22; for example, the end cap assembly 23 can be a plate-like structure, a hollow structure with one open end, etc. For example, in… Figure 3 In the middle, the shell 22 has a cuboid structure, and the end cap assembly 23 has a plate-like structure, which covers the opening of the shell 22.

[0108] Understandably, the battery cell 20 is not limited to the structure described above. The battery cell 20 can also have other structures. For example, the battery cell 20 includes a housing 22 and two end cap assemblies 23. The housing 22 is a hollow structure with openings on opposite sides. One end cap assembly 23 is fitted onto one opening of the housing 22 to form a sealed connection, thereby forming a sealed space 221 for accommodating the electrode assembly 21 and the electrolyte.

[0109] It should be noted that, in this embodiment of the application, the electrode assembly 21 housed within the housing 22 can be one or more. For example, in... Figure 3 In the middle, there are two electrode components 21, which are stacked in layers.

[0110] End cap assembly 23 is an assembly that covers the opening of housing 22 to isolate the internal environment of battery cell 20 from the external environment.

[0111] According to some embodiments of this application, refer to Figure 3 Please refer to further details. Figure 4 , Figure 4 This is a schematic diagram of the structure of an end cap assembly 23 provided in some embodiments of this application. This application provides an end cap assembly 23, which includes an end cap 231 and a pressure relief member 232. The pressure relief member 232 is disposed on the end cap 231 and has a groove 2321. The pressure relief member 232 is configured to crack along the groove 2321 when the internal pressure or temperature of the battery cell 20 reaches a threshold, thereby releasing the internal pressure of the battery cell 20. The hardness of the pressure relief member 232 is less than the hardness of the end cap 231.

[0112] The pressure relief component 232 is configured to crack along the groove 2321 when the internal pressure or temperature of the battery cell 20 reaches a threshold. In other words, when the internal pressure or temperature of the battery cell 20 reaches a predetermined value, the pressure relief component 232 will arch outward under the action of the internal gas of the battery cell 20, causing the pressure relief component 232 to crack along the groove 2321 to release the internal gas of the battery cell 20, thereby achieving the function of pressure relief.

[0113] Optionally, the pressure relief component 232 has a sheet-like structure, and the groove 2321 provided on the pressure relief component 232 can be a cross-shaped structure, a semi-circular cross-shaped structure, or a ring-shaped structure. For example, in... Figure 4 In the design, the groove 2321 on the pressure relief component 232 is an annular structure, and two semi-circular structures are formed within the annular structure, with the two semi-circular structures being tangent to each other. Furthermore, in the thickness direction of the end cap 231, the groove 2321 can be located on the side of the pressure relief component 232 facing the sealing space 221 of the housing 22, or it can be located on the side of the pressure relief component 232 away from the sealing space 221 of the housing 22.

[0114] In some embodiments, the end cap assembly 23 may further include a positive electrode terminal 233 and a negative electrode terminal 234, both of which are mounted on the end cap 231. Both the positive electrode terminal 233 and the negative electrode terminal 234 are used for electrical connection with the electrode assembly 21.

[0115] For example, such as Figure 4As shown, the pressure relief component 232 is disposed between the positive electrode terminal 233 and the negative electrode terminal 234.

[0116] The end cap assembly 23 with this structure facilitates the machining of grooves 2321 on the pressure relief component 232, ensuring the machining accuracy of the grooves 2321. This allows the pressure relief component 232 to crack along the grooves 2321 when the internal pressure or temperature of the battery cell 20 reaches a threshold, releasing the internal pressure of the battery cell 20 and reducing the risk of fire and explosion during use. Furthermore, while maintaining the rigidity of the end cap 231, it also allows the internal gas of the battery cell 20 to push against the grooves 2321. The groove 2321 is punched open, eliminating the need to process its depth excessively. This increases the wall thickness of the groove's bottom wall, improving the deformation resistance of the pressure relief component 232. This effectively reduces the likelihood of deformation of the groove's bottom wall under external forces, thus minimizing the impact resistance of the pressure relief component 232. Consequently, the pressure relief component 232 only cracks along the groove 2321 when the internal pressure or temperature of the battery cell 20 reaches a threshold, ensuring stable pressure relief. Furthermore, because the end cap 231 is harder than the pressure relief component 232, when the internal pressure of the battery cell 20 increases, the internal gas will preferentially cause the less hard pressure relief component 232 to crack, allowing it to function as a pressure relief component. This facilitates controllable venting direction of the battery cell 20.

[0117] According to some embodiments of this application, the melting point of the pressure relief component 232 is lower than that of the end cap 231.

[0118] By setting the melting point of the end cap 231 to be higher than that of the pressure relief component 232, the end cap 231 can withstand higher temperatures than the pressure relief component 232 when thermal runaway occurs inside the battery cell 20. This effectively reduces the premature melting of the end cap 231, allowing the internal gas of the battery cell 20 to be stably released through the pressure relief component 232, thereby effectively reducing the risk of fire and explosion of the battery cell 20.

[0119] In some embodiments, the end cap 231 has a melting point above 1000 degrees Celsius.

[0120] Optionally, the pressure relief component 232 can be made of aluminum or copper, and the end cap 231 can be made of steel or nickel.

[0121] By setting the melting point of end cap 231 to above 1000 degrees Celsius, end cap 231 can withstand most high-temperature environments during use, thereby effectively reducing the phenomenon of premature melting of end cap 231 and improving the safety of battery cell 20.

[0122] According to some embodiments of this application, the end cap 231 is made of steel.

[0123] The steel end cap 231 has high hardness and melting point, which helps to improve the structural strength and high-temperature resistance of the end cap 231, thereby effectively reducing the phenomenon of premature melting of the end cap 231 and providing better explosion protection. In addition, the end cap 231 made of this material is low in cost and easy to process and manufacture.

[0124] According to some embodiments of this application, the pressure relief component 232 is made of aluminum.

[0125] Using aluminum, a material with lower hardness, to make the pressure relief component 232 easier to machine grooves 2321 on, resulting in lower cost and allowing the internal gas of the battery cell 20 to more easily break through the pressure relief component 232, thereby achieving a better pressure relief effect.

[0126] According to some embodiments of this application, refer to Figure 4 Please refer to further details. Figure 5 , Figure 5 This is an exploded view of the end cap assembly 23 provided in some embodiments of this application. The end cap assembly 23 also includes a connector 235 and a limiting member 236. The connector 235 is connected to the end cap 231, and a pressure relief hole 2351 is provided on the connector 235 for communicating with the interior of the battery cell 20. A pressure relief member 232 covers the pressure relief hole 2351. The limiting member 236 is connected to the connector 235, and in the thickness direction of the end cap 231, the limiting member 236 and the connector 235 are used to clamp a portion of the pressure relief member 232.

