CN216698639U

CN216698639U - End cover assembly, single battery, electric equipment and single battery manufacturing equipment

Info

Publication number: CN216698639U
Application number: CN202123359267.4U
Authority: CN
Inventors: 靳超; 任苗苗; 谭显明; 谢勇锋; 李全坤; 王鹏
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2021-12-28
Filing date: 2021-12-28
Publication date: 2022-06-07
Anticipated expiration: 2031-12-28

Abstract

The application provides an end cover assembly, single battery, consumer and single battery's manufacture equipment, relates to battery technical field. The end cover assembly comprises an end cover and a pressure relief mechanism; the pressure relief mechanism is arranged on the end cover and is used for actuating when the internal pressure or temperature of the single battery reaches a threshold value so as to relieve the internal pressure of the single battery; the end cover is provided with a thinning area, and the thinning area is positioned between the edge of the end cover and the pressure relief mechanism and arranged around the pressure relief mechanism. The edge of the end cover can be separated from the pressure relief mechanism by the thinning region, the connecting region of the end cover and the single shell of the battery is separated from the pressure relief mechanism by the thinning region, the stress generated by connecting the end cover and the single shell of the battery is released in the thinning region, so that the problem of influence on the strain intensity of the pressure relief mechanism caused by the stress generated by connecting the end cover and the single shell of the battery is improved, the influence on the pressure relief intensity of the pressure relief mechanism caused by the stress generated by connection is reduced, and the influence on the pressure relief capability of the pressure relief mechanism is further reduced.

Description

End cover assembly, single battery, electric equipment and single battery manufacturing equipment

Technical Field

The application relates to the technical field of batteries, in particular to an end cover assembly, a single battery, a battery, electric equipment and single battery manufacturing equipment.

Background

Lithium ion storage batteries have outstanding advantages of high energy density, good cycle performance and the like, become mainstream products of secondary batteries, and are widely applied to the fields of portable electrical appliances, power automobiles, mobile phones, spacecrafts and the like.

The battery generally includes a case, an end cap assembly covering the case to provide a sealed space for the electrode assembly and an electrolyte, and an electrode assembly having an electrode terminal through which electric energy is drawn out of the case.

In order to ensure the safety performance of the battery, a pressure relief mechanism is generally arranged in the end cover assembly, and when the internal pressure or temperature of the battery reaches a threshold value, the pressure inside the battery can be relieved through the pressure relief mechanism. Whether the pressure relief mechanism can directly and effectively relieve the pressure directly influences the safety performance of the battery. Therefore, how to ensure that the pressure relief mechanism can relieve pressure in time is a problem to be solved urgently in the battery technology.

SUMMERY OF THE UTILITY MODEL

The embodiment of the application provides an end cover assembly, a single battery, a battery, electric equipment and single battery manufacturing equipment to improve the problem that the existing single battery pressure relief mechanism cannot timely relieve pressure.

In a first aspect, an end cap assembly for a battery cell includes an end cap and a pressure relief mechanism; the pressure relief mechanism is arranged on the end cover and is used for actuating when the internal pressure or temperature of the battery monomer reaches a threshold value so as to relieve the internal pressure of the battery monomer; the end cover is provided with a thinning area, and the thinning area is located between the edge of the end cover and the pressure relief mechanism and surrounds the pressure relief mechanism.

Among the above-mentioned technical scheme, the end cover is provided with between the edge of end cover and the pressure relief mechanism and encircles pressure relief mechanism and thins the district, it can separate the edge of end cover and pressure relief mechanism to thin the district promptly, it separates the joining region of end cover and the free shell of battery with the pressure relief mechanism to cut thin the district promptly, the stress that the end cover is connected the production with the free shell of battery is released in the district that thins, in order to improve because of the stress produces the problem of influence to pressure relief mechanism's strain intensity of end cover and the free shell of battery connection, thereby reduce the influence of the stress that produces to pressure relief mechanism's pressure release intensity, and then reduce the influence to pressure relief mechanism's pressure release capacity, in order to make pressure relief mechanism can in time release the free inside pressure of battery, reduce the risk of taking place the safety problem.

In some embodiments of the first aspect of the present application, the thinned region is a closed loop structure formed around the pressure relief mechanism.

Among the above-mentioned technical scheme, the district of thinning is the closed loop construction who forms around pressure relief mechanism, the district of thinning can separate the optional position of the edge of end cover with pressure relief mechanism, thereby make the stress that end cover and the free shell of battery are connected and are produced released in the district of thinning, can reduce the stress of the arbitrary position of being connected with the free shell of battery of the extending direction of end cover edge of end cover to pressure relief mechanism's influence, and make the strain intensity of each part of pressure relief mechanism tend to unanimous, thereby guarantee pressure relief mechanism's bursting pressure's uniformity, thereby reduce the influence to pressure relief mechanism's pressure relieving capacity, so that pressure relief mechanism can in time release the free inside pressure of battery, reduce the risk of taking place safety problem.

In some embodiments of the first aspect of the present application, the end cap includes a rim portion for welding with a housing of the battery cell, the thinned region is located between the rim portion and the pressure relief mechanism, and a maximum thickness of the rim portion is greater than a thickness of the thinned region.

In the technical scheme, the edge part is used for being welded with the single battery shell, and welding stress can be generated by welding to influence the strain strength of the pressure relief mechanism. The area of thinning is located between edge portion and the pressure relief mechanism, and the area of thinning separates edge portion and pressure relief mechanism, and the welding stress that edge portion and single welding of battery produced is released in the area of thinning, can reduce the influence of welding stress to pressure relief mechanism to reduce the influence to pressure relief mechanism's pressure release capacity, so that pressure relief mechanism can in time discharge the single inside pressure of battery, reduce the risk that takes place the safety problem.

In some embodiments of the first aspect of the present application, the distance H between the outer profile of the end cap and the outer edge of the thinned region satisfies: h is more than 4 mm.

In the technical scheme, the distance H between the outer contour of the end cover and the outer edge of the thinning area is larger than 4mm, so that enough space is reserved for connecting the end cover and the single battery shell, and the end cover is conveniently connected with the single battery shell.

In some embodiments of the first aspect of the present application, one surface of the end cap is provided with a groove in a thickness direction of the end cap, the end cap forming the thinned region in a region of the groove.

Among the above-mentioned technical scheme, set up the recess on a surface of the thickness direction of end cover, the regional thinning district that forms of this recess is convenient for thin district machine-shaping, reduces the processing degree of difficulty.

In some embodiments of the first aspect of the present application, in a thickness direction of the end cap, the end cap has first and second opposing surfaces, at least one of the first and second surfaces is provided with a groove, the end cap forms the thinned region in an area of the groove, a distance L between the first and second surfaces and a thickness L1 of the thinned region satisfy: L1/L is more than or equal to 0.50 and less than or equal to 0.75.

In the above technical solution, a ratio L1/L of a thickness L1 of the skived zone to a distance L between the first surface and the second surface satisfies: L1/L is more than or equal to 0.50 and less than or equal to 0.75, and the structural strength of the end cover can be ensured when the stress generated when the end cover is connected with the single battery shell is released, so that the structural strength of the single battery using the end cover assembly and the structural strength of the thinned area are ensured to be less than the pressure relief strength of the pressure relief mechanism, and the pressure relief mechanism is prevented from losing efficacy.

In some embodiments of the first aspect of the present application, an area S of a projection of the end cap in a thickness direction of the end cap and an area S1 of a projection of the thinned region in the thickness direction of the end cap satisfy: S1/S is more than or equal to 0.1 and less than or equal to 0.6.

