End cover assembly, battery monomer, battery and electric device

Abstract

An end cap assembly (500), a battery cell (20), a battery (100), and an electrical device. An end cap assembly (500) for a battery cell (20). The end cover assembly (500) comprises an end cover (21) and an electrode terminal (26), the end cover (21) is provided with an electrode leading-out hole (21a), the electrode terminal (26) comprises a connecting part (30) and a terminal main body (40), and the terminal main body (40) protrudes out of the connecting part (30) and is at least partially accommodated in the electrode leading-out hole (21a); the connecting part (30) is provided with a groove (30a), so that the weight of the battery monomer (20) is reduced, the internal space of the battery monomer (20) is saved, and the energy density of the battery monomer (20) is improved.

Description

End cap assembly, battery cell, battery and electrical device Technical Field

[0001] The present application relates to the technical field of batteries, and more particularly, to an end cap assembly, a battery cell, a battery, and an electric device. Background Art

[0002] Battery cells are widely used in electronic devices such as mobile phones, laptops, electric bicycles, electric cars, electric airplanes, electric boats, electric toy cars, electric toy boats, electric toy airplanes, and power tools. Battery cells can include nickel-cadmium battery cells, nickel-metal hydride battery cells, lithium-ion battery cells, and secondary alkaline zinc-manganese battery cells.

[0003] In the development of battery technology, how to improve the energy density of battery cells is a research direction in battery technology.

[0004] Summary of the Invention

[0005] The present application provides an end cap assembly, a battery cell, a battery, and an electrical device, which can improve the energy density of the battery cell.

[0006] In a first aspect, an embodiment of the present application provides an end cap assembly for a battery cell, the end cap assembly comprising an end cap and an electrode terminal, the end cap having an electrode lead-out hole; the electrode terminal comprising a connecting portion and a terminal body, the terminal body protruding from the connecting portion and at least partially accommodated in the electrode lead-out hole; the connecting portion is provided with a groove.

[0007] In the above scheme, the terminal body is accommodated in the electrode lead-out hole of the end cover, and the electric energy is led out through the terminal body; by providing a groove at the connection part, the tabs or other components of the electrode terminal of the battery cell can be accommodated in the groove, which not only reduces the weight of the battery cell, but also saves the internal space of the battery cell, thereby improving the energy density of the battery cell.

[0008] In some embodiments, the connection portion includes a first connection sub-portion and a second connection sub-portion, the second connection sub-portion is connected between the terminal body and the first connection sub-portion, and a thickness of the second connection sub-portion is smaller than that of the first connection sub-portion to form a groove.

[0009] In the above solution, the terminal body is connected to the thicker first connecting sub-portion, which can increase the connection strength between the terminal body and the connecting portion and improve the stability of the terminal body.

[0010] In some embodiments, a groove is provided on the surface of the electrode assembly where the connection portion faces the battery cell, so as to facilitate the accommodation of the electrode tab or other components of the electrode assembly in the groove, thereby facilitating process preparation and improving production efficiency.

[0011] In some embodiments, the surface of the first connecting sub-part facing the end cap is flush with the surface of the second connecting sub-part facing the end cap, which can improve the bearing capacity of the connecting part on the end cap and enhance the strength of the end cap assembly.

[0012] In some embodiments, in the thickness direction of the end cover, the thickness of the second connecting sub-part is H1, and the thickness of the first connecting sub-part is H2, then 1 / 5H2≤H1≤4 / 5H2, which can not only reduce the weight and internal capacity of the battery cell, but also ensure the strength of the second connecting sub-part.

[0013] In some embodiments, the first connecting sub-part and the second connecting sub-part are arranged along the first direction; in the second direction, at least one end of the second connecting sub-part extends beyond the first connecting sub-part, and the first direction, the second direction and the thickness direction of the end cover are perpendicular to each other.

[0014] In the above solution, at least one end of the second connecting sub-part extends beyond the first connecting sub-part, which can further reduce the weight of the connecting part, further save the internal space of the battery cell, and improve the energy density of the battery cell.

