CN217788574U - End cover, battery monomer, battery and consumer - Google Patents

Abstract

The application provides an end cover, a battery cell, a battery and electrical equipment, and relates to the field of batteries. The end cover includes a cover body and a reinforcing part. The cover body has a pressure relief area, and the reinforcement part is protruded on one side of the cover body in the thickness direction, and the reinforcement part is arranged around the pressure relief area. A reinforcing part is arranged around the outside of the pressure relief area of the end cover, which strengthens the strength of the pressure relief area and improves the impact resistance of the pressure relief area. In this way, when the end cover is subjected to external impact, the reinforced part can absorb the energy of the external impact, reduce the magnitude of the impact force transmitted to the pressure relief area, and prevent the pressure relief area from being damaged by the external impact to a certain extent, thereby ensuring pressure relief. The pressure relief area can realize the normal pressure relief function, that is, prevent the pressure relief area from opening when the internal pressure of the battery cell does not reach the detonation pressure, so as to ensure the normal operation of the battery cell.

Description

End cover, battery cell, battery and electrical equipment

technical field

The present application relates to the field of batteries, in particular, to an end cover, a battery cell, a battery and electrical equipment.

Background technique

Batteries are widely used in the field of new energy, such as electric vehicles, new energy vehicles, etc. New energy vehicles and electric vehicles have become a new trend in the development of the automotive industry. The end cap of the battery cell is provided with a pressure relief structure for releasing the internal pressure when the internal pressure of the battery cell reaches the detonation pressure. However, in the scenario where the cells are inverted, the pressure relief structure is often opened in advance, resulting in failure to realize the normal pressure relief function.

Utility model content

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 is often opened in advance, resulting in the failure to realize the normal pressure relief function.

In the first aspect, the embodiment of the present application provides an end cover, the end cover includes a cover body and a reinforcement part, the cover body has a pressure relief area; the reinforcement part is protruded from the cover body in the thickness direction On one side, the reinforcement part is arranged around the pressure relief area.

In the above technical solution, a reinforcing part is arranged around the outside of the pressure relief area of the end cover, which strengthens the strength of the pressure relief area and improves the impact resistance of the pressure relief area. In this way, when the end cover is subjected to external impact, the reinforcement part can absorb the energy of the external impact, reduce the magnitude of the impact force transmitted to the pressure relief area, and to a certain extent avoid the damage of the pressure relief area due to external impact, thereby ensuring pressure relief. The pressure relief area can realize the normal pressure relief function, that is, prevent the pressure relief area from opening when the internal pressure of the battery cell does not reach the detonation pressure, so as to ensure the normal operation of the battery cell.

As an optional technical solution of the embodiment of the present application, the reinforcing part includes two first connecting sections and two second connecting sections, and along the circumferential direction of the pressure relief area, one of the first connecting sections, One of the second connecting section, the other of the first connecting section and the other of the second connecting section are sequentially connected end to end to form a closed structure; the two first connecting sections are arranged opposite to each other along the first direction, and the two said connecting sections The second connection section is 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 connection section in the first direction is larger than that of the second connection section in the first direction. Dimensions in the second direction.

In the above technical solution, the two first connecting sections and the two second connecting sections are respectively located in four different directions, and the two first connecting sections and the two second connecting sections are connected to form a closed structure, which has a strong The strength can effectively improve the impact resistance of the pressure relief area. In addition, since the size of the first connection section in the first direction is larger than the size of the second connection section in the second direction, the size of the second connection section in the first direction can be smaller than the size of the first connection section in the second direction. Dimensions, so that the reinforcing capacity of the first connecting section is equivalent to that of the second connecting section, reducing the space occupied by the reinforcing part and reducing material waste.

As an optional technical solution of the embodiment of the present application, the size of the first connection section in the first direction is 5% to 35% of the size of the first connection section in the second direction .

In the above technical solution, when the dimension of the first connecting section in the first direction is lower than 5% of the dimension of the first connecting section in the second direction, the reinforcing effect of the first connecting section is insufficient, and the end cover is subjected to external When impacting, it cannot effectively absorb the energy of external impact. When the size of the first connecting section in the first direction is greater than 35% of the size of the first connecting section in the second direction, the volume occupied by the first connecting section is relatively large, and after having sufficient reinforcement, continue Increasing the size of the first connecting section in the first direction also causes waste of material.

As an optional technical solution of the embodiment of the present application, the size of the second connection section in the second direction is 5% to 30% of the size of the second connection section in the first direction .

In the above technical solution, when the size of the second connecting section in the second direction is lower than 5% of the size of the second connecting section in the first direction, the reinforcing effect of the second connecting section is insufficient, and the end cover is subjected to external When impacting, it cannot effectively absorb the energy of external impact. When the size of the second connection section in the second direction is greater than 30% of the size of the second connection section in the first direction, the volume occupied by the second connection section is relatively large, and after having sufficient reinforcement, continue Increasing the size of the second connecting section in the second direction also causes waste of material.

As an optional technical solution of the embodiment of the present application, the reinforcing part includes at least one arc segment, and one of the first connecting segments and one of the second connecting segments are connected through one of the arc segments.

In the above technical solution, by setting the arc segment to connect the first connecting segment and the second connecting segment, the stress concentration at the corner can be reduced and the stress can be optimized.

As an optional technical solution of the embodiment of the present application, the cover body is provided with a groove at a position corresponding to the reinforcing part, and along the thickness direction, the cover body has an opposite inner surface and an outer surface, The reinforcement part is protruded on the inner surface, and the groove is recessed from the outer surface toward the inner surface.

In the above technical solution, by providing grooves on the outer surface of the cover body, the grooves play a role of thinning, so that the thickness of the pressure relief area is reduced. When the internal pressure of the battery cell reaches the detonation pressure, the pressure relief area is more likely to be opened by the internal pressure, thereby achieving pressure relief. The setting of the groove makes the pressure relief area easier to be washed away by internal pressure, and also easier to be washed away by external impact. Therefore, when the end cover is subjected to external impact, the reinforced part can absorb the impact energy and reduce the impact force transmitted to the pressure relief area, so as to reduce the impact of external impact on the pressure relief area, and to a certain extent avoid the pressure relief area due to If it is damaged by external impact, it can ensure the normal pressure relief function, that is, prevent the pressure relief area from opening when the internal pressure of the battery cell does not reach the detonation pressure, so as to ensure the normal operation of the battery cell.