In the technical scheme, the area S of the projection of the end cover along the thickness direction of the end cover and the area S1 of the projection of the thinning region along the thickness direction of the end cover meet the condition that S1/S is more than or equal to 0.1 and less than or equal to 0.6, the area of the thinning region can be controlled within a reasonable range, and the problem that the integral structural strength of the end cover cannot meet the use requirement due to the fact that the area of the thinning region is too large is avoided.

In some embodiments of the first aspect of the present application, the end cap assembly further includes a positive electrode terminal and a negative electrode terminal for outputting electrical energy of the battery cell, the positive electrode terminal and the negative electrode terminal are disposed at an interval in the first direction at the end cap, and the thinned region is located between the positive electrode terminal and the negative electrode terminal.

Among the above-mentioned technical scheme, the district of thinning is located between positive electrode terminal and the negative electrode terminal, the district of thinning can separate positive electrode terminal and pressure relief mechanism and separate negative electrode terminal and pressure relief mechanism, the stress that positive electrode terminal and end cover are connected and negative electrode terminal and end cover are connected and are produced is released in the district of thinning, it influences pressure relief mechanism's pressure release intensity to reduce the connection stress of electrode terminal and end cover, problem because of the connection stress of electrode terminal and end cover to pressure relief mechanism's strain intensity's influence is improved, thereby reduce the influence to pressure relief mechanism's pressure release capacity, so that pressure relief mechanism can in time release the inside pressure of battery monomer, reduce the risk that takes place the safety problem.

In some embodiments of the first aspect of the present application, the end cap is provided with a liquid injection hole, and the liquid injection hole is disposed in the thinning region.

Among the above-mentioned technical scheme, annotate the liquid hole and set up in cutting thin district, make things convenient for notes liquid hole manufacturing shaping.

In some embodiments of the first aspect of the present application, the end cap further includes an installation portion, the thinning region is formed around the installation portion, a concave portion is formed on a surface of the installation portion facing the inside of the battery cell, and the pressure relief mechanism is installed in the concave portion.

Among the above-mentioned technical scheme, the installation department is equipped with the depressed part of installation pressure relief mechanism towards the inside surface of battery monomer for pressure relief mechanism part at least can hold in the depressed part, reduces pressure relief mechanism and occupies the free inner space of battery.

In some embodiments of the first aspect of the present application, along a thickness direction of the end cap, a surface of the end cap close to the inside of the battery cell is provided with a groove, the end cap forms the thinning region in a region of the groove, the groove is surrounded at a periphery of the recess, a bottom wall of the groove is connected to an open end of a side wall of the recess, so that the groove is communicated with the recess.

Among the above-mentioned technical scheme, the diapire of recess links to each other with the open end of the lateral wall of depressed part, so that recess and depressed part intercommunication, the recess encircles the depressed part setting, thereby make to cut thin district and encircle pressure relief mechanism setting, it can separate the edge of end cover and pressure relief mechanism to cut thin the district, the stress that the end cover is connected the production with the free shell of battery is being cut thin the district and is released, in order to improve because of the stress produces the problem of influence to pressure relief mechanism's strain intensity of end cover and the free shell of battery, thereby reduce the influence of connecting the stress that produces to pressure relief mechanism's pressure relief intensity, and then reduce the influence to pressure relief mechanism's pressure release capacity, so that pressure relief mechanism can in time release the free inside pressure of battery, reduce the risk of taking place safety problem.

In some embodiments of the first aspect of the present application, the mounting portion protrudes from a surface of the thinned region facing away from the inside of the battery cell.

Among the above-mentioned technical scheme, the installation department protrusion is on the surface of the inside that the district deviates from the battery monomer in thinning, is convenient for the installation of the single other structure of battery (for example the protection piece).

In a second aspect, embodiments of the present application provide a battery cell, including a case, an electrode assembly, and the end cap assembly provided in the first aspect; the housing has an opening; the electrode assembly is housed within the case; the end cap assembly is used for covering the opening.

Among the above-mentioned technical scheme, the free end cover of battery is located between the edge of end cover and the pressure relief mechanism and encircles the setting of pressure relief mechanism, it can separate the edge of end cover and pressure relief mechanism to cut thin the district promptly, it separates the joining region of end cover and shell with the pressure relief mechanism to cut thin the district promptly, the stress that the end cover is connected the production with the shell is being cut thin the district and is released, reduce the pressure relief intensity to pressure relief mechanism and produce the influence, in order to improve because of the influence of end cover and shell connection to pressure relief mechanism's strain intensity, thereby reduce the influence to pressure relief mechanism's pressure release capacity, in order to make pressure relief mechanism can in time release the free inside pressure of battery, reduce the risk that takes place the safety problem.

In some embodiments of the second aspect of the present application, the end cap has a rim portion that is welded to the housing.

Among the above-mentioned technical scheme, the end cover passes through edge portion and shell welding with the shell to realize that the end cover is connected with the shell, connected mode is simple and convenient, firm reliable.

In some embodiments of the first aspect of the present application, the rim portion is welded to the housing to form a weld zone at the rim portion, and a distance M between an inner edge of the weld zone and an outer edge of the thinned region satisfies M > 3 mm.

Among the above-mentioned technical scheme, the distance M between the inward flange in seal of welding district and the outward flange in the district of thinning is greater than 3mm, so that the welding position with thin and have sufficient space between the district, welding stress can be released in the district of thinning as far as possible completely, the reduction produces the influence to pressure relief mechanism's pressure release intensity, so as to improve because of the influence of end cover and the free shell of battery connection to pressure relief mechanism's strain intensity, thereby reduce the influence to pressure relief mechanism's pressure release capacity, so that pressure relief mechanism can in time release the free inside pressure of battery, reduce the risk that takes place the safety problem.

In a third aspect, an embodiment of the present application provides a battery, including the battery cell provided in the embodiment of the second aspect.

In a fourth aspect, an embodiment of the present application provides an electric device, including the battery cell provided in the embodiment of the second aspect.

In a fifth aspect, an embodiment of the present application provides a manufacturing apparatus of a battery cell, including a providing device and an assembling device; the providing means is configured to provide an end cap assembly, a housing, and an electrode assembly; the end cover assembly comprises an end cover and a pressure relief mechanism, the pressure relief mechanism is arranged on the end cover, and the pressure relief mechanism is used for actuating when the internal pressure or temperature of the single battery reaches a threshold value so as to relieve the internal pressure of the single battery; the end cover is provided with a thinning area, and the thinning area is positioned between the edge of the end cover and the pressure relief mechanism and surrounds the pressure relief mechanism; the housing has an opening; the assembly device is configured to receive the electrode assembly within the housing and to cover the end cap assembly over the opening.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained from the drawings without inventive effort.

FIG. 1 is a schematic illustration of a vehicle according to some embodiments of the present application;

fig. 2 is a schematic structural diagram of a battery provided in some embodiments of the present application;

fig. 3 is an exploded view of a battery cell provided in some embodiments of the present application;

FIG. 4 is a schematic structural view of an end cap assembly provided in accordance with some embodiments of the present application;

FIG. 5 is a schematic structural view of an end cap assembly provided in accordance with further embodiments of the present application;

FIG. 6 is an isometric view of an endcap assembly provided in accordance with still further embodiments of the present application;

FIG. 7 is a top view of the end cap assembly of FIG. 6;

FIG. 8 is a partial cross-sectional view of an end cap provided in accordance with some embodiments of the present application;

FIG. 9 is a partial cross-sectional view of an end cap provided in accordance with further embodiments of the present application;

FIG. 10 is a partial cross-sectional view of an end cap provided in accordance with still other embodiments of the present application;

FIG. 11 is a partial cross-sectional view of an end cap provided in accordance with other embodiments of the present application;

FIG. 12 is a cross-sectional view of an end cap provided by some embodiments of the present application;

FIG. 13 is an enlarged view taken at I in FIG. 12;

FIG. 14 is a schematic view of the pressure relief mechanism mounted to the recess;

fig. 15 is a schematic structural diagram of a manufacturing apparatus of a battery cell according to some embodiments of the present application.

