End cover, battery monomer, battery and electric equipment

Abstract

The invention provides an end cover, a battery monomer, a battery and electric equipment, and relates to the field of batteries. The end cover comprises a cover body and a reinforcing part. The cover body is provided with a pressure relief area, the reinforcing part is arranged on one side of the cover body in the thickness direction in a protruding mode, and the reinforcing part is arranged around the pressure relief area. The reinforcing part is arranged around the outer side of the pressure relief area of the end cover, so that the strength of the pressure relief area is enhanced, and the impact resistance of the pressure relief area is improved. Therefore, when the end cover is subjected to external impact, the reinforcing part can absorb the energy of the external impact, the impact force transmitted to the pressure relief area is reduced, the pressure relief area is prevented from being damaged due to the external impact to a certain extent, and the normal pressure relief function of the pressure relief area can be ensured. And the pressure relief area is prevented from being opened when the internal pressure of the single battery does not reach the detonation pressure, so that the normal work of the single battery is ensured.

Description

End caps, battery cells, batteries and electrical equipment Technical Field

[0001] The present application relates to the field of batteries, and in particular to an end cover, a battery cell, a battery and an electrical device. Background Art

[0002] Batteries are widely used in new energy applications, such as electric vehicles and new energy vehicles, which have become a new development trend in the automotive industry. The end caps of battery cells are equipped with a pressure relief structure to release internal pressure when the cell's internal pressure reaches the detonation pressure. However, in the case of an inverted battery cell, the pressure relief structure often opens prematurely, resulting in a failure to achieve normal pressure relief.

[0003] Summary of the Invention

[0004] The purpose of the embodiments of the present application is to provide an end cover, a battery cell, a battery and an electrical device, which aims to improve the problem in the related art that the pressure relief structure often opens prematurely, resulting in the inability to achieve normal pressure relief function.

[0005] In a first aspect, an embodiment of the present application provides an end cover, which includes a cover body and a reinforcement portion, wherein the cover body has a pressure relief area; the reinforcement portion is protruded on one side of the cover body in the thickness direction, and the reinforcement portion is arranged around the pressure relief area.

[0006] In the above technical solution, a reinforcement portion is provided around the outer side of the pressure relief area of ​​the end cap, which strengthens the pressure relief area and improves its impact resistance. Thus, when the end cap is subjected to an external impact, the reinforcement portion can absorb the energy of the external impact, reducing the magnitude of the impact force transmitted to the pressure relief area, and to a certain extent, prevent the pressure relief area from being damaged by the external impact, thereby ensuring that the pressure relief area can perform its normal pressure relief function. In other words, it prevents the pressure relief area from opening when the internal pressure of the battery cell has not reached the detonation pressure, thereby ensuring the normal operation of the battery cell.

[0007] As an optional technical solution of an embodiment of the present application, the reinforcement portion includes two first connecting segments and two second connecting segments. Along the circumference of the pressure relief zone, one first connecting segment, one second connecting segment, another first connecting segment and another second connecting segment are connected end to end in sequence to form a closed structure; the two first connecting segments are arranged opposite to each other along a first direction, and the two second connecting segments are arranged opposite to each other along a second direction, and the first direction is perpendicular to the second direction; wherein the size of the first connecting segment in the first direction is larger than the size of the second connecting segment in the second direction.

[0008] In the above technical solution, the two first connecting segments and the two second connecting segments are located in four different directions. The two first connecting segments and the two second connecting segments are connected to form a closed structure, which has strong strength and can effectively enhance the impact resistance of the pressure relief zone. In addition, because the size of the first connecting segment in the first direction is larger than the size of the second connecting segment in the second direction, the size of the second connecting segment in the first direction can be made smaller than the size of the first connecting segment in the second direction. This ensures that the reinforcement capacity of the first connecting segment is equivalent to that of the second connecting segment, reduces the space occupied by the reinforcement, and reduces material waste.

[0009] As an optional technical solution of an embodiment of the present application, the size of the first connecting segment in the first direction is 5% to 35% of the size of the first connecting segment in the second direction.

[0010] In the above technical solution, when the dimension of the first connecting segment in the first direction is less than 5% of the dimension of the first connecting segment in the second direction, the first connecting segment's reinforcement effect is insufficient, and when the end cap is subjected to an external impact, the energy of the external impact cannot be effectively absorbed. When the dimension of the first connecting segment in the first direction is greater than 35% of the dimension of the first connecting segment in the second direction, the first connecting segment occupies a large volume, and further increasing the dimension of the first connecting segment in the first direction after it has already provided sufficient reinforcement results in material waste.

[0011] As an optional technical solution of an embodiment of the present application, the size of the second connecting segment in the second direction is 5% to 30% of the size of the second connecting segment in the first direction.

[0012] In the above technical solution, when the dimension of the second connecting segment in the second direction is less than 5% of its dimension in the first direction, the second connecting segment's reinforcement effect is insufficient, and when the end cap is subjected to an external impact, the energy of the external impact cannot be effectively absorbed. When the dimension of the second connecting segment in the second direction is greater than 30% of its dimension in the first direction, the second connecting segment occupies a large volume, and further increasing the dimension of the second connecting segment in the second direction after it has already provided sufficient reinforcement results in material waste.

[0013] As an optional technical solution of an embodiment of the present application, the reinforcement portion includes at least one arc segment, and the first connecting segment and the second connecting segment are connected by the arc segment.

[0014] In the above technical solution, by providing an arc segment to connect the first connecting segment and the second connecting segment, stress concentration at the corner can be reduced and the force can be optimized.

[0015] As an optional technical solution of an embodiment of the present application, a groove is provided at a position of the cover body corresponding to the reinforcement portion. Along the thickness direction, the cover body has a relative inner surface and outer surface, the reinforcement portion is protruded from the inner surface, and the groove is recessed from the outer surface toward the inner surface.

[0016] In the above technical solution, by providing a groove on the outer surface of the cover body, the groove plays a thinning role, so that the thickness of the pressure relief zone is reduced. When the internal pressure of the battery cell reaches the detonation pressure, the pressure relief zone is more easily opened by the internal pressure, thereby achieving pressure relief. The provision of the groove makes the pressure relief zone more easily opened by the internal pressure, and also more easily opened by external impact. Therefore, when the end cover is subjected to an external impact, the reinforcement portion can absorb the energy of the impact and reduce the magnitude of the impact force transmitted to the pressure relief zone, so as to reduce the impact of the external impact on the pressure relief zone, and to a certain extent avoid the pressure relief zone from being damaged by the external impact, thereby ensuring that the normal pressure relief function can be achieved, that is, preventing the pressure relief zone from opening when the internal pressure of the battery cell has not reached the detonation pressure, so as to ensure the normal operation of the battery cell.