[0127] The pressure relief hole 2351 is connected to the interior of the battery cell 20. That is, the pressure relief hole 2351 provided on the connector 235 is connected to the sealed space 221 of the housing 22 for accommodating the electrode assembly 21 and the electrolyte, so that the gas in the housing 22 can be released through the pressure relief hole 2351.

[0128] Optionally, in Figure 5In this design, the connecting member 235 and the limiting member 236 are separate structures. The limiting member 236, after being connected to the connecting member 235, exerts a pressing effect on the pressure relief member 232, so that the limiting member 236 and the connecting member 235 cooperate to clamp a portion of the pressure relief member 232. For example, the limiting member 236 and the connecting member 235 cooperate to clamp the edge portion of the pressure relief member 232. Of course, in other embodiments, the connecting member 235 and the limiting member 236 can also be an integral structure. For example, the limiting member 236 can be formed by folding or rolling the edge of the connecting member 235. That is, when the pressure relief member 232 is placed on the connecting member 235, by rolling or folding the edge of the connecting member 235, the edge of the connecting member 235 presses against the side of the pressure relief member 232 away from the connecting member 235, thereby achieving a clamping effect on the pressure relief member 232.

[0129] By connecting the limiting member 236 to the connector 235, the limiting member 236 and the connector 235 can cooperate to clamp the pressure relief member 232. This structure enables the pressure relief member 232 to be installed on the end cap 231, which is made of a different material. The connector 235 is provided with a pressure relief hole 2351 that communicates with the interior of the battery cell 20. The pressure relief member 232 covers the pressure relief hole 2351 so that the pressure relief member 232 can meet the pressure relief requirements of the battery cell 20.

[0130] According to some embodiments of this application, refer to Figure 5 Please refer to further details. Figure 6 and Figure 7 , Figure 6 This is a cross-sectional view of the end cap assembly 23 provided in some embodiments of this application. Figure 7 for Figure 6 The diagram shows a partial enlarged view of point A of the end cap assembly 23. The connector 235 includes a first connecting portion 2352 and a second connecting portion 2353. The first connecting portion 2352 is connected to the end cap 231, and a pressure relief hole 2351 is provided in the first connecting portion 2352. The second connecting portion 2353 surrounds the edge of the first connecting portion 2352. Both the limiting member 236 and the pressure relief member 232 are located on the inner periphery of the second connecting portion 2353, and the limiting member 236 is connected to the second connecting portion 2353. In the thickness direction of the end cap 231, the limiting member 236 and the first connecting portion 2352 are used to clamp the portion of the pressure relief member 232.

[0131] The first connecting portion 2352 and the second connecting portion 2353 are both annular structures extending circumferentially along the pressure relief hole 2351, meaning that both the first connecting portion 2352 and the second connecting portion 2353 are structures that surround the central axis of the pressure relief hole 2351. The second connecting portion 2353 surrounds the edge of the first connecting portion 2352, and the limiting member 236 and the pressure relief member 232 are both located on the inner circumferential side of the second connecting portion 2353. That is, the first connecting portion 2352 is connected to the inner circumferential surface of the second connecting portion 2353, so that after the limiting member 236 and the pressure relief member 232 are disposed on the inner circumferential side of the second connecting portion 2353, they can be placed on the first connecting portion 2352, thereby allowing the limiting member 236 to cooperate with the first connecting portion 2352 to clamp the pressure relief member 232.

[0132] Optionally, the first connecting portion 2352 and the second connecting portion 2353 are integrally formed, that is, the first connecting portion 2352 and the second connecting portion 2353 are integrally formed by casting or stamping. In other embodiments, the first connecting portion 2352 and the second connecting portion 2353 may also be separate structures, with the first connecting portion 2352 fixedly connected to the second connecting portion 2353 by welding, bonding, or other methods.

[0133] By configuring the connector 235 into two parts, a first connecting part 2352 and a second connecting part 2353, with the first connecting part 2352 connected to the end cap 231 and the second connecting part 2353 surrounding the outside of the first connecting part 2352, the limiting member 236 and the pressure relief member 232 can be disposed on the inner periphery of the second connecting part 2353. After the limiting member 236 is connected to the second connecting part 2353, the limiting member 236 can cooperate with the first connecting part 2352 to clamp the pressure relief member 232, thereby fixing the pressure relief member 232. The connector 235 with this structure is beneficial to improving the structural stability of the end cap assembly 23 and facilitates the assembly of the end cap assembly 23.

[0134] According to some embodiments of this application, please continue to refer to Figure 5 , Figure 6 and Figure 7 The end cap 231 is provided with a positioning hole 2311 that penetrates its inner and outer surfaces. At least a portion of the first connecting part 2352 is inserted into the positioning hole 2311.

[0135] The projection of the pressure relief hole 2351 on the thickness direction of the end cap 231 is located inside the positioning hole 2311. The positioning hole 2311 is connected to the pressure relief hole 2351 so that the pressure relief hole 2351 is connected to the sealing space 221 of the housing 22 of the battery cell 20.

[0136] Combination Figure 6 and Figure 7As shown, the diameter of the positioning hole 2311 is larger than the diameter of the pressure relief hole 2351, so that the first connecting part 2352 of the connector 235 can be inserted into the positioning hole 2311 to achieve positioning between the connector 235 and the end cap 231. Optionally, the positioning hole 2311 has an annular protrusion extending circumferentially along the hole wall, so that the positioning hole 2311 forms a stepped hole structure. A stepped groove is formed on the outer peripheral surface of the first connecting part 2352. When the first connecting part 2352 is inserted into the positioning hole 2311, the annular protrusion on the hole wall of the positioning hole 2311 can be engaged in the stepped groove of the first connecting part 2352. Thus, the positioning hole 2311 can not only position the connector 235, but also limit the connector 235 in the thickness direction of the end cap 231.

[0137] By providing a positioning hole 2311 on the end cap 231, at least a portion of the first connecting part 2352 can be inserted into the positioning hole 2311 to position and limit the connecting part 235, thereby improving the installation accuracy between the connecting part 235 and the end cap 231.

[0138] According to some embodiments of this application, please continue to refer to Figure 5 , Figure 6 and Figure 7 The limiting member 236 is an annular structure that extends circumferentially along the pressure relief member 232.

[0139] The limiting member 236 is an annular structure extending circumferentially along the pressure relief member 232, that is, the limiting member 236 is a structure surrounding the geometric center point of the pressure relief member 232. In other embodiments, the limiting member 236 can also be other structures, such as multiple limiting blocks arranged at intervals circumferentially along the pressure relief member 232, which are used to cooperate with the first connecting portion 2352 of the connecting member 235 to clamp a part of the pressure relief member 232.