[0015] In some embodiments, there are two second connecting sub-parts, and the two second connecting sub-parts are respectively located on both sides of the first connecting sub-part along the first direction; the electrode terminal is provided with a weight-reducing groove, which is located on one side of the first connecting sub-part along the second direction and is surrounded by the first connecting sub-part and the two second connecting sub-parts.

[0016] In the above solution, the two second connectors are located on either side of the first connector along the first direction, allowing a single end cap assembly to connect to two electrode assemblies simultaneously, thereby increasing the energy density of the battery cell. The weight-reducing groove, enclosed by the first connector and the two second connectors, not only reduces the weight of the end cap assembly, conserves internal space within the battery cell, further increasing the energy density of the battery cell, but also provides more connection space for components connected to the second connector.

[0017] In some embodiments, the end cap assembly further includes a seal arranged around the terminal body, at least part of the seal is clamped between the end cap and the connecting portion, and in the thickness direction of the end cap, the projection of the weight reduction groove does not overlap with the projection of the seal.

[0018] In this solution, the sealant enhances the seal between the end cap and the electrode terminal, reducing the likelihood of battery cell leakage and improving battery cell safety. The projection of the weight-reducing groove and the sealant along the thickness of the end cap do not overlap, increasing the sealant's compression and further improving battery cell safety.

[0019] In some embodiments, the connecting portion includes a tab connecting segment and a fuse segment, the fuse segment is located between the tab connecting segment and the terminal body, and the tab connecting segment is used to connect the tab of the electrode assembly.

[0020] In the above solution, by providing a fuse section, the battery cell can be fused in time under external short-circuit conditions, and is not prone to fire and explosion, thereby improving the safety performance of the battery cell.

[0021] In some embodiments, the end cap assembly further includes a seal arranged around the terminal body, at least a portion of the seal is clamped between the end cap and the connecting portion, and in the thickness direction of the end cap, the projection of the seal does not overlap with the projection of the groove.

[0022] In this solution, the sealant enhances the seal between the end cap and the electrode terminal, reducing the likelihood of battery cell leakage and improving battery cell safety. The projection of the sealant and the projection of the groove in the thickness direction of the end cap do not overlap, increasing the sealant's compression and further improving battery cell safety.

[0023] In a second aspect, an embodiment of the present application provides a battery cell comprising a shell, an electrode assembly, and an end cap assembly of any of the above-mentioned embodiments, wherein the shell has an opening; the electrode assembly is accommodated in the shell; the end cap is used to cover the opening, and the connecting portion is located inside the battery cell.

[0024] In some embodiments, the electrode assembly has a tab, which is connected to the connecting portion, and at least part of the tab is accommodated in the groove, which not only reduces the weight of the battery cell, but also saves the space occupied by the tab and improves the energy density of the battery cell.

[0025] In some embodiments, the tab includes a horizontal section directly connected to the connecting portion. In the thickness direction of the end cap, the thickness of the horizontal section is less than or equal to the depth of the groove, which can further save the space occupied by the tab.

[0026] In a third aspect, an embodiment of the present application provides a battery comprising a battery cell according to any of the above embodiments.

[0027] In a fourth aspect, an embodiment of the present application provides an electrical device, comprising a battery cell according to any of the above embodiments, wherein the battery cell is used to provide electrical energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings without creative work.

[0029] FIG1 is a schematic diagram of a vehicle according to some embodiments of the present application;

[0030] FIG2 is a schematic structural diagram of a battery according to some embodiments of the present application;

[0031] FIG3 is a schematic structural diagram of the battery module shown in FIG2 ;

[0032] FIG4 is a schematic diagram of the exploded structure of a battery cell according to some embodiments of the present application;

[0033] FIG5 is a schematic cross-sectional view of a battery cell according to some embodiments of the present application;

[0034] FIG6 is a schematic structural diagram of a flip cover assembly according to some embodiments of the present application;

[0035] FIG7 is a schematic structural diagram of a connecting portion in some embodiments of the present application;

[0036] FIG8 is a schematic structural diagram of the connecting portion shown in FIG6 from another angle;