[0017] As an optional technical solution of an embodiment of the present application, the inner side wall of the reinforcement portion defines a first space, and the side wall and bottom wall of the groove define a second space. Along the thickness direction, the first space and the second space are located on both sides of the pressure relief zone.

[0018] In the above technical solution, by locating the pressure relief zone between the first space and the second space, it is ensured that the pressure relief zone is located within the range of the groove, and the groove has a better thinning effect.

[0019] As an optional technical solution of an embodiment of the present application, the pressure relief zone is provided with a pressure relief groove.

[0020] In the above technical solution, a pressure relief groove is opened in the pressure relief zone to form a thinned position on the pressure relief zone. When the internal pressure of the battery cell reaches the detonation pressure, the pressure relief zone is opened with the pressure relief groove as the boundary to release the internal pressure.

[0021] As an optional technical solution of an embodiment of the present application, the pressure relief groove is a closed groove extending along a closed track connected end to end.

[0022] In the above technical solution, by setting the pressure relief groove as a closed groove extending along a closed track connected end to end, after the pressure relief area is opened, the cover body can form a larger opening at the position corresponding to the pressure relief area, thereby improving the pressure relief efficiency.

[0023] As an optional technical solution of an embodiment of the present application, along the thickness direction, the reinforcement portion and the pressure relief groove are respectively located on both sides of the pressure relief area.

[0024] In the above technical solution, the reinforcement portion is arranged on the side of the pressure relief area away from the pressure relief groove, which facilitates processing and manufacturing.

[0025] As an optional technical solution of an embodiment of the present application, the pressure relief groove includes a first groove section, a second groove section, a third groove section and a fourth groove section connected in sequence; along the first direction, the first groove section and the third groove section are arranged relative to each other, and the maximum distance between the first groove section and the third groove section is a first distance; along the second direction, the second groove section and the fourth groove section are arranged relative to each other, and the minimum distance between the second groove section and the fourth groove section is a second distance; the second distance is greater than the first distance, and the first direction, the second direction and the thickness direction are perpendicular to each other.

[0026] In the above technical solution, the weak area formed by the first, second, third and fourth groove segments on the pressure relief area is large, which can be easily opened by the internal pressure when the detonation pressure inside the battery cell is reached. In addition, the structure is simple and easy to form and manufacture.

[0027] As an optional technical solution of an embodiment of the present application, the first slot segment and the third slot segment are straight slots; and / or the second slot segment and the fourth slot segment are arc slots.

[0028] In the above technical solution, the second and fourth slot sections are arcuate slots. A weak point is formed in the middle of the second and fourth slot sections on the cover body. This weak point is the initial opening point of the pressure relief zone, allowing the pressure relief zone to open promptly when the detonation pressure inside the battery cell is reached. The first and third slot sections are both straight slots extending along the width of the cover body. These slots are arranged parallel to each other. After the cover body is split along the second and fourth slot sections, it can more easily open along the first and third slot sections, increasing the opening speed of the pressure relief zone and achieving rapid pressure relief.

[0029] As an optional technical solution of the embodiment of the present application, the cover body partially protrudes along the thickness direction to form a convex portion, and the reinforcement portion is protruded on one side of the convex portion in the thickness direction.

[0030] In the above technical solution, the cover body partially protrudes along the thickness direction of the cover body to form a convex portion, and a concave space will be formed on the side of the cover body opposite to the convex portion in its thickness direction. On the one hand, it can accommodate the components inside the battery cell, which is beneficial to improving the energy density of the battery cell. On the other hand, it can improve the bending strength of the end cover and improve the impact resistance of the end cover.

[0031] In a second aspect, an embodiment of the present application further provides a battery cell, which includes an electrode assembly, a shell and the above-mentioned end cover; the shell has a accommodating space with one end open, and the accommodating space is used to accommodate the electrode assembly; the end cover is connected to the shell and closes the opening.

[0032] In a third aspect, an embodiment of the present application further provides a battery, which includes a box and the above-mentioned battery cells, and the battery cells are accommodated in the box.

[0033] As an optional technical solution of the embodiment of the present application, the end cover is arranged on a side of the battery cell close to the bottom wall of the box body.

[0034] In the above technical solution, the end cover is arranged on a side of the battery cell close to the bottom wall of the box body, that is, the battery cell is placed upside down in the box body.

[0035] In a fourth aspect, an embodiment of the present application further provides an electrical device, which includes the above-mentioned battery, and the battery is used to provide electrical energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings without creative work.

[0037] FIG1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0038] FIG2 is an exploded view of a battery provided in some embodiments of the present application;

[0039] FIG3 is a schematic structural diagram of a battery cell provided in some embodiments of the present application;

[0040] FIG4 is a schematic structural diagram of an end cap provided in some embodiments of the present application;

[0041] FIG5 is a bottom view of an end cap provided in some embodiments of the present application;

[0042] FIG6 is a schematic top view of an end cap provided in some embodiments of the present application;

[0043] FIG7 is a cross-sectional view taken along the CC line in FIG6 ;

[0044] FIG8 is an enlarged view of position E in FIG7 ;

[0045] FIG9 is an enlarged view of position F in FIG6 ;

[0046] FIG10 is a schematic structural diagram of an end cap provided in some other embodiments of the present application;

[0047] FIG11 is a schematic top view of end caps provided in other embodiments of the present application;

[0048] FIG12 is a cross-sectional view of the GG position in FIG11 .

[0049] Icons: 10-housing; 11-first part; 12-second part; 20-battery cell; 21-end cover; 211-cover body; 2111-pressure relief area; 2112-outer surface; 2113-inner surface; 2114-convex portion; 212-reinforcement portion; 2121-first connecting section; 2122-second connecting section; 2123-arc section; 2124-first space; 213-pressure relief groove; 2131-first groove section; 2132-second groove section; 2133-third groove section; 2134-fourth groove section; 214-groove; 22-electrode assembly; 23-shell; 100-battery; 200-controller; 300-motor; 1000-vehicle. DETAILED DESCRIPTION

[0050] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0051] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0052] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0053] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0054] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0055] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0056] The term "plurality" used in this application refers to two or more (including two).

[0057] In this application, battery cells may include lithium-ion secondary battery cells, lithium-ion primary battery cells, lithium-sulfur battery cells, sodium-lithium-ion battery cells, sodium-ion battery cells, or magnesium-ion battery cells, etc., and the embodiments of this application do not limit this. Battery cells may be cylindrical, flat, rectangular, or other shapes, etc., and the embodiments of this application do not limit this. Battery cells are generally divided into three types based on the packaging method: cylindrical battery cells, prismatic battery cells, and soft-pack battery cells, and the embodiments of this application do not limit this.