As an optional technical solution of the embodiment of the present application, the inner side wall of the reinforcing part defines a first space, the side wall and the bottom wall of the groove define a second space, and along the thickness direction, the The first space and the second space are located on two sides of the pressure relief area.

In the above technical solution, by making the pressure relief area located between the first space and the second space, it is ensured that the pressure relief area is located within the scope of the groove, and the thinning effect of the groove is better.

As an optional technical solution of the embodiment of the present application, the pressure relief area is provided with a pressure relief groove.

In the above technical solution, by providing a pressure relief groove in the pressure relief area, a thinning position is formed on the pressure relief area, and when the internal pressure of the battery cell reaches the detonation pressure, it is convenient for the pressure relief area to open with the pressure relief groove as the boundary. to relieve internal pressure.

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

In the above technical solution, by setting the pressure relief groove as a closed groove extending along the closed trajectory 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, improving the pressure relief. pressure efficiency.

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

In the above technical solution, by arranging the reinforcing part on the side of the pressure relief area away from the pressure relief groove, processing and manufacturing are facilitated.

As an optional technical solution of the 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 A groove segment is arranged opposite to the third groove segment, and the maximum distance between the first groove segment and the third groove segment is a first distance; along the second direction, the second groove segment and the The fourth slot section is relatively arranged, and the minimum distance between the second slot section and the fourth slot section is a second distance; the second distance is greater than the first distance, and the first direction, the The second direction is perpendicular to the thickness direction two by two.

In the above technical solution, the weak area formed on the pressure relief area by the boundaries of the first groove section, the second groove section, the third groove section and the fourth groove section is relatively large, which is easy to be internally blasted when the inside of the battery cell reaches the detonation pressure. It is punched out by pressure, and has a simple structure and is easy to form and manufacture.

As an optional technical solution of the embodiment of the present application, the first groove segment and the third groove segment are linear grooves; and/or the second groove segment and the fourth groove segment are arc grooves .

In the above technical solution, the second groove section and the fourth groove section are arc grooves, and the cover body forms a weak position in the middle of the second groove section and the fourth groove section, and the weak position is the lowest point of the pressure relief area. Open the position first, so that the pressure relief area can be opened in time when the inside of the battery cell reaches the detonation pressure. The first groove section and the third groove section are linear grooves extending along the width direction of the cover body, so that the first groove section and the third groove section are arranged in parallel, and the cover body is split along the second groove section and the fourth groove section Finally, it can be opened more easily along the first groove section and the third groove section, increasing the opening rate of the pressure relief area, and realizing rapid pressure relief.

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.

In the above technical solution, a part of the cover body protrudes along the thickness direction of the cover body to form a convex part, and the side of the cover body opposite to the convex part in the thickness direction will form a corresponding recessed space. On the one hand, it can accommodate the inside of the battery cell. The components are conducive 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.

In the second aspect, the embodiment of the present application also provides a battery cell, the battery cell includes an electrode assembly, a casing, and the above-mentioned end cap; the casing has an accommodation space with one end open, and the accommodation space is used for for accommodating the electrode assembly; the end cap is connected to the casing and closes the opening.

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

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

In the above technical solution, by disposing the end cap on the side of the battery cell close to the bottom wall of the box, the battery cell is placed upside down in the box.

In a fourth aspect, an embodiment of the present application further provides an electric device, the electric device includes the above-mentioned battery, and the battery is used to provide electric energy.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the accompanying drawings used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, so It should be regarded as a limitation on the scope, and those skilled in the art can also obtain other related drawings based on these drawings without creative work.

Fig. 1 is a schematic structural diagram of a vehicle provided by some embodiments of the present application;

Figure 2 is an exploded view of a battery provided in some embodiments of the present application;

Fig. 3 is a schematic structural diagram of a battery cell provided by some embodiments of the present application;

Fig. 4 is a schematic structural diagram of an end cap provided in some embodiments of the present application;

Fig. 5 is a schematic bottom view of an end cap provided in some embodiments of the present application;

Fig. 6 is a schematic top view of an end cap provided in some embodiments of the present application;

Fig. 7 is the sectional view of C-C position in Fig. 6;

Fig. 8 is an enlarged view of position E in Fig. 7;

Fig. 9 is an enlarged view of position F in Fig. 6;

Fig. 10 is a schematic structural view of end caps provided in other embodiments of the present application;

Fig. 11 is a schematic top view of end caps provided in other embodiments of the present application;

Fig. 12 is a cross-sectional view at position G-G in Fig. 11 .

Icons: 10-box; 11-first part; 12-second part; 20-battery unit; 21-end cover; 211-cover body; 2111-pressure relief area; 2112-outer surface; 2113-inner surface; 2114-convex part; 212-reinforcing part; 2121-first connecting section; 2122-second connecting section; 2123-arc section; 2124-first space; 213-pressure relief groove; 2131-first groove section; -Second slot; 2133-third slot; 2134-fourth slot; 214-groove; 22-electrode assembly; 23-shell; 100-battery; 200-controller; 300-motor; 1000- vehicle.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are the Claim some of the examples, not all of them. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of this application.

Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by those skilled in the technical field of this application; the terms used in this application in the description of the application are only to describe specific implementations The purpose of the example is not intended to limit the present application; the terms "comprising" and "having" and any variations thereof in the description and claims of the present application and the description of the above drawings are intended to cover non-exclusive inclusion. The terms "first", "second" and the like in the description and claims of the present application or the above drawings are used to distinguish different objects, rather than to describe a specific sequence or primary-subordinate relationship.

Reference in this application to an "embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The occurrences of this phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.

In the description of this application, it should be noted that, unless otherwise clearly stipulated and limited, the terms "installation", "connection", "connection" and "attachment" should be understood in a broad sense, for example, it may be a fixed connection, It can also be detachably connected or integrally connected; it can be directly connected or indirectly connected through an intermediary, and it can be internal communication between two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in this application according to specific situations.

The term "and/or" in this application is only an association relationship describing associated objects, which means that there may be three relationships, for example, A and/or B, which may mean: A exists alone, A and B exist simultaneously, and A and B exist alone. There are three cases of B. In addition, the character "/" in this application generally indicates that the contextual objects are an "or" relationship.