[0037] FIG9 is an enlarged schematic diagram of portion A shown in FIG8 ;

[0038] FIG10 is a schematic structural diagram of a connecting portion of other embodiments of the present application;

[0039] FIG11 is a schematic structural diagram of the connecting portion shown in FIG10 from another angle;

[0040] FIG12 is a schematic structural diagram of a connecting portion of yet other embodiments of the present application;

[0041] FIG13 is a schematic structural diagram of a connecting portion of some further embodiments of the present application;

[0042] FIG14 is a schematic structural diagram of the connecting portion shown in FIG13 from another angle;

[0043] FIG15 is a top view of a battery cell according to some embodiments of the present application;

[0044] FIG16 is a partial schematic diagram of a battery cell according to some embodiments of the present application.

[0045] In the drawings, the drawings are not drawn to scale.

[0046] Description of Figure Numbers:

[0047] Vehicle 1000; battery 100; controller 200; motor 300; housing 10; upper cover 10a; lower cover 10b; battery module 400; battery cell 20; shell 22; end cover 21; electrode terminal 26; electrode assembly 23; main body 231; tab 232; vertical section 232a; horizontal section 232b; end cover assembly 500; electrode lead-out hole 21a; connecting portion 30; groove 30a; first connecting sub-portion 31; second connecting sub-portion 32; tab connecting section 321; fuse section 322; through hole 32a; weight-reducing groove 30b; terminal body 40; seal 41; thickness direction X; first direction Y; second direction Z. DETAILED DESCRIPTION

[0048] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0049] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0050] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0051] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0052] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0053] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0054] The term "plurality" used in this application refers to two or more (including two).

[0055] In this application, battery cells may include lithium-ion secondary battery cells, lithium-ion primary battery cells, lithium-sulfur battery cells, sodium-lithium-ion battery cells, sodium-ion battery cells, or magnesium-ion battery cells, and the embodiments of this application are not limited thereto. Battery cells may be cylindrical, flat, rectangular, or in other shapes, and the embodiments of this application are not limited thereto.

[0056] In this application, battery cells may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, etc., and the embodiments of this application do not limit this. Battery cells may be cylindrical, flat, rectangular, or other shapes, etc., and the embodiments of this application do not limit this. Battery cells are generally divided into three types based on the packaging method: cylindrical battery cells, prismatic battery cells, and soft-pack battery cells, and the embodiments of this application do not limit this.

[0057] The battery referred to in the embodiments of this application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in this application may include a battery module or a battery pack. A battery generally includes a casing that encloses one or more battery cells. The casing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0058] A battery cell includes an electrode assembly and an electrolyte. The electrode assembly consists of a positive electrode sheet, a negative electrode sheet, and a separator. A battery cell primarily operates by the movement of metal ions between the positive and negative electrode sheets. The positive electrode sheet comprises a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector. The current collector uncoated with the positive active material layer protrudes from the current collector coated with the positive active material layer. The current collectors uncoated with the positive active material layer, when stacked, serve as the positive electrode tabs. For lithium-ion batteries, for example, the positive current collector can be made of aluminum, and the positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide. The negative electrode sheet comprises a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative current collector. The current collector uncoated with the negative active material layer protrudes from the current collector coated with the negative active material layer. The current collectors uncoated with the negative active material layer, when stacked, serve as the negative electrode tabs. The negative current collector can be made of copper, and the negative active material can be carbon, silicon, or other materials. The material of the isolation film may be PP (polypropylene) or PE (polyethylene), etc. In addition, the electrode assembly may be a wound structure or a laminated structure, but the embodiments of the present application are not limited thereto.

[0059] The inventors noted that electrode assemblies are typically electrically connected to end cap assemblies via tabs, which extract electrical energy from the electrode assemblies. Further research revealed that the connection structure between the end cap assembly and the electrode assembly of a battery cell requires internal space within the cell, reducing the cell's internal capacity and energy density.