Icon: 1000-a vehicle; 100-a battery; 10-a box body; 11-a closed space; 12-a first part; 13-a second part; 20-a battery cell; 21-a housing; 211-an opening; 22-an electrode assembly; 221-positive pole tab; 222-a negative electrode tab; 23-an end cap assembly; 231-end caps; 2311-positive electrode terminal mounting holes; 2312-negative electrode terminal mounting holes; 2313-thinning zone; 2313 a-thinning the outer edge of the zone; 2313 b-thinning the inner edge of the region; 2314-edge portion; 2314 a-outer contour of end cap; 2315-grooving; 2316-a first surface; 2317-a second surface; 2318-liquid injection hole; 2319-an installation part; 2319 a-pressure relief vent; 2319 b-a recess; 232-a pressure relief mechanism; 24-an electrode terminal; 24 a-positive electrode terminal; 24 b-negative electrode terminal; 25-a current collecting member; 25 a-a positive current collecting member; 25 b-a negative current collecting member; 200-a controller; 300-a motor; 2000-manufacturing equipment of battery cells; 2100-providing means; 2200-an assembly device; x-thickness direction of end caps.

Detailed Description

In order to make the objects, 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 and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. The components of the embodiments of the present application, as generally described and illustrated in the figures herein, could be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present application, presented in the accompanying drawings, is not intended to limit the scope of the claimed application, but is merely representative of selected embodiments of the application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the embodiments of the present application, it should be noted that the indication of orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship which is usually placed when the product of the application is used, or the orientation or positional relationship which is conventionally understood by those skilled in the art, is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and operate, and thus, should not be construed as limiting the present application. Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.

At present, the application of the power battery is more and more extensive from the development of market situation. The power battery is not only applied to energy storage power supply systems such as hydraulic power, firepower, wind power and solar power stations, but also widely applied to electric vehicles such as electric bicycles, electric motorcycles, electric automobiles and the like, and a plurality of fields such as military equipment and aerospace. With the continuous expansion of the application field of the power battery, the market demand is also continuously expanding.

The battery cell includes a housing having an opening, an end cap assembly received within the housing, and an electrode assembly including an end cap and a pressure relief mechanism. The end cover is welded with the shell to seal the opening of the shell, and the pressure relief mechanism is arranged on the end cover and is used for actuating to relieve the internal pressure when the internal pressure or the temperature of the battery monomer reaches a preset threshold value.

The inventor finds that the welding stress generated by welding the end cover and the shell affects the strain intensity of the pressure relief mechanism, and the minimum pressure relief intensity of the pressure relief mechanism may be greater than the preset pressure relief intensity, so that the pressure inside the battery cell reaches the threshold value but does not reach the pressure relief intensity of the pressure relief mechanism, and the pressure inside the battery cell cannot be relieved, and the safety problem is caused in a short time.

Based on this, the embodiment of the application provides an end cover assembly, the end cover assembly comprises an end cover and a pressure relief mechanism, the pressure relief mechanism is arranged on the end cover, the end cover is provided with a thinning area between the edge of the end cover and the pressure relief mechanism and around the pressure relief mechanism, the thinning area can separate the edge of the end cover from the pressure relief mechanism, namely, the thinning area separates the connecting area of the end cover and the shell of the battery cell from the pressure relief mechanism, the stress generated by the connection of the end cover and the shell of the battery cell is released in the thinning area, so as to solve the problem that the stress generated by the connection between the end cover and the single battery shell affects the strain intensity of the pressure relief mechanism, thereby reducing the influence of the stress generated by the connection on the pressure relief intensity of the pressure relief mechanism, and then reduce the influence to pressure relief mechanism's pressure release ability to make pressure release mechanism can in time release the inside pressure of battery monomer, reduce the risk that takes place the safety problem.

The end cover assembly disclosed by the embodiment of the application can be used in a battery cell and a battery and can also be used in electric equipment such as vehicles, ships or aircrafts. The power supply system of the electric equipment can be formed by the single battery, the battery and the like with the end cover assembly disclosed by the application, so that the problem that the strain strength of the pressure relief mechanism is affected by the connection stress of the end cover and the single battery shell is favorably solved.

The end cap assembly described in the embodiments of the present application is suitable for batteries and electric devices using batteries.

The electric equipment can be vehicles, mobile phones, portable equipment, notebook computers, ships, spacecrafts, electric toys, electric tools and the like. The vehicle can be a fuel oil vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle or a range-extended vehicle and the like; spacecraft include aircraft, rockets, space shuttles, and spacecraft, among others; electric toys include stationary or mobile electric toys, such as game machines, electric car toys, electric ship toys, electric airplane toys, and the like; the electric power tools include metal cutting electric power tools, grinding electric power tools, assembly electric power tools, and electric power tools for railways, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, electric impact drills, concrete vibrators, and electric planers. The embodiment of the present application does not specifically limit the above-mentioned electric devices.

For convenience of explanation, the following embodiments will be described by taking an electric device as an example of a vehicle.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a vehicle 1000 according to some embodiments of the present disclosure. The battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided at the bottom or the head or the tail of the vehicle 1000. The battery 100 may be used for power supply of the vehicle 1000, for example, the battery 100 may serve as an operation power source of the vehicle 1000.

The vehicle 1000 may further include a controller 200 and a motor 300, the controller 200 being configured to control the battery 100 to supply power to the motor 300, for example, for starting, navigation, and operational power requirements while the vehicle 1000 is traveling.

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

Referring to fig. 2, fig. 2 is a schematic structural diagram of a battery 100 according to some embodiments of the present disclosure. The battery 100 includes a case 10 and a battery cell 20, and the battery cell 20 is housed in the case 10.

The case 10 is used to provide a sealed space 11 for the battery cell 20. In some embodiments, the case 10 may include a first portion 12 and a second portion 13, and the first portion 12 and the second portion 13 are mutually covered to define a closed space 11 for accommodating the battery cell 20. Of course, the joint between the first part 12 and the second part 13 can be sealed by a sealing member (not shown), which can be a sealing ring, a sealant, etc.

The first portion 12 and the second portion 13 may be in various shapes, such as a rectangular parallelepiped, a cylinder, or the like. The first portion 12 may be a hollow structure having one side opened to form an accommodating space for accommodating the battery cell 20, the second portion 13 may be a hollow structure having one side opened to form an accommodating space for accommodating the battery cell 20, and the open side of the second portion 13 is closed to the open side of the first portion 12 to form the case 10 having the closed space 11. Of course, the first portion 12 may have a hollow structure with one open side to accommodate the battery cell 20, the second portion 13 may have a plate-like structure, and the second portion 13 may be covered with the open side of the first portion 12 to form the case 10 having the closed space 11.