In the embodiments of the present 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 the various components in the embodiments of the application shown in the drawings, as well as the overall thickness, length and width of the integrated device, are for illustrative purposes only, and should not constitute any limitation to the application .

"Plurality" in this application refers to two or more (including two).

In this application, the 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. The embodiment of the present application does not limit this. The battery cell can be in the form of a cylinder, a flat body, a cuboid or other shapes, which is not limited in this embodiment of the present application. Battery cells are generally divided into three types according to packaging methods: cylindrical battery cells, square battery cells and pouch battery cells, which are not limited in this embodiment of the present application.

The battery mentioned in the embodiments of the present application refers to a single physical module including 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, and the like. Batteries generally include a case for enclosing one or more battery cells. The box can prevent liquid or other foreign objects from affecting the charging or discharging of the battery cells.

The battery cell includes an electrode assembly and an electrolyte, and the electrode assembly is composed of a positive electrode sheet, a negative electrode sheet, and a separator. A battery cell works primarily by moving metal ions between the positive and negative plates. The positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer, the positive electrode active material layer is coated on the surface of the positive electrode current collector, and the positive electrode current collector that is not coated with the positive electrode active material layer protrudes from the positive electrode collector that has been coated with the positive electrode active material layer , the positive electrode current collector that is not coated with the positive electrode active material layer is used as the positive electrode ear. Taking a lithium-ion battery as an example, the material of the positive electrode current collector can be aluminum, and the positive electrode active material can be lithium cobaltate, lithium iron phosphate, ternary lithium or lithium manganate. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer, the negative electrode active material layer is coated on the surface of the negative electrode current collector, and the negative electrode current collector that is not coated with the negative electrode active material layer protrudes from the negative electrode collector that has been coated with the negative electrode active material layer , the negative electrode current collector that is not coated with the negative electrode active material layer is used as the negative electrode ear. The material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon or silicon. In order to ensure that a large current is passed without fusing, the number of positive tabs is multiple and stacked together, and the number of negative tabs is multiple and stacked together. The material of the isolation film may be PP (polypropylene, polypropylene) or PE (polyethylene, polyethylene). In addition, the electrode assembly may be a wound structure or a laminated structure, which is not limited in the embodiment of the present application.

The development of battery technology should consider many design factors at the same time, such as energy density, cycle life, discharge capacity, charge and discharge rate and other performance parameters. In addition, the safety of the battery also needs to be considered.

For the battery cell, in order to ensure the safety of the battery cell, a pressure relief structure can be installed on the end cover of the battery cell. When the internal pressure of the battery cell reaches the detonation pressure, the pressure relief structure opens to discharge the battery. The pressure inside the cell to reduce the risk of battery cell explosion and fire.

The inventor noticed that in the scenario where the battery cell is inverted, the pressure relief structure is often opened in advance, resulting in failure to realize the normal pressure relief function.

The inventor further researched and found that in the scenario where the battery cell is inverted, the end cap is more susceptible to external impact, and the external impact force is easily transmitted to the position where the pressure relief structure is located, thereby causing the pressure relief structure to open in advance, resulting in failure to achieve normal pressure relief Function.

In view of this, the embodiment of the present application provides an end cover, including a cover body and a reinforcement part, the cover body has a pressure relief area, the reinforcement part protrudes from one side of the cover body in the thickness direction, and the reinforcement part surrounds the pressure relief area.

A reinforcing part is arranged around the outside of the pressure relief area of the end cover, which strengthens the strength of the pressure relief area and improves the impact resistance of the pressure relief area. In this way, when the end cover is subjected to external impact, the reinforcement part can absorb the energy of the external impact, reduce the magnitude of the impact force transmitted to the pressure relief area, and to a certain extent avoid the damage of the pressure relief area due to external impact, thereby ensuring pressure relief. The pressure relief area can realize the normal pressure relief function, that is, prevent the pressure relief area from opening when the internal pressure of the battery cell does not reach the detonation pressure, so as to ensure the normal operation of the battery cell.

The technical solutions described in the embodiments of the present application are applicable to batteries and electric devices using batteries.

Electrical devices can be vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys and power tools, etc. Spacecraft include airplanes, rockets, space shuttles and spaceships, etc.; electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric boat toys and electric airplane toys, etc.; 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, etc. The embodiment of the present application does not impose special limitations on the above electric equipment.

For convenience of description, the following embodiments take the vehicle 1000 as an example for illustration.

Please refer to FIG. 1 , which is a schematic structural diagram of a vehicle 1000 provided by some embodiments of the present application. The vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle. The interior of the vehicle 1000 is provided with a battery 100 , and the battery 100 may be provided at the bottom, head or tail of the vehicle 1000 . The battery 100 can be used for power supply of the vehicle 1000 , for example, the battery 100 can be used as an operating power source of the vehicle 1000 . The vehicle 1000 may further 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, for starting, navigating and running the vehicle 1000 .

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

Please refer to FIG. 2 , which is an exploded view of a battery 100 provided by some embodiments of the present application. The battery 100 includes a case 10 and battery cells 20 housed in the case 10 . Wherein, the box body 10 is used to provide accommodating space for the battery cells 20 , and the box body 10 may adopt various structures. In some embodiments, the box body 10 may include a first part 11 and a second part 12, the first part 11 and the second part 12 cover each other, the first part 11 and the second part 12 jointly define a of accommodation space. The second part 12 can be a hollow structure with one end open, the first part 11 can be a plate-like structure, and the first part 11 covers the opening side of the second part 12, so that the first part 11 and the second part 12 jointly define an accommodation space ; The first part 11 and the second part 12 can also be hollow structures with one side opening, and the opening side of the first part 11 is covered by the opening side of the second part 12 . Of course, the box body 10 formed by the first part 11 and the second part 12 can be in various shapes, such as a cylinder, a cuboid and the like.

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 parallel. The mixed connection means that the multiple battery cells 20 are connected in series and in parallel. A plurality of battery cells 20 can be directly connected in series, in parallel or mixed together, and then the whole composed of a plurality of battery cells 20 is housed in the box 10; of course, the battery 100 can also be a plurality of battery cells 20 The battery modules are firstly connected in series or parallel or in combination, and then multiple battery modules are connected in series or in parallel or in combination to form a whole, which is accommodated in the case 10 . The battery 100 may also include other structures, for example, the battery 100 may also include a bus component for realizing electrical connection between multiple battery cells 20 .