[0060] In view of this, the present application provides a technical solution, in which an end cap assembly is used for a battery cell. The end cap assembly includes an end cap and an electrode terminal, wherein the end cap has an electrode lead-out hole. The electrode terminal includes a connecting portion and a terminal body, wherein the terminal body protrudes from the connecting portion and is at least partially accommodated in the electrode lead-out hole. The connecting portion is provided with a groove. In the above solution, the terminal body is accommodated in the electrode lead-out hole of the end cap, and electrical energy is led out through the terminal body. By providing a groove in the connecting portion, the tab or other components of the electrode terminal of the battery cell can be accommodated in the groove, which not only reduces the weight of the battery cell, but also saves the internal space of the battery cell, thereby improving the energy density of the battery cell.

[0061] The battery cells disclosed in the embodiments of this application can be used, but are not limited to, in electrical devices such as vehicles, ships, or aircraft. A power supply system comprising the battery cells and batteries disclosed in this application can be used to improve the stability of battery performance and battery life.

[0062] The present invention provides an electric device that uses a battery as a power source. The electric device may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery-powered vehicle, an electric car, a ship, a spacecraft, etc. The electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc. The spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0063] For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device according to an embodiment of the present application.

[0064] Please refer to Figure 1, which is a schematic structural diagram of a vehicle 1000 provided in some embodiments of the present application. The vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 can be provided at the bottom, head or tail of the vehicle 1000. The battery 100 can be used to power the vehicle 1000. For example, the battery 100 can serve as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0065] In some embodiments of the present application, the battery 100 can serve not only as an operating power source for the vehicle 1000, but also as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0066] Please refer to Figure 2, which is an exploded view of a battery 100 provided in some embodiments of the present application. The battery 100 includes a housing 10 and a battery cell 20. In some embodiments, the housing 10 may include an upper cover 10a and a lower cover 10b. The upper cover 10a and the lower cover 10b cover each other and together define a storage space for accommodating the battery cell 20. The lower cover 10b may be a hollow structure with one end open. The upper cover 10a may be a plate-like structure, and the upper cover 10a covers the open side of the lower cover 10b, so that the upper cover 10a and the lower cover 10b together define the storage space. The upper cover 10a and the lower cover 10b may also be hollow structures with one end open, with the open side of the upper cover 10a covering the open side of the lower cover 10b. Of course, the housing 10 formed by the upper cover 10a and the lower cover 10b can have various shapes, such as a cylinder, a rectangular parallelepiped, etc.

[0067] FIG3 is a schematic structural diagram of the battery module 400 shown in FIG2 . In the battery 100 , there may be multiple battery cells 20 , and the multiple battery cells 20 may be connected in series, in parallel, or in a mixed connection. Mixed connection means that the multiple battery cells 20 are both connected in series and in parallel. The multiple battery cells 20 may be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by the multiple battery cells 20 is accommodated in the case 10; of course, the battery 100 may also be in the form of a battery module 400 in which multiple battery cells 20 are first connected in series, in parallel, or in a mixed connection, and the multiple battery modules 400 are then connected in series, in parallel, or in a mixed connection to form a whole, and accommodated in the case 10. The battery 100 may also include other structures. For example, the battery 100 may also include a busbar component for achieving electrical connection between the multiple battery cells 20.

[0068] Each battery cell 20 may be a secondary battery or a primary battery, and may also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 20 may be cylindrical, flat, rectangular, or in other shapes.

[0069] Please refer to Figure 4, which is a schematic diagram of the exploded structure of a battery cell 20 provided in some embodiments of the present application. A battery cell 20 is the smallest unit that makes up a battery. A battery cell 20 includes a housing 21, an electrode assembly 22, and other functional components. An end cap 21 is a component that covers the opening of the housing 22 to isolate the internal environment of the battery cell 20 from the external environment. The shape of the end cap 21 can be adapted to the shape of the housing 22 to fit the housing 22. Optionally, the end cap 21 can be made of a material with a certain hardness and strength (such as aluminum alloy). This makes the end cap 21 less susceptible to deformation during compression and collision, providing the battery cell 20 with greater structural strength and improved safety. Functional components such as electrode terminals 26 can be provided on the end cap 21. The electrode terminals 26 can be used to electrically connect to the electrode assembly 23 to output or input electrical energy to the battery cell 20. In some embodiments, the end cap 21 can also be provided with a pressure relief mechanism to release internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold. The end cap 21 can be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, and plastic, and this embodiment of the present application does not impose any particular limitations thereon. In some embodiments, an insulating member can be disposed inside the end cap 21 to isolate the electrical connection components within the housing 22 from the end cap 21, thereby reducing the risk of short circuits. Exemplary materials include plastic, rubber, and the like.