[0140] By setting the limiting member 236 as an annular structure extending circumferentially along the pressure relief member 232, the limiting member 236 can cooperate with the connecting member 235 to clamp the pressure relief member 232 circumferentially, thereby improving the stability of the pressure relief member 232 installed on the end cover 231.

[0141] In some embodiments, the limiting member 236 is located on the outer periphery of the groove 2321.

[0142] The limiting member 236 is located on the outer periphery of the groove 2321, that is, the groove 2321 on the pressure relief member 232 is located on the inner periphery of the limiting member 236, so that the limiting member 236 can effectively avoid the groove 2321.

[0143] By setting the limiting member 236 on the outer periphery of the groove 2321 of the pressure relief member 232, that is, when the limiting member 236 and the connecting member 235 cooperate to clamp the pressure relief member 232, the limiting member 236 can effectively avoid the location of the groove 2321 of the pressure relief member 232. Thus, when the internal pressure or temperature of the battery cell 20 reaches the threshold, the limiting member 236 can effectively alleviate the impact of the limiting member 236 on the pressure relief member 232 needing to crack along the groove 2321.

[0144] According to some embodiments of this application, the material of the connector 235 is the same as that of the end cap 231, and the connector 235 is welded to the end cap 231.

[0145] For example, both the connector 235 and the end cap 231 are made of steel.

[0146] It should be noted that in other embodiments, the connector 235 can also be connected to the end cap 231 by means of screwing or bonding.

[0147] By setting the material of the connector 235 to be the same as that of the end cap 231, the connector 235 can be welded to the end cap 231, thereby effectively improving the connection strength between the connector 235 and the end cap 231, which in turn helps to improve the structural strength of the end cap assembly 23.

[0148] According to some embodiments of this application, the limiting member 236 is made of the same material as the connecting member 235, and the limiting member 236 is welded to the connecting member 235.

[0149] For example, both the limiting member 236 and the connecting member 235 are made of steel.

[0150] It should be noted that in other embodiments, the limiting member 236 can also be connected to the second connecting portion 2353 of the connector 235 by means of screwing or bonding.

[0151] By setting the material of the limiting member 236 to be the same as that of the connecting member 235, the limiting member 236 can be welded to the connecting member 235, thereby effectively improving the connection strength between the limiting member 236 and the connecting member 235, which in turn helps to improve the structural strength of the end cap assembly 23.

[0152] According to some embodiments of this application, please continue to refer to Figure 5 , Figure 6 and Figure 7 The end cap assembly 23 also includes a seal 237. At least a portion of the seal 237 is located between the connector 235 and the pressure relief member 232 in the thickness direction of the end cap 231, and the seal 237 is used to seal the connector 235 and the pressure relief member 232.

[0153] The sealing element 237 is an annular structure extending circumferentially along the pressure relief hole 2351. The sealing element 237 is disposed between the pressure relief element 232 and the first connecting portion 2352 of the connector 235. That is, in the thickness direction of the end cap 231, the sealing element 237 is disposed on the side of the pressure relief element 232 away from the limiting element 236, so that the sealing element 237 can seal the gap between the pressure relief element 232 and the first connecting portion 2352 of the connector 235.

[0154] For example, the material of the seal 237 can be rubber, silicone or plastic, etc.

[0155] By providing a seal 237 between the connector 235 and the pressure relief component 232, the seal 237 can seal the gap between the connector 235 and the pressure relief component 232, thereby reducing the leakage of internal gas from the battery cell 20 through the gap between the connector 235 and the pressure relief component 232, thus reducing the possibility of pressure relief component 232 failure, and thus improving the safety of the battery cell 20 with this end cap assembly 23.

[0156] According to some embodiments of this application, please refer to Figure 7 In the thickness direction of the end cap 231, the connector 235 has a contact surface 2354 for the seal 237 to abut against. A limiting protrusion 2355 is provided on the contact surface 2354. The limiting protrusion 2355 is an annular structure extending circumferentially along the pressure relief hole 2351. The seal 237 is sleeved on the outer peripheral surface of the limiting protrusion 2355.

[0157] The connector 235 has a contact surface 2354 for the sealing member 237 to abut against. That is, in the thickness direction of the end cap 231, the side of the first connecting portion 2352 of the connector 235 facing the pressure relief member 232 is the contact surface 2354 for the sealing member 237 to abut against.

[0158] The limiting protrusion 2355 protrudes from the abutment surface 2354 and is located on the inner circumference of the seal 237. For example, the limiting protrusion 2355 and the first connecting part 2352 are integral structures, that is, the limiting protrusion 2355 and the first connecting part 2352 are integrally formed by casting or stamping. In other embodiments, the limiting protrusion 2355 and the first connecting part 2352 can also be separate structures. The limiting protrusion 2355 is connected to the abutment surface 2354 by welding or bonding.

[0159] The connector 235 is provided with an abutment surface 2354 for the seal 237 to abut against, so that the seal 237 is located between the abutment surface 2354 and the pressure relief member 232. The abutment surface 2354 is provided with a limiting protrusion 2355 extending circumferentially along the pressure relief hole 2351. By fitting the seal 237 onto the outer circumferential surface of the limiting protrusion 2355, the limiting protrusion 2355 can play a certain limiting role on the seal 237, so as to restrict the seal 237 from moving between the connector 235 and the pressure relief member 232, thereby improving the sealing effect of the seal 237 on the connector 235 and the pressure relief member 232.

[0160] According to some embodiments of this application, please refer to Figure 5 , Figure 6 and Figure 7 The end cap assembly 23 also includes an insulating member 238. In the thickness direction of the end cap 231, at least a portion of the insulating member 238 is located between the pressure relief member 232 and the limiting member 236 to insulate the pressure relief member 232 and the limiting member 236.

[0161] Among them, the pressure relief component 232 and the limiting component 236 are insulated and isolated, that is, by setting an insulating component 238 between the pressure relief component 232 and the limiting component 236, no electrical conduction can be formed between the pressure relief component 232 and the limiting component 236.

[0162] For example, the insulating element 238 may be made of polyethylene terephthalate (PET), polypropylene (PP), polycarbonate (PC), or polyvinyl chloride (PVC), etc.

[0163] By distributing at least a portion of the insulating member 238 between the pressure relief member 232 and the limiting member 236, insulation isolation is achieved between the pressure relief member 232 and the limiting member 236. In other words, the insulating member 238 provides electrical insulation between the pressure relief member 232 and the limiting member 236, reducing the possibility of current conduction between them. This improves the service life of the pressure relief member 232 and the safety of the battery cell 20 with this end cap assembly 23. It should be noted that when the materials of the pressure relief member 232 and the limiting member 236 are different, the insulating member 238 effectively reduces the potential difference between them, thus mitigating corrosion and further extending the service life of the end cap assembly 23.