[0058] The battery referred to in the embodiments of this application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in this application may include a battery module or a battery pack. A battery generally includes a casing that encloses one or more battery cells. The casing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0059] A battery cell includes an electrode assembly and an electrolyte. The electrode assembly consists of a positive electrode sheet, a negative electrode sheet, and a separator. A battery cell primarily operates by the movement of metal ions between the positive and negative electrode sheets. The positive electrode sheet comprises a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive electrode collector. The portion of the positive electrode collector not coated with the positive active material layer protrudes from the portion coated with the positive active material layer. The portion of the positive electrode collector not coated with the positive active material layer serves as the positive electrode tab. For lithium-ion batteries, for example, the positive electrode 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. The negative electrode sheet comprises a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative electrode collector. The portion of the negative electrode collector not coated with the negative active material layer protrudes from the portion coated with the negative active material layer. The portion of the negative electrode collector not coated with the negative active material layer serves as the negative electrode tab. The negative electrode current collector can be made of copper, and the negative active material can be carbon or silicon, among others. To ensure high current flow without melting, multiple positive tabs are stacked together, and multiple negative tabs are stacked together. The separator can be made of materials such as PP (polypropylene) or PE (polyethylene). Furthermore, the electrode assembly can be a wound or laminated structure, but the present invention is not limited thereto.

[0060] The development of battery technology must take into account multiple design factors at the same time, such as energy density, cycle life, discharge capacity, charge and discharge rate and other performance parameters. In addition, battery safety must also be considered.

[0061] For battery cells, in order to ensure the safety of the battery cells, a pressure relief structure can be set on the end cover of the battery cells. When the internal pressure of the battery cells reaches the detonation pressure, the pressure relief structure opens to release the pressure inside the battery cells, thereby reducing the risk of battery cell explosion and fire.

[0062] The inventors have noticed that in the scenario where the battery cell is inverted, the pressure relief structure often opens prematurely, resulting in the inability to achieve the normal pressure relief function.

[0063] The inventors further discovered that when the battery cell is inverted, the end cover is more susceptible to external impact, and the external impact force is easily transmitted to the location of the pressure relief structure, causing the pressure relief structure to open prematurely, resulting in the failure to achieve the normal pressure relief function.

[0064] In view of this, an embodiment of the present application provides an end cover, including a cover body and a reinforcement portion, the cover body having a pressure relief area, the reinforcement portion protruding from one side of the cover body in the thickness direction, and the reinforcement portion is arranged around the pressure relief area.

[0065] The end cap's pressure relief area is surrounded by a reinforcement, which strengthens the area and improves its impact resistance. When the end cap is subjected to an external impact, the reinforcement absorbs the energy of the impact, reducing the impact force transmitted to the pressure relief area. This, to a certain extent, prevents damage to the pressure relief area due to the external impact, thereby ensuring that the pressure relief area can perform its normal pressure relief function. This prevents the pressure relief area from opening when the internal pressure of the battery cell has not reached the detonation pressure, thereby ensuring the normal operation of the battery cell.

[0066] The technical solutions described in the embodiments of the present application are applicable to batteries and electrical devices using batteries.

[0067] Electrically powered devices may include vehicles, mobile phones, portable devices, laptop computers, ships, spacecraft, electric toys, and electric tools. Spacecraft include airplanes, rockets, space shuttles, and spacecraft. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys. Electric tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0068] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle 1000 as an example.

[0069] Please refer to Figure 1, which is a schematic structural diagram of a vehicle 1000 provided in some embodiments of the present application. The vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 can be provided at the bottom, head or tail of the vehicle 1000. The battery 100 can be used to power the vehicle 1000. For example, the battery 100 can serve as an 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 power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0070] In some embodiments of the present application, the battery 100 can serve not only as an operating power source for the vehicle 1000, but also as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0071] Please refer to Figure 2, which is an exploded view of a battery 100 provided in some embodiments of the present application. The battery 100 includes a housing 10 and a battery cell 20, with the battery cell 20 housed within the housing 10. The housing 10 provides a storage space for the battery cell 20 and can have various structures. In some embodiments, the housing 10 can include a first portion 11 and a second portion 12, which overlap each other and together define a storage space for the battery cell 20. The second portion 12 can be a hollow structure with one end open. The first portion 11 can be a plate-like structure, with the first portion 11 overlapping the open side of the second portion 12, so that the first portion 11 and the second portion 12 together define a storage space. Alternatively, the first portion 11 and the second portion 12 can each be a hollow structure with one end open, with the open side of the first portion 11 overlapping 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 have various shapes, such as a cylinder, a rectangular parallelepiped, etc.

[0072] In the battery 100, there may be multiple battery cells 20, and the multiple battery cells 20 may be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections among the multiple battery cells 20. The multiple battery cells 20 may be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery cell 20 may be housed within the housing 10. Alternatively, the battery 100 may be constructed by first connecting multiple battery cells 20 in series, in parallel, or in a hybrid connection to form a battery module, which is then connected in series, in parallel, or in a hybrid connection to form a complete battery module, and then housed within the housing 10. The battery 100 may also include other structures, such as a busbar assembly for electrically connecting the multiple battery cells 20.

[0073] Each battery cell 20 may be a secondary battery cell or a primary battery cell; it may also be a lithium-sulfur battery cell, a sodium-ion battery cell, or a magnesium-ion battery cell, but is not limited thereto. The battery cell 20 may be cylindrical, flat, rectangular, or in other shapes.

[0074] Please refer to Figure 3, which is a schematic diagram of the exploded structure of a battery cell 20 provided in some embodiments of the present application. A battery cell 20 is the smallest unit that makes up a battery 100. As shown in Figure 3, a battery cell 20 includes an end cap 21, an electrode assembly 22, a housing 23, and other functional components.

[0075] The end cap 21 refers to a component that covers the opening of the housing 23 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap 21 can be adapted to the shape of the housing 23 to match the housing 23. Optionally, the end cap 21 can be made of a material with a certain hardness and strength (such as an aluminum alloy). In this way, the end cap 21 is less likely to deform when squeezed or collided, so that the battery cell 20 can have a higher structural strength and improved safety performance. Functional components such as electrode terminals (not shown in the figure) can be provided on the end cap 21. The electrode terminals can be used to electrically connect to the electrode assembly 22 for outputting or inputting electrical energy from the battery cell 20. The material of the end cap 21 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this embodiment of the present application does not impose any special restrictions on this. In some embodiments, an insulating member can also be provided on the inner side of the end cap 21. The insulating member can be used to isolate the electrical connection components in the housing 23 from the end cap 21 to reduce the risk of short circuits. For example, the insulating member may be made of plastic, rubber, or the like.