Wherein, 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 in the form of a cylinder, a flat body, a cuboid or other shapes.

Please refer to FIG. 3 , which is a schematic diagram of an exploded structure of a battery cell 20 provided in some embodiments of the present application. The battery cell 20 refers to the smallest unit constituting the battery 100 . As shown in FIG. 3 , the battery cell 20 includes an end cap 21 , an electrode assembly 22 , a casing 23 and other functional components.

The end cap 21 refers to a component that covers the opening of the casing 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 fit the housing 23 . Optionally, the end cap 21 can be made of a material (such as aluminum alloy) with a certain hardness and strength, so that the end cap 21 is not easy to deform when being squeezed and collided, so that the battery cell 20 can have a higher Structural strength and safety performance can also be improved. Functional components such as electrode terminals (not shown in the figure) may be provided on the end cap 21 . The electrode terminals can be used for electrical connection with the electrode assembly 22 for outputting or inputting electric energy of the battery cell 20 . The material of the end cap 21 can also be various, for example, copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which is not particularly limited in this embodiment of the present application. In some embodiments, an insulator can be provided inside the end cover 21 , and the insulator can be used to isolate the electrical connection components in the housing 23 from the end cover 21 to reduce the risk of short circuit. Exemplarily, the insulating member may be plastic, rubber or the like.

The casing 23 is a component used to cooperate with the end cap 21 to form the internal environment of the battery cell 20 , wherein the formed internal environment can be used to accommodate the electrode assembly 22 , electrolyte and other components. The housing 23 and the end cover 21 can be independent components, and an opening can be provided on the housing 23 , and the internal environment of the battery cell 20 can be formed by making the end cover 21 cover the opening at the opening. Without limitation, the end cover 21 and the housing 23 can also be integrated. Specifically, the end cover 21 and the housing 23 can form a common connection surface before other components are inserted into the housing. When the inside of the housing 23 needs to be encapsulated , then make the end cover 21 cover the housing 23. The housing 23 can be in various shapes and sizes, such as cuboid, cylinder, hexagonal prism and so on. Specifically, the shape of the casing 23 may be determined according to the specific shape and size of the electrode assembly 22 . The housing 23 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which is not particularly limited in this embodiment of the present application.

The electrode assembly 22 is a part where electrochemical reactions occur in the battery cell 20 . One or more electrode assemblies 22 may be contained within the case 23 . The electrode assembly 22 is mainly formed by winding or laminating the positive electrode sheet and the negative electrode sheet, and usually a separator is provided between the positive electrode sheet and the negative electrode sheet. The parts of the positive electrode sheet and the negative electrode sheet with the active material constitute the main body of the electrode assembly 22 , and the parts of the positive electrode sheet and the negative electrode sheet without the active material respectively constitute tabs. The positive pole tab and the negative pole tab can be located at one end of the main body together or at two ends of the main body respectively. During the charging and discharging process of the battery 100 , the positive electrode active material and the negative electrode active material react with the electrolyte, and the tabs are connected to the electrode terminals to form a current loop.

Please refer to FIG. 4 and FIG. 5 . FIG. 4 is a schematic structural diagram of an end cap 21 provided in some embodiments of the present application. FIG. 5 is a schematic bottom view of the end cap 21 provided by some embodiments of the present application. The embodiment of the present application provides an end cover 21 , and the end cover 21 includes a cover body 211 and a reinforcement part 212 . The cover body 211 has a pressure relief area 2111 , a reinforcement portion 212 protrudes from one side of the cover body 211 in the thickness direction, and the reinforcement portion 212 is disposed around the pressure relief area 2111 .

The cover body 211 is the main structure of the end cover 21 and is mainly used to close 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, when the opening of the housing 23 is rectangular, the shape of the cover body 211 is also rectangular. When the opening of the housing 23 is circular, the shape of the cover body 211 is also circular.

The pressure relief area 2111 is the area on the cover body 211 that realizes the pressure relief function. For example, the pressure relief area 2111 may be an area where a rupture disk is welded on the end cover 21 . As another example, a pressure relief groove 213 is opened on the end cover 21 , and the pressure relief area 2111 may include an area inside the pressure relief groove 213 and a partial area outside the pressure relief groove 213).

The reinforcing portion 212 is a protruding structure protruding from one side of the cover body 211 in the thickness direction (direction D as shown in FIG. 8 ) and surrounding the pressure relief area 2111 . The reinforcement part 212 can be disposed on the surface of the cover body 211 facing the inside of the housing 23 , or can be disposed on the surface of the cover body 211 facing away from the housing 23 . Taking the cover body 211 as a rectangular plate structure as an example, the cover body 211 has an opposite inner surface 2113 and an outer surface 2112 in the thickness direction, the inner surface 2113 of the cover body 211 faces the inside of the housing 23, and the outer surface 2112 of the cover body 211 deviates from The casing 23 is provided, and the reinforcing part 212 can be provided on the inner surface 2113 of the cover body 211 , or can be provided on the outer surface 2112 of the cover body 211 .

Reinforcing portion 212 may be of various shapes. For example, the reinforcing part 212 is formed into a racetrack shape, and the pressure relief area 2111 is a part surrounded by the inner circle of the racetrack shape on the cover body 211 . In another example, the reinforcement part 212 is surrounded by a rectangle. The pressure relief area 2111 is a rectangular circled part on the cover body 211 . For another example, if the reinforcement part 212 is a U-shaped protrusion extending along a U-shaped track, the pressure relief area 2111 is a part surrounded by the U-shaped protrusion.

The outer side of the pressure relief area 2111 of the end cover 21 is provided with a reinforcing part 212 , which strengthens the strength of the pressure relief area 2111 and improves the impact resistance of the pressure relief area 2111 . In this way, when the end cover 21 is subjected to an external impact, the reinforcing part 212 can absorb the energy of the external impact, reduce the impact force transmitted to the pressure relief area 2111, and avoid the damage of the pressure relief area 2111 due to the external impact to a certain extent. Furthermore, it is ensured that the pressure relief area 2111 can realize the normal pressure relief function, that is, to prevent the pressure relief area 2111 from opening when the internal pressure of the battery cell 20 does not reach the detonation pressure, so as to ensure the normal operation of the battery cell 20 .