In the battery 100, one or more battery cells 20 may be provided. If there are a plurality of battery cells 20, the plurality of battery cells 20 may be connected in series, in parallel, or in series-parallel, where in series-parallel refers to that the plurality of battery cells 20 are connected in series or in parallel. The plurality of battery cells 20 can be directly connected in series or in parallel or in series-parallel, and the whole formed by the plurality of battery cells 20 is accommodated in the box body 10; of course, a plurality of battery cells 20 may be connected in series, in parallel, or in series-parallel to form a battery module, and a plurality of battery modules may be connected in series, in parallel, or in series-parallel to form a whole and be accommodated in the box 10. The battery cell 20 may be cylindrical, flat, rectangular parallelepiped, or other shape. Fig. 2 exemplarily shows a case where the battery cell 20 has a rectangular parallelepiped shape.

In some embodiments, the battery 100 may further include a bus member (not shown), and the plurality of battery cells 20 may be electrically connected to each other through the bus member, so as to connect the plurality of battery cells 20 in series or in parallel or in series-parallel.

Referring to fig. 3, fig. 3 is an exploded view of a battery cell 20 according to some embodiments of the present disclosure. Battery cell 20 may include a housing 21, an electrode assembly 22, and an end cap assembly 23. The case 21 has an opening 211, the electrode assembly 22 is accommodated in the case 21, and the cap assembly 23 is used to cover the opening 211.

The housing 21 may be in various shapes, such as a cylinder, a rectangular parallelepiped, or the like. The shape of the case 21 may be determined according to the specific shape of the electrode assembly 22. For example, if electrode assembly 22 is of cylindrical configuration, housing 21 may alternatively be of cylindrical configuration; if the electrode assembly 22 has a rectangular parallelepiped structure, the case 21 may have a rectangular parallelepiped structure. Fig. 3 exemplarily shows a case 21 and an electrode assembly 22 as cylinders.

The material of the housing 21 may be various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc., and the embodiment of the present invention is not limited thereto.

The electrode assembly 22 may include a positive electrode tab (not shown), a negative electrode tab (not shown), and a separator (not shown). The electrode assembly 22 may have a winding type structure formed by winding a positive electrode tab, a separator, and a negative electrode tab, or a lamination type structure formed by stacking a positive electrode tab, a separator, and a negative electrode tab. The electrode assembly 22 further includes a positive electrode tab 221 (not shown) and a negative electrode tab 222 (not shown), and may be a positive electrode collector of the positive electrode sheet, to which the positive electrode active material layer is not applied, as the positive electrode tab 221, and may be a negative electrode collector of the negative electrode sheet, to which the negative electrode active material layer is not applied, as the negative electrode tab 222.

The cap assembly 23 is used to cover the opening 211 of the case 21 to form a closed receiving space (not shown) for receiving the electrode assembly 22. The receiving space is also used for receiving an electrolyte, such as an electrolytic solution. The end cap assembly 23 serves as a component for outputting electrical energy of the electrode assembly 22, and the electrode terminal 24 in the end cap assembly 23 is used for electrical connection with the electrode assembly 22, that is, the electrode terminal 24 is electrically connected with a tab of the electrode assembly 22, for example, the electrode terminal 24 and the tab are connected through a current collecting member 25, so as to electrically connect the electrode terminal 24 with the tab. As shown in fig. 3, the positive electrode tab 221 and the positive electrode terminal 24a are connected by the positive current collecting member 25a, and the negative electrode tab 222 and the negative electrode terminal 24b are connected by the negative current collecting member 25 b.

One or two openings 211 of the housing 21 may be provided. If the opening 211 of the case 21 is one, the end cap assembly 23 may be one, and two electrode terminals 24 may be disposed in the end cap assembly 23, the two electrode terminals 24 are respectively used for electrically connecting with the positive electrode tab 221 and the negative electrode tab 222 of the electrode assembly 22, and the two electrode terminals 24 in the end cap assembly 23 are respectively a positive electrode terminal 24a and a negative electrode terminal 24 b. If the number of the openings 211 of the housing 21 is two, for example, two openings 211 are disposed on two opposite sides of the housing 21, the number of the end cover assemblies 23 may also be two, and two end cover assemblies 23 respectively cover the two openings 211 of the housing 21. In this case, it may be that the electrode terminal 24 in one end cap assembly 23 is a positive electrode terminal 24a for electrical connection with the positive electrode tab 221 of the electrode assembly 22; the electrode terminal 24 in the other end cap assembly 23 is a negative electrode terminal 24b for electrical connection with the negative electrode tab of the electrode assembly 22.

In some embodiments, the end cap 231 is provided with a positive electrode terminal mounting hole 2311 (shown in fig. 4) and a negative electrode terminal mounting hole 2312 (shown in fig. 4), the positive electrode terminal mounting hole 2311 being used for mounting the positive electrode terminal 24a, and the negative electrode terminal mounting hole 2312 being used for the negative electrode terminal 24 b. The positive electrode terminal mounting hole 2311 and the negative electrode terminal mounting hole 2312 may be countersunk holes.

Referring to fig. 3 and 4 in combination, an end cap assembly 23 for a battery cell 20 is provided in an embodiment of the present application, where the end cap assembly 23 includes an end cap 231 and a pressure relief mechanism 232; the pressure relief mechanism 232 is disposed on the end cap 231, and the pressure relief mechanism 232 is configured to be actuated when the internal pressure or temperature of the battery cell 20 reaches a threshold value, so as to relieve the internal pressure of the battery cell 20; the end cap 231 is provided with a thinned area 2313, and the thinned area 2313 is located between the edge of the end cap 231 and the pressure relief mechanism 232 and surrounds the pressure relief mechanism 232.

The end cap 231 is adapted to be coupled to the housing 21 to close the opening 211 of the housing 21. The end cap 231 and the housing 21 may be connected by welding or other connection means. In embodiments where the end cap 231 is welded to the housing 21, it may be laser welded, through-welded, or the like.

The pressure relief mechanism 232 refers to an element or a component that is actuated to relieve the internal pressure or temperature of the battery cell 20 when the internal pressure or temperature reaches a predetermined threshold. The threshold design varies according to design requirements. The threshold may depend on the material of one or more of the positive electrode tab, the negative electrode tab, the electrolyte and the separator in the battery cell 20. The pressure relief mechanism 232 may take the form of, for example, an explosion-proof valve, an explosion-proof sheet, a gas valve, a pressure relief valve, or a safety valve, and may specifically adopt a pressure-sensitive or temperature-sensitive element or configuration, that is, when the internal pressure or temperature of the battery cell 20 reaches a predetermined threshold value, the pressure relief mechanism 232 performs an action or a weak structure provided in the pressure relief mechanism 232 is broken, thereby forming an opening 211 or a passage through which the internal pressure or temperature can be relieved.

As used herein, "activate" means that the pressure relief mechanism 232 is activated or activated to a certain state, so that the internal pressure and temperature of the battery cell 20 can be relieved. The actions generated by the pressure relief mechanism 232 may include, but are not limited to: at least a portion of the pressure relief mechanism 232 ruptures, fractures, is torn or opened, or the like. When the pressure relief mechanism 232 is activated, the high-temperature and high-pressure substances inside the battery cell 20 are discharged as an exhaust from the activated portion. In this way, the battery cell 20 can be vented and warmed under controlled pressure or temperature, thereby avoiding potentially more serious accidents.

Emissions from the battery cell 20 as referred to in this application include, but are not limited to: electrolyte, dissolved or split positive and negative pole pieces, fragments of a separation film, high-temperature and high-pressure gas generated by reaction, flame and the like.