[0070] The shell 21 is a component used to form the internal environment of the battery cell 20, wherein the formed accommodating cavity 21a can be used to accommodate the electrode assembly 22, electrolyte and other components. The shell 21 can be of various shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, a hexagonal prism, etc. Specifically, the shape of the shell 21 can be determined according to the specific shape and size of the electrode assembly 22. The material of the shell 21 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not impose any special restrictions on this.

[0071] The electrode assembly 22 is the component where the electrochemical reaction occurs in the battery cell 20. One or more electrode assemblies 22 may be contained in the housing 21. An insulating film 24 may be provided on the outer surface of the electrode assembly 22 to provide insulation protection between the battery cells 20. The electrode assembly 22 is mainly formed by winding or stacking the positive electrode sheet and the negative electrode sheet, and a separator is usually provided between the positive electrode sheet and the negative electrode sheet. The parts of the positive electrode sheet and the negative electrode sheet with active materials constitute the main body of the electrode assembly 22, and the parts of the positive electrode sheet and the negative electrode sheet without active materials each constitute a tab 232. The positive electrode tab and the negative electrode tab may be located together at one end of the main body or respectively at both ends of the main body.

[0072] Please refer to Figures 5 and 6 in combination. Figure 5 is a cross-sectional schematic diagram of a battery cell in some embodiments of the present application; Figure 6 is a structural schematic diagram of a flip cover assembly in some embodiments of the present application; on the first aspect, the embodiments of the present application provide an end cover assembly 500 for a battery cell 20, the end cover assembly 500 includes an end cover 21 and an electrode terminal 26, the end cover 21 has an electrode lead-out hole 21a; the electrode terminal 26 includes a connecting portion 30 and a terminal body 40, the terminal body 40 protrudes from the connecting portion 30 and is at least partially accommodated in the electrode lead-out hole 21a; the connecting portion 30 is provided with a groove 30a.

[0073] The groove 30a can be provided on the side of the connecting portion 30 facing the electrode assembly 23 of the battery cell 20, or on the side of the connecting portion 30 facing away from the electrode assembly 23, or on the side of the connecting portion 30, or on both the side of the connecting portion 30 facing the electrode assembly 23 and the side facing away from the electrode assembly 23. The shape of the groove 30a can be U-shaped, L-shaped, or annular, etc. The tab 232 of the electrode assembly 23 can be accommodated in the groove 30a to achieve electrical connection between the tab 232 and the connecting portion 30. An adapter can also be provided in the groove 30a, or both the adapter and the tab 232 can be accommodated in the groove 30a, with the tab 232 electrically connected to the connecting portion 30 via the adapter.

[0074] In the above scheme, the terminal body 40 is accommodated in the electrode lead-out hole 21a of the end cover 21, and the electric energy is led out to the outside of the battery cell 20 through the terminal body 40; by providing a groove 30a in the connecting portion 30, the tab 232 or other components of the battery cell 20 can be accommodated in the groove 30a, which not only reduces the weight of the battery cell 20, but also saves the internal space of the battery cell 20, thereby improving the energy density of the battery cell 20.

[0075] Please refer to Figures 7 to 9, Figure 7 is a structural schematic diagram of the connecting portion of some embodiments of the present application; Figure 8 is a structural schematic diagram of the connecting portion shown in Figure 6 from another angle; Figure 9 is an enlarged schematic diagram of portion A shown in Figure 8; in some embodiments, the connecting portion 30 includes a first connecting sub-portion 31 and a second connecting sub-portion 32, the second connecting sub-portion 32 is connected between the terminal body 40 and the first connecting sub-portion 31, and the thickness H1 of the second connecting sub-portion 32 is less than the thickness H2 of the first connecting sub-portion 31 to form a groove 30a.