[0164] According to some embodiments of this application, refer to Figure 7 Please refer to further details. Figure 8 and Figure 9 , Figure 8 A cross-sectional view of the limiting member 236 provided in some embodiments of this application. Figure 9 This is a cross-sectional view of an insulating member 238 provided in some embodiments of this application. The insulating member 238 includes a first insulator 2381. In the thickness direction of the end cap 231, a first limiting groove 2361 is provided on the side of the limiting member 236 facing the pressure relief member 232. The first limiting groove 2361 is used to accommodate at least a portion of the first insulator 2381 to restrict the movement of the insulating member 238 along a preset direction X, which is perpendicular to the thickness direction of the end cap 231.

[0165] The limiting member 236 includes a body portion 2362, a first limiting portion 2363, and a second limiting portion 2364. The body portion 2362 is connected to the second connecting portion 2353 of the connecting member 235. In the thickness direction of the end cap 231, the first limiting portion 2363 and the second limiting portion 2364 both protrude from the side of the body portion 2362 facing the pressure relief member 232. The first limiting portion 2363 and the second limiting portion 2364 are both annular structures extending circumferentially along the pressure relief hole 2351. The first limiting portion 2363 is located outside the second limiting portion 2364. That is, the first limiting portion 2363 and the second limiting portion 2364 are arranged at intervals along a preset direction X, so that the first limiting portion 2363, the body portion 2362, and the second limiting portion 2364 together define a first limiting groove 2361 for accommodating the first insulator 2381 of the insulating member 238.

[0166] It should be noted that the first limiting groove 2361 is used to accommodate at least a portion of the first insulator 2381 to restrict the movement of the insulating member 238 along the preset direction X. This means that the first limiting groove 2361 is used to restrict the movement of the insulating member 238 within the range of the preset direction X. In other words, under the premise of ensuring that the insulating member 238 provides insulation and isolation to the limiting member 236 and the pressure relief member 232, the first limiting groove 2361 can allow the insulating member 238 to move within a certain range of the preset direction X.

[0167] By providing a first limiting groove 2361 on the side of the limiting member 236 facing the pressure relief member 232, at least a portion of the first insulator 2381 of the insulating member 238 can be accommodated in the first limiting groove 2361. This effectively restricts the movement of the insulating member 238 along a preset direction X perpendicular to the thickness direction of the end cover 231, thereby reducing the phenomenon of the insulating member 238 disengaging from the pressure relief member 232 and the limiting member 236. This further improves the insulating effect of the insulating member 238 in insulating and isolating the pressure relief member 232 and the limiting member 236.

[0168] Based on some embodiments of this application, please continue to refer to Figure 7 , Figure 8 and Figure 9In the thickness direction of the end cap 231, a second limiting groove 2381a is provided on the side of the first insulator 2381 facing the pressure relief member 232. The second limiting groove 2381a is used to accommodate part of the pressure relief member 232 to restrict the pressure relief member 232 from moving along the preset direction X.

[0169] The first insulator 2381 includes a first insulating portion 2381b, a second insulating portion 2381c, and a third insulating portion 2381d connected in sequence. The second insulating portion 2381c is accommodated within the first limiting groove 2361 of the limiting member 236. In the thickness direction of the end cap 231, both the first insulating portion 2381b and the third insulating portion 2381d protrude from the side of the second insulating portion 2381c facing the pressure relief member 232. Both the first insulating portion 2381b and the third insulating portion 2381d are annular structures extending circumferentially along the pressure relief hole 2351. The third insulating portion 2381d is located inside the first insulating portion 2381b, that is, the third insulating portion 2381d and the first insulating portion 2381b are arranged at intervals along a predetermined direction X. The first insulating portion 2381b, the second insulating portion 2381c, and the third insulating portion 2381d together define the second limiting groove 2381a for accommodating the portion of the pressure relief member 232.

[0170] Optionally, refer to Figure 10 and Figure 11 As shown, Figure 10 This is a schematic diagram of the structure of the pressure relief component 232 provided in some embodiments of this application. Figure 11 This is a cross-sectional view of a pressure relief member 232 provided in some embodiments of this application. The pressure relief member 232 includes a pressure relief portion 2322 and a fixing portion 2323, with a groove 2321 provided on the pressure relief portion 2322. The fixing portion 2323 is an annular structure extending circumferentially along the pressure relief portion 2322 and located on the outer periphery of the pressure relief portion 2322 along a predetermined direction X. At least a portion of the fixing portion 2323 is accommodated within a second limiting groove 2381a of the first insulator 2381. In the thickness direction of the end cap 231, the outer surface of the fixing portion 2323 is closer to the outside of the battery cell 20 than the outer surface of the pressure relief portion 2322, and a stepped surface 2324 is formed between the outer surface of the fixing portion 2323 and the outer surface of the pressure relief portion 2322, so that the third insulating portion 2381d can abut against the stepped surface 2324, thereby realizing the limiting function of the pressure relief member 232.

[0171] Among them, a stepped surface 2324 is formed between the outer surface of the fixing part 2323 and the outer surface of the pressure relief part 2322. That is, in the thickness direction of the end cap 231, the fixing part 2323 protrudes from the side of the pressure relief part 2322 away from the sealing member 237, so that the fixing part 2323 and the pressure relief part 2322 form a stepped structure, thereby forming a stepped surface 2324 between the outer surface of the fixing part 2323 and the outer surface of the pressure relief part 2322.

[0172] It should be noted that the second limiting groove 2381a is used to accommodate at least a portion of the fixing part 2323 to restrict the pressure relief member 232 from moving along the preset direction X. This means that the second limiting groove 2381a is used to restrict the pressure relief member 232 to move within a range in the preset direction X. In other words, on the premise that the pressure relief member 232 does not detach from the first connecting part 2352 of the limiting member 236 and the connecting member 235, the second limiting groove 2381a can allow the pressure relief member 232 to move within a certain range in the preset direction X. For example, when the pressure relief component 232 arches under the action of the internal gas of the battery cell 20, the fixing part 2323 of the pressure relief component 232 will move along the preset direction X. At this time, the movement of the pressure relief component 232 can be restricted within a certain range by the second limiting groove 2381a of the insulating component 238, so as to ensure that the pressure relief component 232 does not detach from the limiting component 236 and the first connecting part 2352 of the connecting component 235, thereby effectively reducing the risk of gaps between the limiting component 236 and the connecting component 235.