[0076] The housing 23 is a component that cooperates with the end cap 21 to form the internal environment of the battery cell 20. This internal environment can be used to accommodate the electrode assembly 22, electrolyte, and other components. The housing 23 and the end cap 21 can be separate components. An opening can be provided in the housing 23, and the end cap 21 is placed over the opening to form the internal environment of the battery cell 20. Alternatively, the end cap 21 and the housing 23 can be integrated. Specifically, the end cap 21 and the housing 23 can form a common connection surface before other components are inserted into the housing. When the interior of the housing 23 is to be enclosed, the end cap 21 is placed over the housing 23. The housing 23 can be of various shapes and sizes, such as a rectangular parallelepiped, a cylinder, or a hexagonal prism. Specifically, the shape of the housing 23 can be determined based on the specific shape and size of the electrode assembly 22. The housing 23 can be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this embodiment of the present application does not impose any particular limitations on this.

[0077] The electrode assembly 22 is a component in the battery cell 20 where electrochemical reactions occur. One or more electrode assemblies 22 may be contained in the housing 23. The electrode assembly 22 is mainly formed by winding or stacking positive and negative electrode sheets, and a separator is usually provided between the positive and negative electrode sheets. The parts of the positive and negative electrode sheets with active materials constitute the main body of the electrode assembly 22, and the parts of the positive and negative electrode sheets without active materials each constitute a tab. The positive tab and the negative tab may be located together at one end of the main body or respectively at both ends of the main body. During the charge and discharge process of the battery 100, the positive electrode active material and the negative electrode active material react with the electrolyte, and the tabs connect the electrode terminals to form a current loop.

[0078] Please refer to Figures 4 and 5. Figure 4 is a schematic diagram of the structure of the end cap 21 provided in some embodiments of the present application. Figure 5 is a schematic bottom view of the end cap 21 provided in some embodiments of the present application. The embodiments of the present application provide an end cap 21, which includes a cap body 211 and a reinforcement portion 212. The cap body 211 has a pressure relief area 2111. The reinforcement portion 212 is protruding from one side of the cap body 211 in the thickness direction and is arranged around the pressure relief area 2111.

[0079] The cover body 211 is the main structure of the end cap 21 and is primarily used to seal the opening of the housing 23. The shape of the cover body 211 is adapted to the shape of the opening of the housing 23. For example, if the opening of the housing 23 is rectangular, the shape of the cover body 211 is also rectangular. If the opening of the housing 23 is circular, the shape of the cover body 211 is also circular.

[0080] The pressure relief area 2111 is the area on the cover body 211 that implements the pressure relief function. For example, the pressure relief area 2111 may be the area on the end cover 21 where the explosion-proof disk is welded. In another example, if the end cover 21 is provided with a pressure relief groove 213, the pressure relief area 2111 may include the area inside the pressure relief groove 213 and part of the area outside the pressure relief groove 213.

[0081] The reinforcement portion 212 is a raised structure that protrudes from one side of the cover body 211 in the thickness direction (direction D as shown in FIG8 ) and is disposed around the pressure relief area 2111. The reinforcement portion 212 can be disposed on the surface of the cover body 211 facing the interior of the housing 23, or on the surface of the cover body 211 facing away from the housing 23. Taking the cover body 211 as a rectangular flat plate structure as an example, the cover body 211 has an inner surface 2113 and an outer surface 2112 that are opposite to each other in the thickness direction. The inner surface 2113 of the cover body 211 faces the interior of the housing 23, and the outer surface 2112 of the cover body 211 is disposed away from the housing 23. The reinforcement portion 212 can be disposed on either the inner surface 2113 or the outer surface 2112 of the cover body 211.

[0082] The reinforcement portion 212 can have a variety of shapes. For example, if the reinforcement portion 212 is in a racetrack shape, the pressure relief area 2111 is the portion of the cover body 211 enclosed within the inner circle of the racetrack. Alternatively, if the reinforcement portion 212 is in a rectangular shape, the pressure relief area 2111 is the portion of the cover body 211 enclosed within the rectangular circle. For another example, if the reinforcement portion 212 is a U-shaped protrusion extending along a U-shaped trajectory, the pressure relief area 2111 is the portion enclosed within the U-shaped protrusion.

[0083] The pressure relief area 2111 of the end cap 21 is surrounded by a reinforcement portion 212, which strengthens the pressure relief area 2111 and improves its impact resistance. Thus, when the end cap 21 is subjected to an external impact, the reinforcement portion 212 can absorb the energy of the external impact, reducing the magnitude of the impact force transmitted to the pressure relief area 2111. This, to a certain extent, prevents the pressure relief area 2111 from being damaged by the external impact, thereby ensuring that the pressure relief area 2111 can perform its normal pressure relief function. This prevents the pressure relief area 2111 from opening when the internal pressure of the battery cell 20 has not reached the detonation pressure, thereby ensuring the normal operation of the battery cell 20.

[0084] Referring to Figure 5 , in some embodiments, the reinforcement portion 212 includes two first connecting segments 2121 and two second connecting segments 2122. Along the circumference of the pressure relief area 2111, one first connecting segment 2121, one second connecting segment 2122, another first connecting segment 2121, and another second connecting segment 2122 are sequentially connected end-to-end to form a closed structure. The two first connecting segments 2121 are arranged opposite each other along a first direction, and the two second connecting segments 2122 are arranged opposite each other along a second direction, with the first direction being perpendicular to the second direction. The first connecting segment 2121 has a larger dimension in the first direction than the second connecting segment 2122 in the second direction.

[0085] The two first connecting segments 2121 and the two second connecting segments 2122 are respectively parts of the reinforcement portion 212 located at four different directions. In this embodiment, the two first connecting segments 2121 and the two second connecting segments 2122 are all straight protrusions extending along a straight trajectory. "A first connecting segment 2121, a second connecting segment 2122, another first connecting segment 2121 and another second connecting segment 2122 are connected end to end in sequence to form a closed structure" includes both the tail end of a first connecting segment 2121 being directly connected to the head end of a second connecting segment 2122, and the tail end of a first connecting segment 2121 being indirectly connected to the head end of another second connecting segment 2122 through an intermediate structure. Similarly, the tail end of a second connecting segment 2122 can be directly connected to the head end of another first connecting segment 2121, or indirectly connected through an intermediate structure.

[0086] Since the first connecting segment 2121 and the second connecting segment 2122 are both straight protrusions, "the two first connecting segments 2121 are arranged relative to each other along the first direction (direction A as shown in Figure 5), and the two second connecting segments 2122 are arranged relative to each other along the second direction (direction B as shown in Figure 5)" can also be understood as the two first connecting segments 2121 are arranged in parallel in the first direction, and the two second connecting segments 2122 are arranged in parallel in the second direction.