Referring to FIG. 5 , in some embodiments, the reinforcing part 212 includes two first connecting sections 2121 and two second connecting sections 2122 . Along the circumferential direction of the pressure relief area 2111 , a first connecting section 2121 , a second connecting section 2122 , another first connecting section 2121 and another second connecting section 2122 are sequentially connected end to end to form a closed structure. The two first connecting sections 2121 are arranged opposite to each other along a first direction, the two second connecting sections 2122 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 section 2121 in the first direction is greater than the size of the second connecting section 2122 in the second direction.

The two first connecting sections 2121 and the two second connecting sections 2122 are parts of the reinforcing part 212 located in four different directions respectively. In this embodiment, the two first connecting sections 2121 and the two second connecting sections 2122 are straight protrusions extending along a straight track. "A first connection section 2121, a second connection section 2122, another first connection section 2121 and another second connection section 2122 are sequentially connected end to end to form a closed structure" includes both the tail end of a first connection section 2121 and a The head end of the second connection section 2122 is directly connected, and the tail end of one first connection section 2121 is indirectly connected to the head end of another second connection section 2122 through an intermediate structure. Likewise, the tail end of one second connection section 2122 may be directly connected to the head end of another first connection section 2121, or may be indirectly connected through an intermediate structure.

Since the first connecting section 2121 and the second connecting section 2122 are linear projections, "the two first connecting sections 2121 are relatively arranged along the first direction (direction A as shown in Fig. 5), and the two second connecting sections 2122 are relatively arranged along the second direction (direction B as shown in FIG. 5 )" can also be understood as two first connecting sections 2121 are arranged in parallel in the first direction, and two second connecting sections 2122 are arranged in parallel in the second direction .

In this embodiment, please refer to FIG. 5 , the length of the first connecting section 2121 in the second direction (L1 shown in FIG. 5 ) is greater than the length of the second connecting section 2122 in the first direction (as shown in FIG. L2 shown in 5). In this way, the side where the second connecting section 2122 is located is the short side of the reinforcing part 212 , and the side where the second connecting section 2122 is located is the long side of the reinforcing part 212 . Because the two corners of the short side are closer, it can play a strengthening role. If the size of the first connection section 2121 in the first direction (D1 as shown in Figure 5) is equal to the size of the second connection section 2122 in the second direction (D2 as shown in Figure 5), then the reinforcing part 212 is stronger on the short side and weaker on the long side.

In this embodiment, by making the dimension D1 of the first connecting section 2121 in the first direction larger than the dimension D2 of the second connecting section 2122 in the second direction, the strengthening degree of the reinforcing part 212 on the short side is the same as that of the reinforcing part. 212 is equally reinforced on the long side.

The two first connecting sections 2121 and the two second connecting sections 2122 are respectively located in four different directions, and the two first connecting sections 2121 and the two second connecting sections 2122 are connected to form a closed structure with strong strength. The impact resistance of the pressure relief area 2111 can be effectively improved. In addition, since the dimension D1 of the first connecting section 2121 in the first direction is larger than the dimension D2 of the second connecting section 2122 in the second direction, the dimension L2 of the second connecting section 2122 in the first direction can be smaller than that of the first connecting section 2122. The dimension L1 of the segment 2121 in the second direction is such that the reinforcing capacity of the first connecting segment 2121 is equivalent to that of the second connecting segment 2122 , reducing the space occupied by the reinforcing part 212 and reducing material waste.

In some embodiments, the dimension D1 of the first connection section 2121 in the first direction is 5%-35% of the dimension L1 of the first connection section 2121 in the second direction.

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

When the dimension D1 of the first connecting section 2121 in the first direction is lower than 5% of the dimension L1 of the first connecting section 2121 in the second direction, the reinforcing effect of the first connecting section 2121 is insufficient, and the end cover 21 is subjected to external When impacting, it cannot effectively absorb the energy of external impact. When the dimension D1 of the first connecting section 2121 in the first direction is greater than 35% of the dimension L1 of the first connecting section 2121 in the second direction, the volume occupied by the first connecting section 2121 is large, and there is enough After the reinforcing effect, continuing to increase the dimension D1 of the first connecting section 2121 in the first direction also results in waste of materials.

In some embodiments, the dimension D2 of the second connecting section 2122 in the second direction is 5%-30% of the dimension L2 of the second connecting section 2122 in the first direction.

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

When the dimension D2 of the second connecting section 2122 in the second direction is lower 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 cover 21 is subjected to external When impacting, it cannot effectively absorb the energy of external impact. 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 there is enough After the reinforcing effect, continuing to increase the dimension D2 of the second connecting section 2122 in the second direction also results in waste of materials.

Referring to FIG. 5 , in some embodiments, the reinforcing part 212 includes at least one arc segment 2123 , and a first connecting segment 2121 and a second connecting segment 2122 are connected by an arc segment 2123 .

The arc segment 2123 is a convex structure extending along the arc track. The reinforcing part 212 may have one arc segment 2123 , two arc segments 2123 , three arc segments 2123 or four arc segments 2123 . The first connecting section 2121 and the second connecting section 2122 are indirectly connected by an arc section 2123 to realize arc transition.

By setting the arc segment 2123 to connect the first connecting segment 2121 and the second connecting segment 2122, the stress concentration at the corner can be reduced and the stress can be optimized.

Please refer to FIG. 6 , FIG. 7 and FIG. 8 . FIG. 6 is a schematic top view of the end cap 21 provided by some embodiments of the present application. Fig. 7 is a cross-sectional view at position C-C in Fig. 6 . FIG. 8 is an enlarged view of position E in FIG. 7 . In some embodiments, a groove 214 is provided at a position corresponding to the reinforcement part 212 on the cover body 211 . The cover body 211 has opposing inner and outer surfaces 2113 and 2112 in a thickness direction. The reinforcing 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 groove 214 is provided at the position corresponding to the reinforcement portion 212 on the cover body 211 ” means that along the thickness direction, the projection of the outline of the groove 214 falls within the projection range of the reinforcement portion 212 .