[0173] By providing a second limiting groove 2381a on the side of the first insulator 2381 facing the pressure relief member 232, the second limiting groove 2381a can accommodate part of the pressure relief member 232. This effectively restricts the movement of the pressure relief member 232 in the preset direction X when the internal gas of the battery cell 20 arches the pressure relief member 232, thereby reducing the phenomenon of large gaps between the pressure relief member 232 and the connecting member 235 due to misalignment. This helps to improve the installation stability of the pressure relief member 232 and reduces the phenomenon of leakage of internal gas in the battery cell 20.

[0174] Based on some embodiments of this application, please continue to refer to Figure 7 , Figure 8 and Figure 9 The insulating element 238 may also include a second insulator 2382, which protrudes from the inner circumferential surface of the first insulator 2381 and is located between the limiting element 236 and the pressure relief element 232 in the thickness direction of the end cap 231.

[0175] The second insulator 2382 is disposed between the second limiting part 2364 of the limiting member 236 and the pressure relief part 2322 of the pressure relief member 232. The second insulator 2382 is connected to the third insulating part 2381d of the first insulator 2381. The second insulator 2382 protrudes from the inner circumferential surface of the first insulator 2381. That is, the second insulator 2382 is an annular structure connected to the inner circumferential surface of the third insulating part 2381d and extending circumferentially along the pressure relief hole 2351.

[0176] For example, the second insulator 2382 and the first insulator 2381 are an integral structure. In other embodiments, the second insulator 2382 and the first insulator 2381 may also be separate structures. For example, the second insulator 2382 may be connected to the third insulating portion 2381d of the first insulator 2381 by means of bonding or other methods.

[0177] It should be noted that the second insulator 2382 is located on the outer periphery of the groove 2321 of the pressure relief part 2322, that is, the groove 2321 is located on the inner periphery of the second insulator 2382 in the preset direction X, so that the second insulator 2382 can effectively avoid the location of the groove 2321.

[0178] By protruding the second insulator 2382 onto the inner circumferential surface of the first insulator 2381, and by positioning the second insulator 2382 between the limiting member 236 and the pressure relief member 232 in the thickness direction of the end cap 231, the pressure relief member 232 is separated from the groove sidewall of the first limiting groove 2361, thereby improving the insulating isolation effect of the insulator 238 on the pressure relief member 232 and the limiting member 236.

[0179] According to some embodiments of this application, refer to Figure 12 and Figure 13 , Figure 12 A cross-sectional view of the end cap assembly 23 provided in some embodiments of this application. Figure 13 for Figure 12 The enlarged view of part B of the end cap assembly 23 is shown. In the thickness direction of the end cap 231, the limiting member 236 is provided with a first limiting groove 2361 on the side facing the pressure relief member 232. The first limiting groove 2361 is used to accommodate a portion of the pressure relief member 232 to restrict the pressure relief member 232 from moving along a preset direction X, which is perpendicular to the thickness direction of the end cap 231.

[0180] The first limiting groove 2361 is used to accommodate at least a portion of the pressure relief member 232 to restrict the movement of the pressure relief member 232 along a preset direction X. This means that the first limiting groove 2361 restricts the movement of the pressure relief member 232 within a range along the preset direction X. In other words, while ensuring that the pressure relief member 232 does not detach from the first connecting portion 2352 of the limiting member 236 and the connecting member 235, the first limiting groove 2361 allows the pressure relief member 232 to move within a certain range along the preset direction X. For example, when the pressure relief member 232 arches under the action of the internal gas of the battery cell 20, the edge of the pressure relief member 232 may move along the preset direction X. At this time, the first limiting groove 2361 of the limiting member 236 can restrict the movement of the pressure relief member 232 within a certain range, ensuring that the pressure relief member 232 does not detach from the first connecting portion 2352 of the limiting member 236 and the connecting member 235, thereby effectively reducing the risk of a gap between the limiting member 236 and the connecting member 235.

[0181] By providing a first limiting groove 2361 on the side of the limiting member 236 facing the pressure relief member 232, the first limiting groove 2361 can accommodate part of the pressure relief member 232. This effectively restricts the movement of the pressure relief member 232 in the preset direction X when the internal gas of the battery cell 20 arches the pressure relief member 232, thereby reducing the phenomenon of large gaps between the pressure relief member 232 and the connecting member 235 due to misalignment. This helps to improve the installation stability of the pressure relief member 232 and reduces the phenomenon of leakage of internal gas in the battery cell 20.

[0182] In some embodiments, Figure 11 In this design, the pressure relief component 232 includes a pressure relief portion 2322 and a fixing portion 2323. The pressure relief portion 2322 is provided with a groove 2321, and is configured to crack along the groove 2321 when the internal pressure or temperature of the battery cell 20 reaches a threshold, thereby releasing the internal pressure of the battery cell 20. The fixing portion 2323 is located on the outer periphery of the pressure relief portion 2322 along a predetermined direction X, and at least a portion of the fixing portion 2323 is accommodated within a first limiting groove 2361. In the thickness direction of the end cap 231, the outer surface of the fixing portion 2323 is closer to the outside of the battery cell 20 than the outer surface of the pressure relief portion 2322, and a stepped surface 2324 is formed between the outer surface of the fixing portion 2323 and the outer surface of the pressure relief portion 2322.

[0183] Among them, a stepped surface 2324 is formed between the outer surface of the fixing part 2323 and the outer surface of the pressure relief part 2322. That is, in the thickness direction of the end cap 231, the fixing part 2323 protrudes from the side of the pressure relief part 2322 away from the sealing member 237, thereby forming a stepped structure between the fixing part 2323 and the pressure relief part 2322 to form the stepped surface 2324.

[0184] By providing two parts, a pressure relief part 2322 and a fixing part 2323, and a groove 2321 on the pressure relief part 2322, the pressure relief part 2322 can relieve pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold. By providing the fixing part 2323 on the outer periphery of the pressure relief part 2322, and the outer surface of the fixing part 2323 being further away from the interior of the battery cell 20 than the outer surface of the pressure relief part 2322, a stepped surface 2324 is formed between the fixing part 2323 and the pressure relief part 2322. After at least a portion of the fixing part 2323 is accommodated in the first limiting groove 2361 of the limiting member 236, the stepped surface 2324 between the fixing part 2323 and the pressure relief part 2322 can be abutted by the groove sidewall of the first limiting groove 2361. Thus, the first limiting groove 2361 achieves the limiting effect of the pressure relief part 232 through this structure. The structure is simple and has high stability.