[0087] In this embodiment, referring to FIG5 , the length of the first connecting segment 2121 in the second direction (L1 as shown in FIG5 ) is greater than the length of the second connecting segment 2122 in the first direction (L2 as shown in FIG5 ). Thus, the side on which the second connecting segment 2122 is located is the short side of the reinforcing portion 212, and the side on which the second connecting segment 2122 is located is the long side of the reinforcing portion 212. Because the two corners of the short side are close together, they provide reinforcement. If the dimension of the first connecting segment 2121 in the first direction (D1 as shown in FIG5 ) is equal to the dimension of the second connecting segment 2122 in the second direction (D2 as shown in FIG5 ), the reinforcement portion 212 is more strongly reinforced on the short side and less so on the long side.

[0088] In this embodiment, by making the dimension D1 of the first connecting segment 2121 in the first direction larger than the dimension D2 of the second connecting segment 2122 in the second direction, the reinforcement degree of the reinforcing portion 212 at the short side is equal to that at the long side.

[0089] The two first connecting segments 2121 and the two second connecting segments 2122 are located in four different directions. The two first connecting segments 2121 and the two second connecting segments 2122 are connected to form a closed structure, which has strong strength and can effectively enhance the impact resistance of the pressure relief area 2111. In addition, because the dimension D1 of the first connecting segment 2121 in the first direction is greater than the dimension D2 of the second connecting segment 2122 in the second direction, the dimension L2 of the second connecting segment 2122 in the first direction can be made smaller than the dimension L1 of the first connecting segment 2121 in the second direction. This ensures that the reinforcement capacity of the first connecting segment 2121 and the second connecting segment 2122 is equivalent, reducing the space occupied by the reinforcement portion 212 and reducing material waste.

[0090] In some embodiments, the dimension D1 of the first connecting segment 2121 in the first direction is 5% to 35% of the dimension L1 of the first connecting segment 2121 in the second direction.

[0091] In this embodiment, the first connecting segment 2121 extends along the second direction, and the "dimension D1 of the first connecting segment 2121 in the first direction" is the width of the first connecting segment 2121, and the "dimension L1 of the first connecting segment 2121 in the second direction" is the length of the first connecting segment 2121. The phrase "dimension D1 of the first connecting segment 2121 in the first direction is 5% to 35% of the dimension L1 of the first connecting segment 2121 in the second direction" can also be understood as meaning that the width of the first connecting segment 2121 is 5% to 35% of the length of the first connecting segment 2121.

[0092] When the dimension D1 of the first connecting segment 2121 in the first direction is less than 5% of the dimension L1 of the first connecting segment 2121 in the second direction, the first connecting segment 2121 does not provide sufficient reinforcement, and when the end cap 21 is subjected to an external impact, the energy of the external impact cannot be effectively absorbed. When the dimension D1 of the first connecting segment 2121 in the first direction is greater than 35% of the dimension L1 of the first connecting segment 2121 in the second direction, the volume occupied by the first connecting segment 2121 is large, and further increasing the dimension D1 of the first connecting segment 2121 in the first direction after it has already provided sufficient reinforcement results in material waste.

[0093] In some embodiments, a dimension D2 of the second connecting segment 2122 in the second direction is 5% to 30% of a dimension L2 of the second connecting segment 2122 in the first direction.

[0094] In this embodiment, the second connecting segment 2122 extends along the first direction, and the "dimension D2 of the second connecting segment 2122 in the second direction" is the width of the second connecting segment 2122, and the "dimension L2 of the second connecting segment 2122 in the first direction" is the length of the second connecting segment 2122. The phrase "dimension D2 of the second connecting segment 2122 in the second direction is 5% to 30% of the dimension L2 of the second connecting segment 2122 in the first direction" can also be understood as meaning that the width of the second connecting segment 2122 is 5% to 30% of the length of the second connecting segment 2122.

[0095] When the dimension D2 of the second connecting section 2122 in the second direction is less than 5% of the dimension L2 of the second connecting section 2122 in the first direction, the reinforcing effect of the second connecting section 2122 is insufficient, and when the end cap 21 is subjected to an external impact, the energy of the external impact cannot be effectively absorbed. When the dimension D2 of the second connecting section 2122 in the second direction is greater than 30% of the dimension L2 of the second connecting section 2122 in the first direction, the volume occupied by the second connecting section 2122 is large, and further increasing the dimension D2 of the second connecting section 2122 in the second direction after it has already provided sufficient reinforcing effect will also result in material waste.

[0096] Referring to FIG. 5 , in some embodiments, the reinforcement portion 212 includes at least one arc segment 2123 , and a first connecting segment 2121 and a second connecting segment 2122 are connected via the arc segment 2123 .

[0097] The arc segment 2123 is a raised structure extending along an arc trajectory. The reinforcement portion 212 can have one arc segment 2123, two arc segments 2123, three arc segments 2123, or four arc segments 2123. The first connecting segment 2121 and the second connecting segment 2122 are indirectly connected by the arc segment 2123 to achieve an arc transition.

[0098] By providing the arc segment 2123 to connect the first connecting segment 2121 and the second connecting segment 2122 , stress concentration at the corner can be reduced and the force can be optimized.

[0099] Please refer to Figures 6, 7, and 8. Figure 6 is a schematic top view of the end cap 21 provided in some embodiments of the present application. Figure 7 is a cross-sectional view of the CC position in Figure 6. Figure 8 is an enlarged view of the E position in Figure 7. In some embodiments, a groove 214 is provided at a position of the cover body 211 corresponding to the reinforcement portion 212. Along the thickness direction, the cover body 211 has an inner surface 2113 and an outer surface 2112 that are opposite to each other. The reinforcement portion 212 is protruding from the inner surface 2113, and the groove 214 is recessed from the outer surface 2112 toward the inner surface 2113.

[0100] “A groove 214 is provided at a position of the cover body 211 corresponding to the reinforcing portion 212 ” means that the projection of the outline of the groove 214 falls within the projection range of the reinforcing portion 212 along the thickness direction.

[0101] The inner surface 2113 refers to the surface of the cover body 211 close to the housing 23 , and the outer surface 2112 refers to the surface of the cover body 211 away from the housing 23 .

[0102] The groove 214 is a groove-shaped structure that penetrates the outer surface 2112 of the cover body 211 and extends from the outer surface 2112 to the inner surface 2113. The shape of the groove 214 is not limited. For example, the groove 214 can be rectangular or circular.