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

The groove 214 refers to a groove-shaped structure penetrating through the outer surface 2112 of the cover body 211 and extending along a direction 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.

By opening the groove 214 on the outer surface 2112 of the cover body 211 , the groove 214 plays a role of thinning, so that the thickness of the pressure relief area 2111 is reduced. When the internal pressure of the battery cell 20 reaches the detonation pressure, the pressure relief area 2111 is more likely to be opened by the internal pressure, thereby achieving pressure relief. The arrangement of the groove 214 makes the pressure relief area 2111 more likely to be washed away by the internal pressure, and also easier to be washed away by the external impact. Therefore, when the end cover 21 is subjected to an external impact, the reinforcement part 212 can absorb the energy of the impact and reduce the magnitude of the impact force transmitted to the pressure relief area 2111, so as to reduce the impact of the external impact on the pressure relief area 2111, and to a certain extent avoid The pressure relief area 2111 is damaged due to external impact, ensuring that the normal pressure relief function can be realized.

Referring to FIG. 8 , in some embodiments, the inner sidewall of the reinforcement part 212 defines a first space 2124 , and the sidewall 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 both sides of the pressure relief area 2111 .

The first space 2124 is a space defined by the inner wall of the reinforcement part 212 , and along the thickness direction, the first space 2124 is located on a side of the pressure relief area 2111 close to the reinforcement part 212 .

The second space is the space defined by the sidewall and the bottom wall of the groove 214 , in other words, the second space is the inner space of the groove 214 . Along the thickness direction, the second space is located on a side of the pressure relief area 2111 away from the reinforcing portion 212 . That is, along the thickness direction, the first space 2124 and the second space are located on both sides of the pressure relief area 2111 .

By making the pressure relief area 2111 located 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 thinning effect of the groove 214 is better.

Referring to FIG. 8 , in some embodiments, the inner sidewall of the reinforcing part 212 is inclined, and an obtuse angle is formed between the inner sidewall of the reinforcing part 212 and the inner surface 2113 . In this way, along the thickness direction, the first space 2124 gradually increases in the direction from the outer surface 2112 to the inner surface 2113 , which is beneficial for avoiding the electrode assembly 22 .

In some embodiments, the outer sidewall of the reinforcement part 212 is inclined, and an obtuse angle is formed between the outer sidewall of the reinforcement part 212 and the inner surface 2113 . In this way, under the condition that the width of the reinforcement part 212 is sufficient, it can be ensured that the reinforcement part 212 occupies less space enclosed by the cover body 211 and the casing 23 .

Please refer to FIG. 8 , in some embodiments, the pressure relief area 2111 is provided with a pressure relief groove 213 .

The pressure relief groove 213 may be a groove 214 depressed from the surface of the pressure relief area 2111 along the thickness direction of the cover body 211 . The pressure relief groove 213 can be formed in various ways, such as stamping, milling and so on. The pressure relief groove 213 can be in various shapes, which is not limited in this embodiment. For example, the relief groove 213 may be a groove 214 extending along a rectangular trajectory. The pressure relief groove 213 can also be a linear groove extending along the bending track. When the internal pressure of the battery cell 20 reaches the detonation pressure, the pressure relief area 2111 can be opened with the pressure relief groove 213 as the boundary to release the battery cell. 20 internal pressure.

By opening the pressure relief groove 213 in the pressure relief area 2111, a thinning position is formed on the pressure relief area 2111, and when the internal pressure of the battery cell 20 reaches the detonation pressure, the pressure relief area 2111 is opened with the pressure relief groove 213 as the boundary, to relieve internal pressure.

Please refer to FIG. 9 , which is an enlarged view of position F in FIG. 6 . In some embodiments, the relief slot 213 is a closed slot extending along an end-to-end closed track.

Closed trajectories are trajectories whose ends are connected, such as rectangular trajectories, elliptical trajectories, etc. Taking forming the pressure relief groove 213 by milling as an example, the cover body 211 may be processed along a closed track to form the pressure relief groove 213 .

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 to improve the pressure relief efficiency.

Please refer to FIG. 8 and FIG. 9 , in some embodiments, along the thickness direction, the reinforcing portion 212 and the pressure relief groove 213 are respectively located on two sides of the pressure relief area 2111 .

When the reinforcing portion 212 is disposed on the inner surface 2113 of the cover body 211 , the pressure relief groove 213 is disposed on a side of the pressure relief area 2111 close to the outer surface 2112 of the cover body 211 . And when the reinforcing portion 212 is disposed on the outer surface 2112 of the cover body 211 , the pressure relief groove 213 is disposed on a side of the pressure relief area 2111 close to the inner surface 2113 of the cover body 211 .

By arranging the reinforcing part 212 on the side of the pressure relief area 2111 away from the pressure relief groove 213 , it is convenient for processing and manufacturing.

Referring to FIG. 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 connected in sequence. Along the first direction, the first slot section 2131 and the third slot section 2133 are arranged oppositely, and the maximum distance between the first slot section 2131 and the third slot section 2133 is the first distance. Along the second direction, the second slot segment 2132 and the fourth slot segment 2134 are arranged oppositely, and the minimum distance between the second slot segment 2132 and the fourth slot segment 2134 is the 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.

The first slot section 2131 , the second slot section 2132 , the third slot section 2133 and the fourth slot section 2134 are slot sections where the pressure relief slot 213 is located in four different orientations. In this embodiment, there is no special limitation on the shapes of the first slot section 2131 , the second slot section 2132 , the third slot section 2133 and the fourth slot section 2134 . For example, the first slot segment 2131 , the second slot segment 2132 , the third slot segment 2133 and the fourth slot segment 2134 may be linear slots or arc slots. If the first groove section 2131, the second groove section 2132, the third groove section 2133 and the fourth groove section 2134 are linear grooves, the first groove section 2131 and the third groove section 2133 can be parallel or non-parallel, and the second groove section Segment 2132 and fourth slot segment 2134 may or may not be parallel.

If the first slot section 2131 and the third slot section 2133 are arranged in parallel, the maximum distance and the minimum distance between the first slot section 2131 and the third slot section 2133 are equal. If the second slot section 2132 and the fourth slot section 2134 are arranged in parallel, the maximum distance and the minimum distance between the second slot section 2132 and the fourth slot section 2134 are equal.