[0185] According to some embodiments of this application, please refer to Figure 7 , Figure 8 and Figure 9 The limiting member 236 includes a body portion 2362, a first limiting portion 2363, and a second limiting portion 2364. The body portion 2362 is connected to the connecting member 235. In the thickness direction of the end cap 231, the body portion 2362 is used to press against the fixing portion 2323. The first limiting portion 2363 and the second limiting portion 2364 protrude from the side of the body portion 2362 facing the pressure relief member 232. Both the first limiting portion 2363 and the second limiting portion 2364 are annular structures extending circumferentially along the pressure relief hole 2351. The second limiting portion 2364 is located inside the first limiting portion 2363. The second limiting portion 2364, the body portion 2362, and the first limiting portion 2363 together define the first limiting groove 2361. The end cap assembly 23 also includes an insulating member 238, at least a portion of which is located between the fixing portion 2323 and the body portion 2362 in the thickness direction of the end cap 231, so as to insulate the pressure relief member 232 and the limiting member 236.

[0186] The limiting member 236 is provided with a body portion 2362, a first limiting portion 2363, and a second limiting portion 2364. The body portion 2362 is used to press against the fixing portion 2323 of the pressure relief member 232 so that the body portion 2362 can cooperate with the connecting member 235 to clamp the pressure relief member 232. By both the first limiting portion 2363 and the second limiting portion 2364 protruding on the side of the body portion 2362 facing the pressure relief member 232, and the second limiting portion 2364 being disposed inside the first limiting portion 2363, the second limiting portion 2364 and the first limiting portion 2363 are arranged at intervals in a preset direction X, so that the second limiting portion 2364, the body portion 2362, and the first limiting portion 2363 together define a first limiting groove 2361 for accommodating the fixing portion 2323 of the pressure relief member 232.

[0187] By providing an insulating member 238 between the fixing part 2323 and the main body part 2362, insulation isolation is achieved between the pressure relief member 232 and the limiting member 236. In other words, the insulating member 238 can achieve electrical insulation between the pressure relief member 232 and the limiting member 236, reducing the phenomenon of current conduction between the pressure relief member 232 and the limiting member 236, thereby reducing the safety hazards of the battery cell 20 with this end cap assembly 23.

[0188] According to some embodiments of this application, please refer to Figure 7 , Figure 8 and Figure 9 The insulating member 238 includes a first insulator 2381, which includes a first insulating portion 2381b, a second insulating portion 2381c, and a third insulating portion 2381d. The second insulating portion 2381c is accommodated within a first limiting groove 2361. In the thickness direction of the end cap 231, the first insulating portion 2381b and the third insulating portion 2381d protrude from the side of the second insulating portion 2381c facing the pressure relief member 232. Both the first insulating portion 2381b and the third insulating portion 2381d are annular structures extending circumferentially along the pressure relief hole 2351. The third insulating portion 2381d is located inside the first insulating portion 2381b. The first insulating portion 2381b, the second insulating portion 2381c, and the third insulating portion 2381d together define a second limiting groove 2381a. The second limiting groove 2381a is used to accommodate a portion of the fixing portion 2323 to restrict the movement of the pressure relief member 232 along a preset direction X. The first insulating portion 2381b is at least partially located between the inner peripheral surface of the first limiting portion 2363 and the outer peripheral surface of the pressure relief member 232. And / or the third insulating portion 2381d is at least partially located between the outer peripheral surface of the second limiting portion 2364 and the stepped surface 2324.

[0189] In the thickness direction of the end cap 231, both the first insulating portion 2381b and the third insulating portion 2381d protrude from the side of the second insulating portion 2381c facing the pressure relief member 232. The first insulating portion 2381b is at least partially located between the inner peripheral surface of the first limiting portion 2363 and the outer peripheral surface of the pressure relief member 232, that is, the first insulating portion 2381b extends along the thickness direction of the end cap 231 to the area between the outer peripheral surface of the pressure relief member 232 and the inner peripheral surface of the first limiting portion 2363. The third insulating portion 2381d is located at least partially between the outer peripheral surface of the second limiting portion 2364 and the step surface 2324, separating the outer peripheral surface of the pressure relief member 232 and the inner peripheral surface of the first limiting portion 2363. That is, the third insulating portion 2381d extends along the thickness direction of the end cap 231 to the area between the outer peripheral surface of the second limiting portion 2364 and the step surface 2324 of the pressure relief member 232, thereby separating the outer peripheral surface of the second limiting portion 2364 and the step surface 2324 of the pressure relief member 232.

[0190] By accommodating the second insulating portion 2381c within the first limiting groove 2361 of the limiting member 236, and by having the first insulating portion 2381b and the third insulating portion 2381d protrude from the side of the second insulating portion 2381c facing the pressure relief member 232, the first insulating portion 2381b, the second insulating portion 2381c, and the third insulating portion 2381d define the second limiting groove 2381a for accommodating the fixing portion 2323 of the pressure relief member 232. Thus, while the limiting member 236 restricts the movement of the insulating member 238 along the preset direction X, the limiting member 236 can indirectly restrict the movement of the pressure relief member 232 along the preset direction X through the insulating member 238, and can also effectively ensure the insulation isolation between the limiting member 236 and the pressure relief member 232. Furthermore, by providing at least a portion of the first insulating portion 2381b between the inner peripheral surface of the first limiting portion 2363 and the outer peripheral surface of the pressure relief member 232, insulation isolation between the first limiting portion 2363 and the pressure relief member 232 can be achieved. Similarly, by providing at least a portion of the third insulating portion 2381d between the outer peripheral surface of the second limiting portion 2364 and the stepped surface 2324 of the pressure relief member 232, insulation isolation between the second limiting portion 2364 and the pressure relief member 232 can be achieved.

[0191] Based on some embodiments of this application, please continue to refer to Figure 7 , Figure 8 and Figure 9 The insulating member 238 also includes a second insulator 2382 connected to the third insulating portion 2381d. The second insulator 2382 protrudes from the inner peripheral surface of the third insulating portion 2381d and is located between the second limiting portion 2364 and the pressure relief portion 2322 in the thickness direction of the end cap 231.

[0192] The second insulator 2382 protrudes from the inner circumferential surface of the third insulating part 2381d, that is, the second insulator 2382 is an annular structure connected to the inner circumferential surface of the third insulating part 2381d and extending circumferentially along the pressure relief hole 2351.

[0193] The insulating member 238 is also provided with a second insulator 2382 connected to the third insulating portion 2381d. By protruding the second insulator 2382 on the inner peripheral surface of the third insulating portion 2381d and disposing the second insulator 2382 in the thickness direction of the end cap 231 between the second limiting portion 2364 of the limiting member 236 and the pressure relief portion 2322 of the pressure relief member 232, the pressure relief portion 2322 of the pressure relief member 232 and the second limiting portion 2364 of the limiting member 236 are separated. This improves the insulating effect of the insulating member 238 in insulating and isolating the pressure relief member 232 and the limiting member 236.