[0103] By providing a groove 214 on the outer surface 2112 of the cover body 211, the groove 214 plays a thinning role, so that the thickness of the pressure relief zone 2111 is reduced. When the internal pressure of the battery cell 20 reaches the detonation pressure, the pressure relief zone 2111 is more easily opened by the internal pressure, thereby achieving pressure relief. The provision of the groove 214 makes the pressure relief zone 2111 more easily opened by the internal pressure, and also more easily opened by external impact. Therefore, when the end cover 21 is subjected to an external impact, the reinforcement portion 212 can absorb the energy of the impact and reduce the magnitude of the impact force transmitted to the pressure relief zone 2111, so as to reduce the impact of the external impact on the pressure relief zone 2111, and to a certain extent avoid the pressure relief zone 2111 from being damaged by the external impact, thereby ensuring that the normal pressure relief function can be achieved.

[0104] 8 , in some embodiments, the inner sidewall of the reinforcement portion 212 defines a first space 2124 , and the sidewalls and bottom wall of the groove 214 define a second space. The first space 2124 and the second space are located on both sides of the pressure relief area 2111 along the thickness direction.

[0105] The first space 2124 is defined by the inner wall of the reinforcement portion 212 . Along the thickness direction, the first space 2124 is located on a side of the pressure relief area 2111 close to the reinforcement portion 212 .

[0106] The second space is defined by the sidewalls and bottom wall of the groove 214. In other words, the second space is the interior space of the groove 214. Along the thickness direction, the second space is located on the side of the pressure relief zone 2111 away from the reinforcement portion 212. In other words, along the thickness direction, the first space 2124 and the second space are located on both sides of the pressure relief zone 2111.

[0107] By locating the pressure relief area 2111 between the first space 2124 and the second space, it is ensured that the pressure relief area 2111 is located within the range of the groove 214, and the groove 214 has a better thinning effect.

[0108] 8 , in some embodiments, the inner sidewall of the reinforcement portion 212 is inclined, forming an obtuse angle between the inner sidewall of the reinforcement portion 212 and the inner surface 2113. Thus, along the thickness direction, the first space 2124 gradually increases in size from the outer surface 2112 toward the inner surface 2113, facilitating the clearance of the electrode assembly 22.

[0109] In some embodiments, the outer wall of the reinforcement portion 212 is inclined, and an obtuse angle is formed between the outer wall of the reinforcement portion 212 and the inner surface 2113. In this way, the reinforcement portion 212 can be ensured to have a sufficient width while ensuring that the reinforcement portion 212 occupies a small portion of the accommodation space enclosed by the cover body 211 and the housing 23.

[0110] Referring to FIG. 8 , in some embodiments, the pressure relief area 2111 is provided with a pressure relief groove 213 .

[0111] The pressure relief groove 213 may be a groove 214 that is recessed from the surface of the pressure relief zone 2111 along the thickness direction of the cover body 211. The pressure relief groove 213 may be formed in a variety of ways, such as stamping, milling, and the like. The pressure relief groove 213 may be in a variety of shapes, which is not limited in this embodiment. For example, the pressure relief groove 213 may be a groove 214 that extends along a rectangular trajectory. The pressure relief groove 213 may also be a linear groove that extends along a curved trajectory. When the internal pressure of the battery cell 20 reaches the detonation pressure, the pressure relief zone 2111 may be opened with the pressure relief groove 213 as the boundary to release the pressure inside the battery cell 20.

[0112] By opening the pressure relief groove 213 in the pressure relief area 2111 and forming a thinned position on the pressure relief area 2111 , when the internal pressure of the battery cell 20 reaches the detonation pressure, the pressure relief area 2111 opens with the pressure relief groove 213 as the boundary to release the internal pressure.

[0113] Please refer to Figure 9, which is an enlarged view of position F in Figure 6. In some embodiments, the pressure relief groove 213 is a closed groove extending along a closed track connected end to end.

[0114] A closed track is a track connected at both ends, such as a rectangular track, an elliptical track, etc. Taking the example of forming the pressure relief groove 213 by milling, the cover body 211 can be processed along the closed track to form the pressure relief groove 213.

[0115] In this embodiment, the pressure relief groove 213 is a closed groove. After the pressure relief area 2111 is opened, the cover body 211 can form a larger opening at a position corresponding to the pressure relief area 2111, thereby improving the pressure relief efficiency.

[0116] 8 and 9 , in some embodiments, along the thickness direction, the reinforcement portion 212 and the pressure relief groove 213 are respectively located on both sides of the pressure relief area 2111 .

[0117] When the reinforcement portion 212 is provided on the inner surface 2113 of the cover body 211, the pressure relief groove 213 is provided on the side of the pressure relief area 2111 close to the outer surface 2112 of the cover body 211. When the reinforcement portion 212 is provided on the outer surface 2112 of the cover body 211, the pressure relief groove 213 is provided on the side of the pressure relief area 2111 close to the inner surface 2113 of the cover body 211.

[0118] By arranging the reinforcement portion 212 on the side of the pressure relief area 2111 away from the pressure relief groove 213 , processing and manufacturing are facilitated.

[0119] Referring to Figure 9 , in some embodiments, the pressure relief groove 213 includes a first groove segment 2131, a second groove segment 2132, a third groove segment 2133, and a fourth groove segment 2134, which are connected in sequence. Along a first direction, the first groove segment 2131 and the third groove segment 2133 are arranged opposite each other, and the maximum distance between the first groove segment 2131 and the third groove segment 2133 is a first distance. Along a second direction, the second groove segment 2132 and the fourth groove segment 2134 are arranged opposite each other, and the minimum distance between the second groove segment 2132 and the fourth groove segment 2134 is a second distance. The second distance is greater than the first distance, and the first direction, the second direction, and the thickness direction are perpendicular to each other.

[0120] The first slot segment 2131, the second slot segment 2132, the third slot segment 2133, and the fourth slot segment 2134 are slot segments located in four different directions of the pressure relief slot 213. In this embodiment, there is no particular limitation on the shapes of the first slot segment 2131, the second slot segment 2132, the third slot segment 2133, and the fourth slot segment 2134. For example, the first slot segment 2131, the second slot segment 2132, the third slot segment 2133, and the fourth slot segment 2134 can be straight slots or circular arc slots. If the first slot segment 2131, the second slot segment 2132, the third slot segment 2133, and the fourth slot segment 2134 are straight slots, the first slot segment 2131 and the third slot segment 2133 can be parallel or non-parallel, and the second slot segment 2132 and the fourth slot segment 2134 can be parallel or non-parallel.

[0121] If the first slot section 2131 is parallel to the third slot section 2133, the maximum distance between the first slot section 2131 and the third slot section 2133 is equal to the minimum distance. If the second slot section 2132 is parallel to the fourth slot section 2134, the maximum distance between the second slot section 2132 and the fourth slot section 2134 is equal to the minimum distance.