The thinned area 2313 is disposed around the pressure relief mechanism 232 in the sense that the thinned area 2313 is located at the periphery of the pressure relief mechanism 232 and extends along the periphery of the pressure relief mechanism 232. The thinned area 2313 may be in the form of an open loop surrounding the pressure relief mechanism 232. In some embodiments, where the strain strength of a portion of the pressure relief mechanism 232 is more affected by the stress at the connection of the end cap 231 and the housing 21 and less affected by the stress at the connection of the end cap 231 and the housing 21, a thinned region 2313 may be provided between the edge of the end cap 231 and the area of the pressure relief mechanism 232 that is more affected by the stress at the connection of the end cap 231 and the housing 21. As shown in fig. 4 and 5, two flat portions of the explosion proof plate having an oval shape of the pressure relief mechanism 232 are more affected by the connection stress of the end cap 231 and the housing 21 with respect to the bent portion, and therefore, a thinned region 2313 is provided between the flat portion of the explosion proof plate and a portion of the end cap 231 where the edge corresponds to the flat portion. In fig. 4, the thinned region 2313 extends in a direction parallel to the flat portion of the rupture disk, and in fig. 5, a portion of the thinned region 2313 extends in a direction parallel to the flat portion of the rupture disk, and another portion extends in an extending direction of the bent portion of the rupture disk, and a closed loop structure is not formed.

Of course, the skived area 2313 may also be a closed loop structure.

The end cover 231 is provided with a thinning area 2313 between the edge of the end cover 231 and the pressure relief mechanism 232 and surrounding the pressure relief mechanism 232, the thinning area 2313 can separate the edge of the end cover 231 from the pressure relief mechanism 232, namely the thinning area 2313 separates the connecting area of the end cover 231 and the shell 21 of the battery cell 20 from the pressure relief mechanism 232, and the stress generated by the connection of the end cover 231 and the shell 21 of the battery cell 20 is released in the thinning area 2313, so that the problem that the strain strength of the pressure relief mechanism 232 is affected by the connection stress of the end cover 231 and the shell 21 of the battery cell 20 is solved, the effect of the stress generated by the connection on the pressure relief strength of the pressure relief mechanism 232 is reduced, the effect on the pressure relief capacity of the pressure relief mechanism 232 is reduced, the pressure relief mechanism 232 can timely relieve the pressure in the battery cell 20, and the risk of safety problems is reduced.

Referring to fig. 6 and 7, the thinned area 2313 is a closed loop structure formed around the pressure relief mechanism 232.

The thinned area 2313 is a closed loop formed around the pressure relief mechanism 232, and the pressure relief mechanism 232 is surrounded by the thinned area 2313. The thinned region 2313 has an inner edge and an outer edge, the inner edge 2313b of the thinned region refers to the side edge of the thinned region 2313 closest to the pressure relief mechanism 232, and the outer edge 2313a of the thinned region refers to the side edge of the thinned region 2313 furthest from the pressure relief mechanism 232. The area between the outer edge 2313a of the thinned region and the inner edge 2313b of the thinned region and the thinned region 2313.

The inner edge 2313b of the thinned region may be shaped to match the profile of the pressure relief mechanism 232, such as where the pressure relief mechanism 232 is an oval shaped burst disk and the inner edge 2313b of the thinned region is oval shaped. Of course, the inner edge 2313b of the thinned region may have other shapes, such as circular, rectangular, etc. The outer edge 2313a of the thinned region may be shaped to match the profile of the pressure relief mechanism 232, such as where the pressure relief mechanism 232 is an oval shaped burst disk and the outer edge 2313a of the thinned region is oval shaped. Of course, the outer edge 2313a of the thinned region may be other shapes, such as circular, rectangular, etc.

The thinning area 2313 is a closed-loop structure formed around the pressure relief mechanism 232, the thinning area 2313 can separate any position of the edge of the end cover 231 from the pressure relief mechanism 232, so that stress generated by connection of the end cover 231 and the shell 21 of the battery cell 20 is released in the thinning area 2313, the influence of the stress of the end cover 231 at any position connected with the shell 21 of the battery cell 20 along the extending direction of the edge of the end cover 231 on the pressure relief mechanism 232 can be reduced, the strain strength of each part of the pressure relief mechanism 232 tends to be consistent, the consistency of the burst pressure of the pressure relief mechanism 232 is ensured, the influence on the pressure relief capacity of the pressure relief mechanism 232 is reduced, the pressure relief mechanism 232 can timely relieve the pressure in the battery cell 20, and the risk of safety problems is reduced.

As shown in fig. 7, in some embodiments, the end cap 231 includes a rim 2314, the rim 2314 is configured to be welded to the housing 21 of the battery cell 20, a skived area 2313 is located between the rim and the pressure relief mechanism 232, and the maximum thickness of the rim 2314 is greater than the thickness of the skived area 2313.

The edge portion 2314 is a closed loop structure, and the positive electrode terminal 24a, the negative electrode terminal 24b, the pressure relief mechanism 232, and the thinned region 2313 are all surrounded by the edge portion 2314.

The edge portions 2314 may be of equal thickness, with the same thickness at any location of the edge portions 2314. In some cases, to facilitate welding of the end cap 231 to the housing 21 or to facilitate shape matching of the end cap 231 to the open end of the housing 21, the edge portion 2314 may be chamfered such that the edge portion 2314 is tapered, the thickness of the portion of the edge portion 2314 closer to the outer profile 2314a of the end cap is smaller, and the maximum thickness of the edge portion 2314 is the thickness of the edge portion 2314 furthest from the outer profile 2314a of the end cap.

It is noted that the dotted lines shown in fig. 4-7 are the inner contours of the edge portions 2314, which together with the outer contour 2314a of the end cap define the edge portions 2314.

The edge 2314 is intended to be welded to the case 21 of the battery cell 20, and welding may generate welding stress that affects the strain strength of the relief mechanism 232. The thinning area 2313 is located between the edge portion 2314 and the pressure relief mechanism 232, the edge portion 2314 is separated from the pressure relief mechanism 232 through the thinning area 2313, welding stress generated by welding of the edge portion 2314 and the battery monomer 20 is released in the thinning area 2313, the influence of the welding stress on the pressure relief mechanism 232 can be reduced, the influence on the pressure relief capacity of the pressure relief mechanism 232 is reduced, the pressure relief mechanism 232 can timely relieve the pressure inside the battery monomer 20, and the risk of safety problems is reduced.

In some embodiments, the distance H between the outer profile 2314a of the end cap and the outer edge 2313a of the thinned region satisfies: h is more than 4 mm.

The distance H between the outer profile 2314a of the end cap and the outer edge 2313a of the thinned region is the minimum distance between any position of the outer profile 2314a of the end cap and the outer edge 2313a of the thinned region. The distance between different positions of the outer profile 2314a of the end cap and the outer edge 2313a of the thinned region may be different or the same along the extension direction of the outer profile 2314a of the end cap. For example, in fig. 6 and 7, the end cap 231 has a rectangular shape, and the distance between the long side of the end cap 231 and the outer edge 2313a of the thinned region is smaller than the distance between the short side of the end cap 231 and the outer edge 2313a of the thinned region.

The distance H between the outer contour 2314a of the end cap and the outer edge 2313a of the thinned region is greater than 4mm, so that enough space is reserved for connecting the end cap 231 and the housing 21 of the battery cell 20, and the end cap 231 and the housing 21 of the battery cell 20 can be conveniently connected.

Referring to fig. 8, 9 and 10, in some embodiments, a groove 2315 is formed on one surface of the end cap 231 along the thickness direction X of the end cap, and the end cap 231 forms a thinning area 2313 in the area of the groove 2315.