[0194] According to some embodiments of this application, this application also provides a battery cell 20, including an electrode assembly 21, a housing 22, and an end cap assembly 23 of any of the above embodiments. The housing 22 has an opening for receiving the electrode assembly 21. The end cap 231 of the end cap assembly 23 is used to close the opening.

[0195] According to some embodiments of this application, the material of the housing 22 is the same as that of the end cap 231, and the housing 22 is welded to the end cap 231.

[0196] For example, both the housing 22 and the end cap 231 are made of steel.

[0197] It should be noted that in other embodiments, the housing 22 can also be connected to the end cap 231 by means of screwing, snap-fitting or gluing.

[0198] The battery cell 20 with this structure can achieve welding between the casing 22 and the end cap 231, thereby effectively providing the connection strength between the casing 22 and the end cap assembly 23. Furthermore, since the casing 22 and the end cap 231 are made of the same material, the hardness of the casing 22 is greater than that of the pressure relief component 232. This improves the impact resistance of the casing 22, ensuring that when the internal pressure of the battery cell 20 increases, the internal gas will preferentially impact the less hard pressure relief component 232, achieving stable pressure relief and reducing the safety hazards of the battery cell 20. In addition, the casing 22 made of this material can withstand high temperatures in the event of thermal runaway within the battery cell 20, reducing the possibility of premature melting of the casing 22 before the pressure relief component 232 releases pressure, thus reducing the risk of fire and explosion of the battery cell 20.

[0199] According to some embodiments of this application, this application also provides a battery 100, including a housing 10 and a battery cell 20 of any of the above embodiments, wherein the housing 10 is used to house the battery cell 20.

[0200] According to some embodiments of this application, this application also provides an electrical device including a battery 100 of any of the above schemes, and the battery 100 is used to provide electrical energy to the electrical device.

[0201] The electrical device can be any of the aforementioned devices or systems that use battery 100.

[0202] According to some embodiments of this application, see Figures 4-11As shown, this application provides an end cap assembly 23, including an end cap 231, a pressure relief member 232, a connector 235, a limiting member 236, a sealing member 237, and an insulating member 238. The end cap 231 is used to cover the opening of the housing 22 of the battery cell 20, and the end cap 231 has a positioning hole 2311 penetrating its inner and outer surfaces. The pressure relief member 232 includes a pressure relief portion 2322 and a fixing portion 2323 extending circumferentially along the pressure relief portion 2322. The fixing portion 2323 is connected to the outer peripheral side of the pressure relief portion 2322 and protrudes from the outer surface of the pressure relief portion 2322 along the thickness direction of the end cap 231. The pressure relief portion 2322 has a groove 2321, and the pressure relief portion 2322 is configured to crack along the groove 2321 when the internal pressure or temperature of the battery cell 20 reaches a threshold, thereby releasing the internal pressure of the battery cell 20. A portion of the connector 235 is inserted into the positioning hole 2311 and connected to the end cap 231. The connector 235 has a pressure relief hole 2351 that communicates with the positioning hole 2311. A pressure relief component 232 covers the pressure relief hole 2351. A limiting component 236 is connected to the connector 235 and cooperates with the connector 235 to clamp the fixing portion 2323 of the pressure relief component 232, thereby installing the pressure relief component 232 onto the end cap 231. In the thickness direction of the end cap 231, a sealing component 237 is disposed between the connector 235 and the pressure relief component 232 to seal the gap between them. An insulating member 238 is disposed on the side of the pressure relief member 232 facing away from the sealing member 237, and is at least partially located between the limiting member 236 and the pressure relief member 232. The limiting member 236 has a first limiting groove 2361 on the side facing the pressure relief member 232 for accommodating a portion of the insulating member 238, and the insulating member 238 has a second limiting groove 2381a on the side facing the pressure relief member 232 for accommodating a fixing portion 2323 of the pressure relief member 232, thereby insulating and isolating the pressure relief member 232 from the limiting member 236. The end cap 231, the connecting member 235, and the limiting member 236 are all made of steel, while the pressure relief member 232 is made of aluminum.

[0203] This application also provides a method for manufacturing an end cap assembly 23, please refer to... Figure 14 , Figure 14 This is a schematic flowchart of a method for manufacturing an end cap assembly 23 provided in some embodiments of this application. The manufacturing method includes:

[0204] S100: End cap 231 is provided;

[0205] S200: Provides a pressure relief component 232, which has a groove 2321. The pressure relief component 232 is configured to crack along the groove 2321 when the internal pressure or temperature of the battery cell 20 reaches a threshold, so as to release the internal pressure of the battery cell 20.

[0206] S300: Install the pressure relief component 232 onto the end cap 231.

[0207] Among them, the hardness of the pressure relief component 232 is less than that of the end cap 231.

[0208] In the above method, the order of steps S100 and S200 is not restricted. Step S100 can be executed first, followed by step S200, or step S200 can be executed first, followed by step S100.

[0209] It should be noted that the relevant structure of the end cap assembly 23 manufactured by the manufacturing method provided in the above embodiments can be found in the end cap assembly 23 provided in the foregoing embodiments, and will not be described again here.

[0210] This application embodiment also provides a manufacturing apparatus 2000 for an end cap assembly 23, see reference. Figure 15 , Figure 15 This is a schematic block diagram of a manufacturing apparatus 2000 for an end cap assembly 23 provided in some embodiments of this application. The manufacturing apparatus 2000 includes a first providing device 2100, a second providing device 2200, and an assembly device 2300.

[0211] A first providing device 2100 is used to provide an end cap 231. A second providing device 2200 is used to provide a pressure relief component 232, which has a groove 2321. The pressure relief component 232 is configured to crack along the groove 2321 when the internal pressure or temperature of the battery cell 20 reaches a threshold, thereby releasing the internal pressure of the battery cell 20. An assembly device 2300 is used to install the pressure relief component 232 onto the end cap 231. The hardness of the pressure relief component 232 is less than the hardness of the end cap 231.

[0212] It should be noted that the relevant structure of the end cap assembly 23 manufactured by the manufacturing equipment 2000 provided in the above embodiments can be found in the end cap assembly 23 provided in the foregoing embodiments, and will not be repeated here.