[0122] The second slot segment 2132 and the fourth slot segment 2134 are short sides of the pressure relief slot 213 , and the first slot segment 2131 and the third slot segment 2133 are long sides of the pressure relief slot 213 .

[0123] In this embodiment, the pressure relief zone 2111 defined by the pressure relief groove 213 has a large pressure relief area, a simple structure, and is easy to form and manufacture.

[0124] 9 , in some embodiments, the first slot segment 2131 and the third slot segment 2133 are straight slots; and / or the second slot segment 2132 and the fourth slot segment 2134 are arc slots.

[0125] The second slot segment 2132 and the fourth slot segment 2134 can bend in the same direction or in opposite directions. The second slot segment 2132 and the fourth slot segment 2134 can bend toward each other so that the center of the second slot segment 2132 and the center of the fourth slot segment 2134 are located outside the pressure relief zone 2111. The second slot segment 2132 and the fourth slot segment 2134 can also bend toward each other so that the center of the second slot segment 2132 and the center of the fourth slot segment 2134 are located within the pressure relief zone 2111.

[0126] For example, in Figure 9, the second slot segment 2132 and the fourth slot segment 2134 are bent in the direction away from each other, the first slot segment 2131 and the third slot segment 2133 are straight slots extending along the second direction of the cover body 211, the first slot segment 2131 and the third slot segment 2133 are both tangent to the second slot segment 2132, and the first slot segment 2131 and the third slot segment 2133 are both tangent to the fourth slot segment 2134. Along the second direction, the distance from the middle position of the second slot segment 2132 to the middle position of the fourth slot segment 2134 is the maximum distance between the second slot segment 2132 and the fourth slot segment 2134, and the length of the first slot segment 2131 is the minimum distance between the second slot segment 2132 and the fourth slot segment 2134.

[0127] In this embodiment, the second and fourth groove sections 2132, 2134 are arcuate grooves. The cover body 211 forms a weak point midway between the second and fourth groove sections 2132, 2134. This weak point is the initial opening position of the pressure relief zone 2111, allowing the pressure relief zone 2111 to open promptly when the detonation pressure within the battery cell 20 is reached. The first and third groove sections 2131, 2133 are both linear grooves extending along the second direction. These grooves are arranged parallel to each other. After the cover body 211 is split along the second and fourth groove sections 2132, 2134, it can more easily open along the first and third groove sections 2131, 2133, increasing the opening speed of the pressure relief zone 2111 and achieving rapid pressure relief.

[0128] Please refer to Figures 10, 11, and 12. Figure 10 is a schematic diagram of the structure of the end cap 21 provided in other embodiments of the present application. Figure 11 is a schematic top view of the end cap 21 provided in other embodiments of the present application. Figure 12 is a cross-sectional view taken at position GG in Figure 11. In other embodiments, the cover body 211 partially protrudes along the thickness direction to form a convex portion 2114, and the pressure relief groove 213 is disposed on the convex portion 2114.

[0129] The cover body 211 partially protrudes along the thickness direction of the cover body 211 to form a convex portion 2114, and a concave space will be formed on the side of the cover body 211 opposite to the convex portion 2114 in the thickness direction. On the one hand, it can accommodate the components inside the battery cell 20, which is beneficial to improving the energy density of the battery cell 20. On the other hand, it can improve the bending strength of the end cover 21 and improve the impact resistance of the end cover 21.

[0130] The present embodiment further provides a battery cell 20, which includes an electrode assembly 22, a housing 23, and the aforementioned end cap 21. The housing 23 has a receiving space with one end open for receiving the electrode assembly 22. The end cap 21 is connected to the housing 23 and closes the opening.

[0131] The embodiment of the present application further provides a battery 100 , which includes a housing 10 and the aforementioned battery cells 20 , wherein the battery cells 20 are accommodated in the housing 10 .

[0132] In some embodiments, the end cover 21 is disposed on a side of the battery cell 20 close to the bottom wall of the box body 10 .

[0133] The bottom wall of the box body 10 is a wall surface of the box body 10 opposite to the open end of the box body 10 .

[0134] By arranging the end cover 21 on a side of the battery cell 20 close to the bottom wall of the box body 10 , the battery cell 20 is placed upside down in the box body 10 .

[0135] An embodiment of the present application further provides an electrical device, which includes the above-mentioned battery 100, and the battery 100 is used to provide electrical energy.

[0136] According to some embodiments of the present application, please refer to Figures 4 to 8.

[0137] An embodiment of the present application provides an end cap 21, which includes a cap body 211 and a reinforcement portion 212. The cap body 211 has a pressure relief zone 2111, and the reinforcement portion 212 is protruding from one side of the cap body 211 in the thickness direction. The reinforcement portion 212 is arranged around the pressure relief zone 2111. The reinforcement portion 212 includes two first connecting segments 2121 and two second connecting segments 2122. Along the circumference of the pressure relief zone 2111, one first connecting segment 2121, one second connecting segment 2122, another first connecting segment 2121, and another second connecting segment 2122 are connected end to end to form a closed structure. The two first connecting segments 2121 are arranged opposite each other along a first direction, and the two second connecting segments 2122 are arranged opposite each other along a second direction. The first direction is perpendicular to the second direction. The dimension D1 of the first connecting segment 2121 in the first direction is greater than the dimension D2 of the second connecting segment 2122 in the second direction. The dimension D1 of the first connecting section 2121 in the first direction is 5% to 35% of the dimension L1 of the first connecting section 2121 in the second direction. The dimension D2 of the second connecting section 2122 in the second direction is 5% to 30% of the dimension L2 of the second connecting section 2122 in the first direction.

[0138] A groove 214 is provided at a position on the cover body 211 corresponding to the reinforcement portion 212. Along the thickness direction, the cover body 211 has an inner surface 2113 and an outer surface 2112 that face each other. The reinforcement portion 212 protrudes from the inner surface 2113, and the groove 214 is recessed from the outer surface 2112 toward the inner surface 2113. The inner sidewall of the reinforcement portion 212 defines a first space 2124, while the sidewalls and bottom wall of the groove 214 define a second space. Along the thickness direction, the first space 2124 and the second space are located on either side of the pressure relief zone 2111.