Along the thickness direction X of the end cap, the end cap 231 has a first surface 2316 facing away from the interior of the battery cell 20 and a second surface 2317 facing the interior of the battery cell 20, wherein the first surface 2316 may be provided with a groove 2315, the second surface 2317 may be provided with a groove 2315, or both the first surface 2316 and the second surface 2317 may be provided with grooves 2315. In fig. 8 it is shown that the first surface 2316 is provided with grooves 2315 and the second surface 2317 is not provided with grooves 2315; fig. 9 shows that the first surface 2316 is not provided with the grooves 2315, and the second surface 2317 is provided with the grooves 2315, so that the residual space inside the battery cell 20 can be increased, and the energy density can be improved; fig. 10 shows that the first surface 2316 and the second surface 2317 are both provided with the grooves 2315, and the provision of the grooves 2315 on the second surface 2317 can increase the internal residual space of the battery cell 20, which is beneficial to increase the energy density.

A groove 2315 is formed in one surface of the end cover in the thickness direction X, and a thinning area 2313 is formed in the area of the groove 2315, so that the thinning area 2313 is convenient to machine and form, and the machining difficulty is reduced.

In some embodiments, in the thickness direction X of the end cap, the end cap 231 has a first surface 2316 and a second surface 2317 opposite to each other, at least one of the first surface 2316 and the second surface 2317 is provided with a groove 2315, the end cap 231 forms a thinned area 2313 in the area of the groove 2315, and the distance L between the first surface 2316 and the second surface 2317 and the thickness L1 of the thinned area 2313 satisfy: L1/L is more than or equal to 0.50 and less than or equal to 0.75.

In embodiments where first surface 2316 is provided with groove 2315 and second surface 2317 is not provided with groove 2315, the thickness L1 of thinned area 2313 is the distance between the bottom wall of groove 2315 and second surface 2317 in the thickness direction X of the end cap. In embodiments where first surface 2316 is not provided with grooves 2315 and second surface 2317 is provided with grooves 2315, the thickness L1 of thinned area 2313 is the distance between the bottom wall of groove 2315 and first surface 2316 in the thickness direction X of the end cap. In the embodiment where first surface 2316 and second surface 2317 are provided with grooves 2315, the thickness L1 of thinned area 2313 is the distance between the bottom wall of groove 2315 of first surface 2316 and the bottom wall of groove 2315 of second surface 2317 in the thickness direction X of the end cap.

If the thickness of the thinned area 2313 is too large, the stress generated by welding the end cap 231 and the housing 21 cannot be well released; if the thickness of the thinned area 2313 is too small, which may cause the strength of the thinned area 2313 to be less than the pressure relief strength of the pressure relief mechanism 232, when the pressure or temperature inside the battery cell 20 reaches a certain value, the thinned area 2313 of the end cap 231 is activated to relieve the pressure inside the battery cell 20. The ratio L1/L of the thickness L1 of the skived area 2313 to the distance L between the first and

second surfaces

2316, 2317 satisfies: L1/L is not less than 0.50 and not more than 0.75, and when the stress generated when the end cover 231 is connected with the shell 21 of the battery cell 20 is released, the structural strength of the end cover 231 can be ensured, so that the structural strength of the battery cell 20 using the end cover assembly 23 is ensured, and the situation that the pressure relief mechanism 232 fails due to the fact that the structural strength of the thinning area 2313 is smaller than the pressure relief strength of the pressure relief mechanism 232 is avoided.

In some embodiments, the area S of the projection of the end cap 231 in the thickness direction X of the end cap and the area S1 of the projection of the skived zone 2313 in the thickness direction X of the end cap satisfy: S1/S is more than or equal to 0.1 and less than or equal to 0.6.

If the area S1 of the projection of the thinned region 2313 in the thickness direction X of the end cap is too small in relation to the area S of the projection of the end cap 231 in the thickness direction X of the end cap, the thinned region 2313 cannot release the stress generated by welding the end cap 231 and the housing 21 well; if the area S1 of the projection of the thinned region 2313 in the thickness direction X of the end cap is too large relative to the area S of the projection of the end cap 231 in the thickness direction X of the end cap, the overall structural strength of the end cap 231 may be low. The area S of the projection of the end cover 231 in the thickness direction X of the end cover and the area S1 of the projection of the thinning area 2313 in the thickness direction X of the end cover meet the condition that S1/S is more than or equal to 0.1 and less than or equal to 0.6, the area of the thinning area 2313 can be controlled within a reasonable range, and the problem that the integral structural strength of the end cover 231 cannot meet the use requirement due to the fact that the area of the thinning area 2313 is too large is avoided.

In some embodiments, the end cap assembly 23 further includes a positive electrode terminal 24a and a negative electrode terminal 24b for outputting the electric energy of the battery cell 20, the positive electrode terminal 24a and the negative electrode terminal 24b are spaced apart from each other in the first direction at the end cap 231, and the thinning-out region 2313 is located between the positive electrode terminal 24a and the negative electrode terminal 24 b.

The thinned region 2313 is located between the positive electrode terminal 24a and the negative electrode terminal 24b, the thinned region 2313 can separate the positive electrode terminal 24a from the pressure relief mechanism 232, and the thinned region 2313 can separate the negative electrode terminal 24b from the pressure relief mechanism 232. In the embodiment where the thinning area 2313 is a closed loop structure, the thinning area 2313 surrounds the periphery of the pressure relief mechanism 232, and the positive electrode terminal 24a and the negative electrode terminal 24b are located at the periphery of the thinning area 2313, so that the thinning area 2313 separates the positive electrode terminal 24a from the pressure relief mechanism 232 and separates the negative electrode terminal 24b from the pressure relief mechanism 232.

The positive electrode terminal 24a is generally attached to the positive electrode terminal attachment hole 2311 of the end cap 231 by welding, and the negative electrode terminal 24b is generally attached to the negative electrode terminal attachment hole 2312 of the end cap 231 by welding. Of course, the positive electrode terminal 24a and the negative electrode terminal 24b may be attached to the end cap 231 in other manners. The thinning area 2313 is located between the positive electrode terminal 24a and the negative electrode terminal 24b, the thinning area 2313 can separate the positive electrode terminal 24 from the pressure relief mechanism 232 and separate the negative electrode terminal 24b from the pressure relief mechanism 232, stress generated by connection of the positive electrode terminal 24a and the end cover 231 and connection of the negative electrode terminal 24b and the end cover 231 is released at the thinning area 2313, the influence of the connection stress of the electrode terminal 24 and the end cover 231 on the pressure relief strength of the pressure relief mechanism 232 is reduced, the problem of influence of the connection stress of the electrode terminal 24 and the end cover 231 on the strain strength of the pressure relief mechanism 232 is solved, the influence on the pressure relief capacity of the pressure relief mechanism 232 is reduced, the pressure relief mechanism 232 can timely relieve the pressure in the battery cell 20, and the risk of safety problems is reduced.

Referring to FIG. 10, in some embodiments, the lid 231 has a liquid injection hole 2318, and the liquid injection hole 2318 is disposed in the thinning area 2313.

In other embodiments, referring to FIG. 11, the pour hole 2318 may be located in a location other than the skived section 2313 of the end cap 231. The liquid injection hole 2318 is formed in the thinning area 2313, so that the liquid injection hole 2318 is convenient to manufacture and mold.

Referring to fig. 12, 13 and 14, in some embodiments, the end cap 231 further includes a mounting portion 2319, the thinned region 2313 is formed around the mounting portion 2319, a recess 2319b is formed on a surface of the mounting portion 2319 facing the inside of the battery cell 20, and the pressure relief mechanism 232 is mounted in the recess 2319 b.