The second groove section 2132 and the fourth groove section 2134 are short sides of the pressure relief groove 213 , and the first groove section 2131 and the third groove section 2133 are long sides of the pressure relief groove 213 .

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

Referring to FIG. 9 , in some embodiments, the first groove segment 2131 and the third groove segment 2133 are linear grooves; and/or the second groove segment 2132 and the fourth groove segment 2134 are arc grooves.

The second groove segment 2132 and the fourth groove segment 2134 may bend in the same direction, or bend in opposite directions. The second groove segment 2132 and the fourth groove segment 2134 can be bent toward each other, so that the center of the circle of the second groove segment 2132 and the circle center of the fourth groove segment 2134 are located outside the pressure relief area 2111 . The second groove segment 2132 and the fourth groove segment 2134 can also be curved in a direction away from each other, and the circle centers of the second groove segment 2132 and the fourth groove segment 2134 are located in the pressure relief area 2111 .

Exemplarily, in FIG. 9 , the second groove segment 2132 and the fourth groove segment 2134 are bent away from each other, and the first groove segment 2131 and the third groove segment 2133 are straight lines extending along the second direction of the cover body 211 The groove, the first groove segment 2131 and the third groove segment 2133 are both tangent to the second groove segment 2132, and the first groove segment 2131 and the third groove segment 2133 are both tangent to the fourth groove segment 2134, along the second direction, The distance from the middle position of the second groove segment 2132 to the middle position of the fourth groove segment 2134 is the maximum distance between the second groove segment 2132 and the fourth groove segment 2134, and the length of the first groove segment 2131 is the second groove Minimum distance between segment 2132 and fourth slot segment 2134 .

In this embodiment, the second groove segment 2132 and the fourth groove segment 2134 are circular arc grooves, and the cover body 211 forms a weak position at the middle position of the second groove segment 2132 and the middle position of the fourth groove segment 2134, and the weak position is The first opening position of the pressure relief area 2111 enables the pressure relief area 2111 to be opened in time when the interior of the battery cell 20 reaches the detonation pressure. The first slot section 2131 and the third slot section 2133 are linear slots extending along the second direction, so that the first slot section 2131 and the third slot section 2133 are arranged in parallel, and the cover body 211 is arranged along the second slot section 2132 and the fourth slot section. After the groove section 2134 is split, it can be opened more easily along the first groove section 2131 and the third groove section 2133, so as to increase the opening rate of the pressure relief area 2111 and realize rapid pressure relief.

Please refer to FIG. 10 , FIG. 11 and FIG. 12 . FIG. 10 is a schematic structural diagram of an end cap 21 provided in another embodiment of the present application. FIG. 11 is a schematic top view of end caps 21 provided by other embodiments of the present application. Fig. 12 is a cross-sectional view at position G-G in Fig. 11 . In some other embodiments, a part of the cover body 211 protrudes along the thickness direction to form a protrusion 2114 , and the pressure relief groove 213 is disposed on the protrusion 2114 .

The cover body 211 partially protrudes along the thickness direction of the cover body 211 to form a convex portion 2114, and the side of the cover body 211 opposite to the convex portion 2114 in the thickness direction will form a corresponding recessed space. On the one hand, it can accommodate the inside of the battery cell 20 The components are beneficial to increase the energy density of the battery cell 20 , on the other hand, it can increase the bending strength of the end cover 21 and improve the impact resistance of the end cover 21 .

The embodiment of the present application also provides a battery cell 20 , and the battery cell 20 includes an electrode assembly 22 , a casing 23 and the above-mentioned end cap 21 . The casing 23 has an accommodating space with one end open, and the accommodating space is used for accommodating the electrode assembly 22 . The end cap 21 is connected to the housing 23 and closes the opening.

The embodiment of the present application also provides a battery 100 . The battery 100 includes a box body 10 and the aforementioned battery cells 20 . The battery cells 20 are housed in the box body 10 .

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

The bottom wall of the box body 10 is the wall surface of the box body 10 opposite to the opening end of the box body 10 .

By arranging the end cap 21 on the 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 .

The embodiment of the present application also provides an electric device, the electric device includes the above-mentioned battery 100, and the battery 100 is used to provide electric energy.

According to some embodiments of the present application, please refer to FIG. 4 to FIG. 8 .

The embodiment of the present application provides an end cover 21 , and the end cover 21 includes a cover body 211 and a reinforcement part 212 . The cover body 211 has a pressure relief area 2111 , a reinforcement portion 212 protrudes from one side of the cover body 211 in the thickness direction, and the reinforcement portion 212 is disposed around the pressure relief area 2111 . The reinforcement part 212 includes two first connecting sections 2121 and two second connecting sections 2122. Along the circumferential direction of the pressure relief area 2111, one first connecting section 2121, one second connecting section 2122, and another first connecting section 2121 It is sequentially connected with another second connecting section 2122 to form a closed structure. The two first connecting sections 2121 are arranged oppositely along the first direction, and the two second connecting sections 2122 are arranged oppositely along the second direction. The first direction is perpendicular to the second direction. Wherein, the dimension D1 of the first connecting section 2121 in the first direction is greater than the dimension D2 of the second connecting section 2122 in the second direction. The dimension D1 of the first connection section 2121 in the first direction is 5%-35% of the dimension L1 of the first connection section 2121 in the second direction. The dimension D2 of the second connection section 2122 in the second direction is 5%-30% of the dimension L2 of the second connection section 2122 in the first direction.

The corresponding position of the cover body 211 and the reinforcement part 212 is provided with a groove 214. Along the thickness direction, the cover body 211 has an opposite inner surface 2113 and an outer surface 2112. The surface 2112 is concave toward the direction close to the inner surface 2113 . The inner sidewall of the reinforcing part 212 defines a first space 2124 , and the sidewall 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 two sides of the pressure relief area 2111 .