[0076] The second connector 32 can be disposed on one or both sides of the first connector 31, in which case the groove 30a is L-shaped. Alternatively, the second connector 32 can be disposed around the first connector 31, in which case the groove 30a is annular. It should be noted that "the second connector 32 is connected between the terminal body 40 and the first connector 31" means that, along the thickness direction X of the end cap 21, the projection of the first connector 31 on the terminal body 40 at least partially overlaps, "the thickness H1 of the second connector 32" refers to the dimension of the second connector 32 along the thickness direction X of the end cap 21, and "the thickness H2 of the first connector 31" refers to the dimension of the first connector 31 along the thickness direction X of the end cap 21. The thickness H1 of the second connector 32 is less than the thickness H2 of the first connector 31, which is equivalent to thinning the area of ​​the second connector 32 of the connector 30 to form the groove 30a.

[0077] In the above solution, since the thickness of the second connecting sub-part 32 is less than that of the first connecting sub-part 31 , the terminal body 40 is connected to the thicker first connecting sub-part 31 , which can increase the connection strength between the terminal body 40 and the connecting part 30 and improve the stability of the terminal body 40 .

[0078] In some embodiments, a groove 30a is provided on the surface of the connecting portion 30 facing the electrode assembly 23 of the battery cell 20. The groove 30a can be provided on the side of the connecting portion 30, or in the middle or other areas of the connecting portion 30. Since the tab 232 is located on the side of the electrode assembly 23 facing the end cap assembly 500, the tab 232 can be bent and directly accommodated in the groove 30a and connected to the second connecting sub-portion 32, or after the adapter is accommodated in the groove 30a, the tab 232 is connected to the electrode terminal 26 through the adapter. The groove 30a is provided on the surface of the connecting portion 30 facing the electrode assembly 23 of the battery cell 20, so there is no need to bypass the tab 232 around the connecting portion 30 and connect it to the side of the connecting portion 30 facing away from the electrode assembly 23, which facilitates the tab 232 or other components of the electrode assembly 23 to be accommodated in the groove 30a, facilitates process preparation, and improves production efficiency.

[0079] In some embodiments, the surface of the first connecting sub-portion 31 facing the end cap 21 is flush with the surface of the second connecting sub-portion 32 facing the end cap 21. That is, the groove 30a is not provided on the side of the connecting portion 30 facing away from the electrode assembly 23, but is provided on the side of the connecting portion 30 facing the electrode assembly 23.

[0080] In the above solution, the surface of the connecting portion 30 facing the end cover 21 is a flat surface, which can improve the bearing capacity of the connecting portion 30 on the end cover 21 and enhance the strength of the end cover assembly 500 .

[0081] Optionally, the second connecting sub-portion 32 is recessed toward the end cover 21 to form a groove 30 a.

[0082] In some embodiments, in the thickness direction X of the end cap 21, the thickness of the second connector 32 is H1, and the thickness of the first connector 31 is H2. Thus, 1 / 5H2≤H1≤4 / 5H2. If the thickness of the second connector 32 is too small, the structural strength of the second connector 32 will be affected. If the thickness of the second connector 32 is too large, the space for accommodating the tab 232 or the adapter will be reduced, the internal space of the battery cell 20 will not change much, and the energy density will be limited.

[0083] In the above solution, the thickness of the second connecting sub-portion 32 is moderate, which can reduce the weight and internal capacity of the battery cell 20 while ensuring the strength of the second connecting sub-portion 32 .

[0084] Please refer to Figures 10 and 11 in combination. Figure 10 is a structural schematic diagram of the connecting portion of other embodiments of the present application; Figure 11 is a structural schematic diagram of the connecting portion shown in Figure 10 from another angle; in some embodiments, the first connecting sub-portion 31 and the second connecting sub-portion 32 are arranged along the first direction Y; in the second direction Z, at least one end of the second connecting sub-portion 32 extends beyond the first connecting sub-portion 31, and the first direction Y, the second direction Z and the thickness direction X of the end cover 21 are perpendicular to each other.