The mounting portion 2319 is provided with a pressure relief hole 2319a, and the pressure relief mechanism 232 is mounted to the mounting portion 2319 to cover the pressure relief hole 2319 a. When the pressure or temperature inside the battery cell 20 reaches a threshold value, the pressure relief mechanism 232 is actuated to discharge the substance inside the battery cell 20 through the pressure relief hole 2319 a. The pressure relief mechanism 232 may be disposed on a side of the mounting portion 2319 facing the inside of the battery cell 20, or may be disposed on a side of the mounting portion 2319 facing away from the outside of the battery cell 20. The recessed portions 2319b are recessed from the surface of the mounting portion 2319 facing the interior of the battery cell 20 in a direction away from the interior of the battery cell 20. The pressure relief mechanism 232 may be partially accommodated in the recess 2319b or entirely accommodated in the recess 2319b in the thickness direction X of the end cap. In other embodiments, the recess 2319b may also be provided at a side of the mounting portion 2319 facing away from the inside of the battery cell 20 and recessed from a surface of the mounting portion 2319 facing away from the inside of the battery cell 20 toward the inside near the battery cell 20.

The surface of the mounting portion 2319 facing the inside of the battery cell 20 is provided with a recessed portion 2319b for mounting the pressure relief mechanism 232, so that at least part of the pressure relief mechanism 232 can be accommodated in the recessed portion 2319b, the internal space of the battery cell 20 occupied by the pressure relief mechanism 232 is reduced, and the energy density of the battery cell 20 is favorably provided.

In some embodiments, the surface of the end cap 231 near the inside of the battery cell 20 in the thickness direction X of the end cap is provided with a groove 2315, the end cap 231 forms a thinned region 2313 in the region of the groove 2315, the groove 2315 surrounds the periphery of the recess 2319b, and the bottom wall of the groove 2315 is connected with the open end of the side wall of the recess 2319b, so that the groove 2315 is communicated with the recess 2319 b.

The bottom wall of the groove 2315 is closer to the inside of the battery cell 20 than the bottom wall of the recess 2319 b. The bottom wall of the groove 2315 is connected to the open end of the side wall of the recess 2319b, and the bottom wall of the groove 2315 is flush with the open end of the recess 2319 b. When the pressure relief mechanism 232 is mounted in the recess 2319b, the side of the pressure relief mechanism 232 facing the inside of the battery cell 20 is flush with the bottom wall of the groove 2315 or protrudes from the bottom wall of the groove 2315 in a direction close to the inside of the battery cell 20.

The bottom wall of the groove 2315 is connected with the open end of the side wall of the recess 2319b, so that the groove 2315 is communicated with the recess 2319b, the groove 2315 is arranged around the recess 2319b, so that the thinned region 2313 is arranged around the pressure relief mechanism 232, the edge of the end cover 231 can be separated from the pressure relief mechanism 232 through the thinned region 2313, stress generated by connection of the end cover 231 and the shell 21 of the battery cell 20 is released at the thinned region 2313, the problem that the stress generated by connection of the end cover 231 and the shell 21 of the battery cell 20 affects the strain strength of the pressure relief mechanism 232 is solved, the effect of the stress generated by connection on the pressure relief strength of the pressure relief mechanism 232 is reduced, the effect on the pressure relief capacity of the pressure relief mechanism 232 is reduced, the pressure relief mechanism 232 can timely relieve the pressure in the battery cell 20, and the risk of safety problems is reduced.

In some embodiments, the mounting portion 2319 protrudes from the surface of the thinned region 2313 facing away from the interior of the battery cell 20.

In the embodiment where the first surface 2316 is provided with the groove 2315 and the second surface 2317 is not provided with the groove 2315, the protrusion of the mounting portion 2319 from the surface of the thinned region 2313 away from the inner part of the battery cell 20 means that the mounting portion 2319 protrudes from the bottom wall of the groove 2315. In the embodiment where the first surface 2316 is not provided with the groove 2315 and the second surface 2317 is provided with the groove 2315, the protrusion of the mounting portion 2319 from the surface of the thinned region 2313 away from the inner part of the battery cell 20 means that the mounting portion 2319 protrudes from the first surface 2316. In the embodiment where the first surface 2316 and the second surface 2317 are provided with the grooves 2315, the surface of the mounting portion 2319 protruding from the inside of the thinned region 2313 away from the battery cell 20 means that the mounting portion 2319 protrudes from the bottom wall of the groove 2315 provided on the first surface 2316.

The mounting portion 2319 protrudes from the surface of the thinned region 2313 facing away from the interior of the battery cell 20, so that other structures (such as a protection sheet for protecting the pressure relief mechanism) of the battery cell 20 can be mounted conveniently.

The embodiment of the application provides an end cover assembly 23 of a square-shell battery 100, the end cover assembly 23 comprises an end cover 231, a pressure relief mechanism 232, a positive electrode terminal 24a and a negative electrode terminal 24b, and the end cover 231 is used for being welded with a shell 21 of the square-shell battery 100 and covers an opening 211 of the shell 21. The pressure relief mechanism 232 is elliptical, and the positive electrode terminal 24a, the negative electrode terminal 24b, and the pressure relief mechanism 232 are provided in the end cap 231. The end cap 231 is provided with a thinning area 2313, the thinning area 2313 is arranged between the edge of the end cap 231 and the pressure relief mechanism 232 and surrounds the pressure relief mechanism 232, and the pressure relief mechanism 232 is a closed loop structure formed around the pressure relief mechanism 232. The thinning area 2313 can separate any position of the edge of the end cover 231 from the pressure relief mechanism 232, so that stress generated by welding the end cover 231 and the shell 21 of the square-shell battery 100 is released in the thinning area 2313, the influence of the stress of any position, welded with the shell 21 of the battery cell 20, of the end cover 231 in the extending direction of the edge of the end cover 231 on the pressure relief mechanism 232 can be reduced, the strain strength of each part of the pressure relief mechanism 232 tends to be consistent, the consistency of the burst pressure of the pressure relief mechanism 232 is ensured, the influence on the pressure relief capacity of the pressure relief mechanism 232 is reduced, the pressure relief mechanism 232 can timely relieve the pressure inside the battery cell 20, and the risk of safety problems is reduced.

The thinning area 2313 is located between the positive electrode terminal 24a and the negative electrode terminal 24b, the thinning area 2313 can separate the positive electrode terminal 24 from the pressure relief mechanism 232 and separate the negative electrode terminal 24b from the pressure relief mechanism 232, stress generated by welding of the positive electrode terminal 24a and the end cover 231 and welding of the negative electrode terminal 24b and the end cover 231 is released at the thinning area 2313, the influence of the welding stress of the electrode terminal 24 and the end cover 231 on the pressure relief strength of the pressure relief mechanism 232 is reduced, the problem of influence of the welding stress of the electrode terminal 24 and the end cover 231 on the strain strength of the pressure relief mechanism 232 is solved, the influence on the pressure relief capacity of the pressure relief mechanism 232 is reduced, the pressure relief mechanism 232 can timely relieve the pressure in the battery cell 20, and the risk of safety problems is reduced.

The embodiment of the present application further provides a battery cell 20, where the battery cell 20 includes a housing 21, an electrode assembly 22, and the end cap assembly 23 provided in the foregoing embodiment; the housing 21 has an opening 211; the electrode assembly 22 is accommodated in the case 21; the cap assembly 23 is used to close the opening 211.