The outer side of the pressure relief area 2111 of the end cover 21 is provided with a reinforcing part 212 , which strengthens the strength of the pressure relief area 2111 and improves the impact resistance of the pressure relief area 2111 . In this way, when the end cover 21 is subjected to an external impact, the reinforcing part 212 can absorb the energy of the external impact, reduce the impact force transmitted to the pressure relief area 2111, and avoid the damage of the pressure relief area 2111 due to the external impact to a certain extent. Furthermore, ensure that the pressure relief area 2111 can realize the normal pressure relief function, that is, prevent the pressure relief area 2111 from opening when the internal pressure of the battery cell 20 does not reach the detonation pressure, so as to ensure the normal operation of the battery cell 20 . The two first connecting sections 2121 and the two second connecting sections 2122 are respectively located in four different directions, and the two first connecting sections 2121 and the two second connecting sections 2122 are connected to form a closed structure with strong strength. The impact resistance of the pressure relief area 2111 can be effectively improved. In addition, since the dimension D1 of the first connecting section 2121 in the first direction is larger than the dimension D2 of the second connecting section 2122 in the second direction, the dimension L2 of the second connecting section 2122 in the first direction can be smaller than that of the first connecting section 2122. The dimension L1 of the segment 2121 in the second direction is such that the reinforcing capacity of the first connecting segment 2121 is equivalent to that of the second connecting segment 2122 , reducing the space occupied by the reinforcing part 212 and reducing material waste.

When the dimension D1 of the first connecting section 2121 in the first direction is lower than 5% of the dimension L1 of the first connecting section 2121 in the second direction, the reinforcing effect of the first connecting section 2121 is insufficient, and the end cover 21 is subjected to external When impacting, it cannot effectively absorb the energy of external impact. When the dimension D1 of the first connecting section 2121 in the first direction is greater than 35% of the dimension L1 of the first connecting section 2121 in the second direction, the volume occupied by the first connecting section 2121 is large, and there is enough After the reinforcing effect, continuing to increase the dimension D1 of the first connecting section 2121 in the first direction also results in waste of materials. When the dimension D2 of the second connecting section 2122 in the second direction is lower 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 cover 21 is subjected to external When impacting, it cannot effectively absorb the energy of external impact. 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 there is enough After the reinforcing effect, continuing to increase the dimension D2 of the second connecting section 2122 in the second direction also results in waste of materials.

By opening the groove 214 on the outer surface 2112 of the cover body 211 , the groove 214 plays a role of thinning, so that the thickness of the pressure relief area 2111 is reduced. When the internal pressure of the battery cell 20 reaches the detonation pressure, the pressure relief area 2111 is more likely to be opened by the internal pressure, thereby achieving pressure relief. The arrangement of the groove 214 makes the pressure relief area 2111 more likely to be washed away by the internal pressure, and also easier to be washed away by the external impact. Therefore, when the end cover 21 is subjected to an external impact, the reinforcement part 212 can absorb the energy of the impact and reduce the magnitude of the impact force transmitted to the pressure relief area 2111, so as to reduce the impact of the external impact on the pressure relief area 2111, and to a certain extent avoid The pressure relief area 2111 is damaged due to external impact, ensuring that the normal pressure relief function can be realized. By making the pressure relief area 2111 located 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 thinning effect of the groove 214 is better.

The above descriptions are only preferred embodiments of the present application, and are not intended to limit the present application. For those skilled in the art, various modifications and changes may be made to the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application shall be included within the protection scope of this application.

Claims (17)

1. An end cap, characterized in that, comprising: The cover body has a pressure relief area; The reinforcing part is protrudingly provided on one side of the cover body in the thickness direction, and the reinforcing part is arranged around the pressure relief area. 2. The end cap according to claim 1, wherein the reinforcing part comprises two first connecting sections and two second connecting sections, and along the circumferential direction of the pressure relief area, one of the first connecting sections segment, one of the second connecting segment, the other of the first connecting segment and the other of the second connecting segment are sequentially connected end to end to form a closed structure; The two first connecting sections are arranged opposite to each other along a first direction, the two second connecting sections 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 connection section in the first direction is larger than the size of the second connection section in the second direction. 3. The end cap according to claim 2, wherein the size of the first connection section in the first direction is 5% to 5% of the size of the first connection section in the second direction. 35%. 4. The end cap according to claim 2 or 3, wherein the size of the second connecting section in the second direction is 5 times the size of the second connecting section in the first direction %~30%. 5. The end cap according to claim 2 or 3, wherein the reinforcing portion comprises at least one arc segment, and one of the first connecting segment and one of the second connecting segment passes through one of the arc segments connect. 6. The end cap according to claim 1, wherein a groove is provided at a position corresponding to the reinforcing part of the cover body, and along the thickness direction, the cover body has an inner surface and an outer surface opposite to each other. The reinforcing part is protruded on the inner surface, and the groove is recessed from the outer surface in a direction close to the inner surface. 7. The end cap according to claim 6, wherein the inner side wall of the reinforcing part defines a first space, the side wall and the bottom wall of the groove define a second space, and along the thickness direction, The first space and the second space are located on two sides of the pressure relief area. 8. The end cap according to claim 1, wherein the pressure relief area 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 an end-to-end closed track. 10. The end cap according to claim 8 or 9, characterized in that, along the thickness direction, the reinforcement part and the pressure relief groove are respectively located on two sides of the pressure relief area. 11. The end cap according to claim 8 or 9, wherein the pressure relief groove comprises a first groove section, a second groove section, a third groove section and a fourth groove section which are sequentially connected; Along the first direction, the first groove segment and the third groove segment are arranged oppositely, and the maximum distance between the first groove segment and the third groove segment is a first distance; Along the second direction, the second groove segment and the fourth groove segment are arranged oppositely, and the minimum distance between the second groove segment and the fourth groove segment is the 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 section and the third slot section are linear slots; and/or The second groove segment and the fourth groove segment are arc grooves. 13. The end cap according to claim 1, characterized in that, a part of the cap body protrudes along the thickness direction to form a convex portion, and the reinforcing portion protrudes from one side of the convex portion in the thickness direction. side. 14. A battery cell, comprising: electrode assembly; A casing having an accommodating space with one end open, the accommodating space is used to accommodate the electrode assembly; The end cover according to any one of claims 1-13, wherein the end cover is connected to the housing and closes the opening. 15. A battery, characterized in that it comprises: box; The battery cell according to claim 14, the battery cell is accommodated in the case. 16 . The battery according to claim 15 , wherein the end cap is disposed on a side of the battery cell close to the bottom wall of the box. 17 . 17. An electrical device, characterized by comprising the battery according to any one of claims 15-16, the battery being used to provide electrical energy.

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