[0139] The pressure relief area 2111 of the end cap 21 is surrounded by a reinforcement portion 212, which strengthens the pressure relief area 2111 and improves its impact resistance. Thus, when the end cap 21 is subjected to an external impact, the reinforcement portion 212 can absorb the energy of the external impact, reducing the magnitude of the impact force transmitted to the pressure relief area 2111. This, to a certain extent, prevents the pressure relief area 2111 from being damaged by the external impact, thereby ensuring that the pressure relief area 2111 can perform its normal pressure relief function. This prevents the pressure relief area 2111 from opening when the internal pressure of the battery cell 20 has not reached the detonation pressure, thereby ensuring the normal operation of the battery cell 20. The two first connecting sections 2121 and the two second connecting sections 2122 are located in four different directions. The two first connecting sections 2121 and the two second connecting sections 2122 are connected to form a closed structure, which has strong strength and can effectively improve the impact resistance of the pressure relief area 2111. In addition, since the dimension D1 of the first connecting segment 2121 in the first direction is larger than the dimension D2 of the second connecting segment 2122 in the second direction, the dimension L2 of the second connecting segment 2122 in the first direction can be made smaller than the dimension L1 of the first connecting segment 2121 in the second direction, so that the reinforcement capacity of the first connecting segment 2121 and the reinforcement capacity of the second connecting segment 2122 are equivalent, thereby reducing the space occupied by the reinforcement part 212 and reducing material waste.

[0140] When the dimension D1 of the first connecting segment 2121 in the first direction is less than 5% of the dimension L1 of the first connecting segment 2121 in the second direction, the first connecting segment 2121 provides insufficient reinforcement, and when the end cap 21 is subjected to an external impact, the first connecting segment 2121 cannot effectively absorb the energy of the external impact. When the dimension D1 of the first connecting segment 2121 in the first direction is greater than 35% of the dimension L1 of the first connecting segment 2121 in the second direction, the first connecting segment 2121 occupies a large volume, and further increasing the dimension D1 of the first connecting segment 2121 in the first direction after it has already provided sufficient reinforcement results in material waste. When the dimension D2 of the second connecting segment 2122 in the second direction is less than 5% of the dimension L2 of the second connecting segment 2122 in the first direction, the second connecting segment 2122 provides insufficient reinforcement, and when the end cap 21 is subjected to an external impact, the second connecting segment 2122 cannot effectively absorb the energy of the external impact. When the dimension D2 of the second connecting segment 2122 in the second direction is greater than 30% of the dimension L2 of the second connecting segment 2122 in the first direction, the volume occupied by the second connecting segment 2122 is large, and after it has already had sufficient reinforcement effect, continuing to increase the dimension D2 of the second connecting segment 2122 in the second direction also causes waste of material.

[0141] By providing a groove 214 on the outer surface 2112 of the cover body 211, the groove 214 has a thinning effect, reducing the thickness of the pressure relief zone 2111. When the internal pressure of the battery cell 20 reaches the detonation pressure, the pressure relief zone 2111 is more easily opened by the internal pressure, thereby achieving pressure relief. The provision of the groove 214 makes the pressure relief zone 2111 more easily opened by internal pressure, and also more easily opened by external impact. Therefore, when the end cover 21 is subjected to an external impact, the reinforcement 212 can absorb the energy of the impact and reduce the magnitude of the impact force transmitted to the pressure relief zone 2111, thereby reducing the impact of the external impact on the pressure relief zone 2111, and to a certain extent preventing the pressure relief zone 2111 from being damaged by the external impact, ensuring that the normal pressure relief function can be achieved. By locating the pressure relief zone 2111 between the first space 2124 and the second space, the pressure relief zone 2111 is ensured to be within the range of the groove 214, and the groove 214 has a better thinning effect.

[0142] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. An end cap, wherein: include: a cover body having a pressure relief area; The reinforcement portion is protrudingly provided on one side of the cover body in the thickness direction, and the reinforcement portion is provided around the pressure relief area.

2. The end cap according to claim 1, wherein: The reinforcement portion includes two first connecting segments and two second connecting segments. Along the circumference of the pressure relief zone, one first connecting segment, one second connecting segment, another first connecting segment, and another second connecting segment are sequentially connected end to end to form a closed structure. The two first connecting segments are arranged opposite to each other along a first direction, and the two second connecting segments are arranged opposite to each other along a second direction, wherein the first direction is perpendicular to the second direction; The size of the first connecting segment in the first direction is greater than the size of the second connecting segment in the second direction.

3. The end cap according to claim 2, wherein: The size of the first connecting section in the first direction is 5% to 35% of the size of the first connecting section in the second direction.

4. The end cap according to claim 2 or 3, wherein: The size of the second connecting segment in the second direction is 5% to 30% of the size of the second connecting segment in the first direction.

5. The end cap according to any one of claims 2 to 4, wherein: The reinforcement portion includes at least one arc segment, and the first connecting segment and the second connecting segment are connected by the arc segment.

6. The end cap according to claim 1, wherein: A groove is provided at a position of the cover body corresponding to the reinforcement portion. Along the thickness direction, the cover body has an inner surface and an outer surface relative to each other. The reinforcement portion is protruded from the inner surface, and the groove is recessed from the outer surface toward the inner surface.

7. The end cap according to claim 6, wherein: The inner side wall of the reinforcement portion defines a first space, and the side wall and the bottom wall of the groove define a second space. Along the thickness direction, the first space and the second space are located on both sides of the pressure relief area.

8. The end cap according to claim 1, wherein: The pressure relief zone is provided with a pressure relief groove.

9. The end cap according to claim 8, wherein: The pressure relief groove is a closed groove extending along a closed track connected end to end.

10. The end cap according to claim 8 or 9, wherein: Along the thickness direction, the reinforcement portion and the pressure relief groove are respectively located on both sides of the pressure relief area.

11. The end cap according to any one of claims 8 to 10, wherein: The pressure relief groove comprises a first groove section, a second groove section, a third groove section and a fourth groove section connected in sequence; Along a first direction, the first slot segment and the third slot segment are arranged opposite to each other, and a maximum distance between the first slot segment and the third slot segment is a first distance; Along the second direction, the second slot segment and the fourth slot segment are arranged opposite to each other, and the minimum distance between the second slot segment and the fourth slot segment is a second distance; The second distance is greater than the first distance, and the first direction, the second direction, and the thickness direction are perpendicular to each other.

12. The end cap according to claim 11, wherein: The first slot segment and the third slot segment are straight slots; and / or The second slot segment and the fourth slot segment are arc slots.

13. The end cap according to any one of claims 1 to 12, wherein: The cover body partially protrudes along the thickness direction to form a convex portion, and the reinforcement portion is protruded on one side of the convex portion in the thickness direction.

14. A battery cell, wherein: include: electrode assembly; The housing has an opening at one end for accommodating the electrode assembly. ； The end cover according to any one of claims 1 to 13, wherein the end cover is connected to the shell and closes the opening.

15. A battery, wherein: include: Box; The battery cell according to claim 14, wherein the battery cell is housed in the box.

16. The battery according to claim 15, wherein: The end cover is arranged on one side of the battery cell close to the bottom wall of the box body.

17. An electrical device, wherein: The battery according to any one of claims 15 to 16 is used to provide electrical energy.

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