The end cover 231 of the battery cell 20 is located between the edge of the end cover 231 and the pressure relief mechanism 232 and is arranged around the pressure relief mechanism 232, the edge of the end cover 231 and the pressure relief mechanism 232 can be separated by the thinning area 2313, namely, the connecting area between the end cover 231 and the shell 21 and the pressure relief mechanism 232 are separated by the thinning area 2313, stress generated by connection of the end cover 231 and the shell 21 is released in the thinning area 2313, influence on the pressure relief strength of the pressure relief mechanism 232 is reduced, influence on the strain strength of the pressure relief mechanism 232 due to connection of the end cover 231 and the shell 21 is improved, influence on the pressure relief capacity of the pressure relief mechanism 232 is reduced, the pressure relief mechanism 232 can timely relieve the pressure in the battery cell 20, and the risk of safety problems is reduced.

In some embodiments, the end cap 231 has a rim 2314, and the rim 2314 is welded to the housing 21.

In other embodiments, the end cap 231 may be connected to the housing 21 by bolts, screws, etc.

The end cover 231 and the shell 21 are welded with the shell 21 through the edge portions 2314, so that the end cover 231 and the shell 21 are connected, and the connection mode is simple, convenient, firm and reliable.

In some embodiments, the rim portion is welded to the housing 21 to form a weld region at the rim portion 2314, and a distance M between an inner edge of the weld region and an outer edge 2313a of the thinned region satisfies M > 3 mm.

The outer edge of the footprint may or may not be flush with the outer profile of the end cap 231. The width of the edge portion 2314 may be the same as or different from the width of the solder printing area. In embodiments where the width of the edge portion 2314 is the same as the width of the footprint area, the outer edge of the footprint area may be flush with the outer profile of the end cap 231 (the outer edge of the edge portion 2314) and the inner edge of the footprint area may be flush with the inner edge of the edge portion 2314.

The distance M between the inner edge of the welding area and the outer edge 2313a of the thinning area is larger than 3mm, so that a sufficient space is reserved between the welding position and the thinning area 2313, welding stress can be released in the thinning area 2313 as completely as possible, the influence on the pressure relief strength of the pressure relief mechanism 232 is reduced, the influence on the strain strength of the pressure relief mechanism 232 due to connection of the end cover 231 and the shell 21 of the battery cell 20 is improved, the influence on the pressure relief capacity of the pressure relief mechanism 232 is reduced, the pressure relief mechanism 232 can timely relieve the pressure inside the battery cell 20, and the risk of safety problems is reduced.

The embodiment of the present application further provides a battery 100, which includes the battery cell 20 provided in the above embodiment.

The embodiment of the present application further provides an electric device, including the above battery cell 20.

Referring to fig. 15, an embodiment of the present application further provides a manufacturing apparatus 2000 for a battery cell, where the manufacturing apparatus 2000 for a battery cell includes a providing device 2100 and an assembling device 2200; the providing apparatus 2100 is configured to provide an end cap assembly 23, a housing 21, and an electrode assembly 22; the end cap assembly 23 includes an end cap 231 and a pressure relief mechanism 232, the pressure relief mechanism 232 is disposed on the end cap 231, and the pressure relief mechanism 232 is configured to be activated when the internal pressure or temperature of the battery cell 20 reaches a threshold value, so as to relieve the internal pressure of the battery cell 20; the end cover 231 is provided with a thinning area 2313, and the thinning area 2313 is positioned between the edge of the end cover 231 and the pressure relief mechanism 232 and surrounds the pressure relief mechanism 232; the housing 21 has an opening 211; assembly apparatus 2200 is configured to receive electrode assembly 22 within can 21 and to cover end cap assembly 23 over opening 211.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An end cap assembly for a battery cell, comprising:

an end cap; and

the pressure relief mechanism is arranged on the end cover and is used for actuating when the internal pressure or temperature of the battery monomer reaches a threshold value so as to relieve the internal pressure of the battery monomer;

the end cover is provided with a thinning area, and the thinning area is located between the edge of the end cover and the pressure relief mechanism and surrounds the pressure relief mechanism.

2. An end cap assembly according to claim 1, wherein the thinned region is a closed loop structure formed around the pressure relief mechanism.

3. An end cap assembly according to claim 1, wherein the end cap includes a rim portion for welding with a housing of the battery cell, the thinned region is located between the rim portion and the pressure relief mechanism, and a maximum thickness of the rim portion is greater than a thickness of the thinned region.

4. The end cap assembly of claim 1, wherein a distance H between an outer profile of the end cap and an outer edge of the thinned region satisfies: h is more than 4 mm.

5. An end cap assembly according to claim 1, wherein one surface of the end cap is provided with a groove in a thickness direction of the end cap, the end cap forming the thinned region in an area of the groove.

6. An end cap assembly according to claim 1, wherein the end cap has first and second opposing surfaces in a thickness direction of the end cap, at least one of the first and second surfaces being provided with a recess, the end cap forming the thinned region in the region of the recess, the distance L between the first and second surfaces and the thickness L1 of the thinned region being such that: L1/L is more than or equal to 0.50 and less than or equal to 0.75.

7. An end cap assembly according to any one of claims 1-6, wherein the projected area S of the end cap in the thickness direction of the end cap and the projected area S1 of the thinned region in the thickness direction of the end cap satisfy: S1/S is more than or equal to 0.1 and less than or equal to 0.6.

8. The end cap assembly of any of claims 1-6, further comprising a positive electrode terminal and a negative electrode terminal for outputting electrical energy from a battery cell, the positive electrode terminal and the negative electrode terminal spaced apart in the first direction at the end cap, the thinned region located between the positive electrode terminal and the negative electrode terminal.

9. An end cap assembly according to any one of claims 1 to 6 wherein a filler hole is provided in the end cap, the filler hole being provided in the thinned region.

10. An end cap assembly according to any one of claims 1 to 6, wherein the end cap is further provided with a mounting portion, the thinned region is formed around the mounting portion, a surface of the mounting portion facing the inside of the battery cell is provided with a recess, and the pressure relief mechanism is mounted in the recess.

11. An end cap assembly according to claim 10, wherein a surface of the end cap adjacent to the inside of the battery cell in a thickness direction of the end cap is provided with a groove, the end cap forms the thinned region in a region of the groove, the groove is provided around the periphery of the recess, and a bottom wall of the groove is connected to an open end of a side wall of the recess so that the groove communicates with the recess.

12. The end cap assembly of claim 10, wherein the mounting portion projects from a surface of the skived section facing away from an interior of the battery cell.

13. A battery cell, comprising:

a housing having an opening;

an electrode assembly housed within the case; and

the end cap assembly of any of claims 1-12, for capping the opening.

14. The battery cell of claim 13, wherein the end cap has a rim portion that is welded to the housing.

15. The battery cell as recited in claim 14, wherein the edge portion is welded to the case to form a solder mark region at the edge portion, and a distance M between an inner edge of the solder mark region and an outer edge of the thinned region satisfies M > 3 mm.

16. A battery comprising a cell according to any one of claims 13 to 15.

17. An electric device, characterized in that it comprises a battery cell according to any one of claims 13-15.

18. An apparatus for manufacturing a battery cell, comprising:

providing a device configured to provide an end cap assembly, a housing, and an electrode assembly;

the end cover assembly comprises an end cover and a pressure relief mechanism, the pressure relief mechanism is arranged on the end cover, and the pressure relief mechanism is used for actuating when the internal pressure or temperature of the single battery reaches a threshold value so as to relieve the internal pressure of the single battery; the end cover is provided with a thinning area, and the thinning area is positioned between the edge of the end cover and the pressure relief mechanism and surrounds the pressure relief mechanism;

the housing has an opening;

an assembly device configured to receive the electrode assembly within the housing and to cover the end cap assembly over the opening.