[0213] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0214] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An end cap assembly for a battery cell, characterized in that, The end cap assembly includes: End caps; and A pressure relief component is disposed on the end cap and has a groove. The pressure relief component is configured to crack along the groove when the internal pressure or temperature of the battery cell reaches a threshold, so as to release the internal pressure of the battery cell. The hardness of the pressure relief component is less than that of the end cap. The end cap assembly further includes a connector and a limiting member. The connector is connected to the end cap and has a pressure relief hole for communicating with the interior of the battery cell. The pressure relief member covers the pressure relief hole, and the limiting member is connected to the connector. In the thickness direction of the end cap, the limiting member and the connector are used to clamp a portion of the pressure relief member. The end cap assembly further includes an insulating member, which includes a first insulator. In the thickness direction of the end cap, at least a portion of the insulating member is located between the pressure relief member and the limiting member. The limiting member has a first limiting groove on the side facing the pressure relief member. The first limiting groove is used to accommodate at least a portion of the first insulator to restrict the movement of the insulating member along a preset direction, which is perpendicular to the thickness direction of the end cap.

2. The end cap assembly according to claim 1, characterized in that, The melting point of the pressure relief component is lower than that of the end cap.

3. The end cap assembly according to claim 1, characterized in that, The end cap has a melting point above 1000 degrees Celsius.

4. The end cap assembly according to claim 1, characterized in that, The end cap is made of steel.

5. The end cap assembly according to claim 1, characterized in that, The pressure relief component is made of aluminum.

6. The end cap assembly according to any one of claims 1-5, characterized in that, The connector includes: A first connecting part is connected to the end cap, and the pressure relief hole is provided in the first connecting part; The second connecting portion surrounds the edge of the first connecting portion; Both the limiting member and the pressure relief member are located on the inner circumferential side of the second connecting portion, and the limiting member is connected to the second connecting portion. In the thickness direction of the end cap, the limiting member and the portion of the first connecting portion are used to clamp the pressure relief member.

7. The end cap assembly according to claim 6, characterized in that, The end cap is provided with positioning holes that penetrate its inner and outer surfaces; At least a portion of the first connecting part is inserted into the positioning hole.

8. The end cap assembly according to any one of claims 1-5, characterized in that, The limiting member is a ring structure extending circumferentially along the pressure relief member.

9. The end cap assembly according to any one of claims 1-5, characterized in that, The limiting member is located on the outer periphery of the groove.

10. The end cap assembly according to any one of claims 1-5, characterized in that, The connector is made of the same material as the end cap, and the connector is welded to the end cap.

11. The end cap assembly according to any one of claims 1-5, characterized in that, The limiting member is made of the same material as the connecting member, and the limiting member is welded to the connecting member.

12. The end cap assembly according to any one of claims 1-5, characterized in that, The end cap assembly also includes a seal; In the thickness direction of the end cap, at least a portion of the seal is located between the connector and the pressure relief member, and the seal is used to seal the connector and the pressure relief member.

13. The end cap assembly according to claim 12, characterized in that, In the thickness direction of the end cap, the connector has a contact surface against which the seal abuts; A limiting protrusion is provided on the abutment surface. The limiting protrusion is an annular structure extending circumferentially along the pressure relief hole. The sealing element is sleeved on the outer peripheral surface of the limiting protrusion.

14. The end cap assembly according to any one of claims 1-5, characterized in that, In the thickness direction of the end cap, a second limiting groove is provided on the side of the first insulator facing the pressure relief member. The second limiting groove is used to accommodate a portion of the pressure relief member to restrict the pressure relief member from moving along the preset direction.

15. The end cap assembly according to any one of claims 1-5, characterized in that, The insulating element further includes a second insulator: The second insulator protrudes from the inner circumferential surface of the first insulator and is located between the limiting member and the pressure relief member in the thickness direction of the end cap.

16. The end cap assembly according to any one of claims 1-5, characterized in that, In the thickness direction of the end cap, a first limiting groove is provided on the side of the limiting member facing the pressure relief member. The first limiting groove is used to accommodate a portion of the pressure relief member to restrict the pressure relief member from moving in a preset direction, which is perpendicular to the thickness direction of the end cap.

17. The end cap assembly according to claim 16, characterized in that, The pressure relief component includes a pressure relief part and a fixing part; The pressure relief section is provided with the groove, and the pressure relief section is configured to crack along the groove when the internal pressure or temperature of the battery cell reaches a threshold, so as to release the internal pressure of the battery cell. The fixing part is located on the outer periphery of the pressure relief part along the preset direction, and at least a portion of the fixing part is accommodated in the first limiting groove; In the thickness direction of the end cap, the outer surface of the fixing part is closer to the outside of the battery cell than the outer surface of the pressure relief part, and a stepped surface is formed between the outer surface of the fixing part and the outer surface of the pressure relief part.

18. The end cap assembly according to claim 17, characterized in that, The limiting member includes a body part, a first limiting part, and a second limiting part; The main body is connected to the connector. In the thickness direction of the end cap, the main body is used to press against the fixing part. The first limiting part and the second limiting part protrude from the side of the main body facing the pressure relief member. The first limiting part and the second limiting part are both annular structures extending circumferentially along the pressure relief hole. The second limiting part is located inside the first limiting part. The second limiting part, the main body, and the first limiting part together define the first limiting groove. The end cap assembly further includes an insulating member, at least a portion of which is located between the fixing portion and the body portion in the thickness direction of the end cap, so as to insulate the pressure relief member and the limiting member.

19. The end cap assembly according to claim 18, characterized in that, The insulating component includes a first insulator, which includes a first insulating portion, a second insulating portion, and a third insulating portion. The second insulating part is accommodated within the first limiting groove. In the thickness direction of the end cap, the first insulating part and the third insulating part protrude from the side of the second insulating part facing the pressure relief member. The first insulating part and the third insulating part are both annular structures extending circumferentially along the pressure relief hole. The third insulating part is located inside the first insulating part. The first insulating part, the second insulating part, and the third insulating part together define the second limiting groove. The second limiting groove is used to accommodate a portion of the fixing part to restrict the movement of the pressure relief member along the preset direction. The first insulating portion is at least partially located between the inner peripheral surface of the first limiting portion and the outer peripheral surface of the pressure relief member; and / or the third insulating portion is at least partially located between the outer peripheral surface of the second limiting portion and the stepped surface.

20. The end cap assembly according to claim 19, characterized in that, The insulating component further includes a second insulator connected to the third insulating portion. The second insulator protrudes from the inner circumferential surface of the third insulating portion and is located between the second limiting portion and the pressure relief portion in the thickness direction of the end cap.

21. A single battery cell, characterized in that, include: Electrode assembly; A housing having an opening for accommodating the electrode assembly; as well as The end cap assembly according to any one of claims 1-20, wherein the end cap is used to close the opening.

22. The battery cell according to claim 21, characterized in that, The shell is made of the same material as the end cap, and the shell is welded to the end cap.

23. A battery, characterized in that, include: The battery cell according to claim 21 or 22; as well as A housing for containing the individual battery cells.

24. An electrical appliance, characterized in that, Includes the battery according to claim 23.

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