[0085] Any end of the second connecting sub-portion 32 along the second direction Z may extend beyond the first connecting sub-portion 31 , or both opposite ends of the second connecting sub-portion 32 along the second direction Z may extend beyond the first connecting sub-portion 31 , so that a gap is formed between the first connecting sub-portion 31 and the second connecting sub-portion 32 .

[0086] In the above solution, at least one end of the second connecting sub-portion 32 extends beyond the first connecting sub-portion 31 , which can further reduce the weight of the connecting portion 30 , further save the internal space of the battery cell 20 , and improve the energy density of the battery cell 20 .

[0087] In some embodiments, there are two second connecting sub-portions 32, and the two second connecting sub-portions 32 are respectively located on both sides of the first connecting sub-portion 31 along the first direction Y; the electrode terminal 26 is provided with a weight-reducing groove 30b, which is located on one side of the first connecting sub-portion 31 along the second direction Z and is surrounded by the first connecting sub-portion 31 and the two second connecting sub-portions 32.

[0088] In the thickness direction X along the end cover 21, the projection of the weight-reducing groove 30b may not overlap with the projection of the second connecting sub-part 32. The weight-reducing groove 30b is equivalent to being formed by digging a hole at the end of the first connecting sub-part 31 along the second direction Z. Of course, the projection of the weight-reducing groove 30b may also overlap with the projection part of one of the second connecting sub-parts 32, or overlap with the projection parts of the two second connecting sub-parts 32 respectively.

[0089] In the above solution, the two second connecting sub-portions 32 are located on either side of the first connecting sub-portion 31 along the first direction Y, allowing a single end cap assembly 500 to simultaneously connect to two electrode assemblies 23, thereby improving the energy density of the battery cell 20. The weight-reducing groove 30b, enclosed by the first connecting sub-portion 31 and the two second connecting sub-portions 32, not only reduces the weight of the end cap assembly 500, conserves internal space in the battery cell 20, further improving the energy density of the battery cell 20, but also provides more connection space for components connected to the second connecting sub-portions 32.

[0090] In other embodiments, the weight-reducing groove 30 b may not be formed at the end of the connecting portion 30 , but may be disposed in the middle or other areas of the connecting portion 30 .

[0091] Figure 12 is a structural schematic diagram of the connecting portion of some other embodiments of the present application. As shown in Figure 12, in some embodiments, the end cover assembly 500 also includes a seal 41 arranged around the terminal body 40, and at least part of the seal 41 is clamped between the end cover 21 and the connecting portion 30. In the thickness direction X of the end cover 21, the projection of the weight-reducing groove 30b does not overlap with the projection of the seal 41.

[0092] The seal 41 can be made of a compressible material such as rubber or foam. The seal 41 is compressed and positioned between the end cap 21 and the connecting portion 30. This seal 41 enhances the seal between the end cap 21 and the electrode terminal 26, reduces the likelihood of leakage from the battery cell 20, and improves the safety of the battery cell 20. In the thickness direction X of the end cap 21, the projection of the lightening groove 30b does not overlap with the projection of the seal 41. In other words, the seal 41 is not positioned in the portion of the connecting portion 30 corresponding to the lightening groove 30b. This increases the compression of the seal 41 and further improves the safety of the battery cell 20.

[0093] Figure 13 is a structural schematic diagram of the connection part of some other embodiments of the present application; Figure 14 is a structural schematic diagram of the connection part shown in Figure 13 from another angle; please refer to Figure 13 and Figure 14 in combination. In some embodiments, the connection part 30 includes a tab connection section 321 and a fuse section 322, and the fuse section 322 is located between the tab connection section 321 and the terminal body 40. The tab connection section 321 is used to connect the tab 232 of the electrode assembly 23.

[0094] The fuse section 322 is located on the side of the second connecting sub-section 32 near the first connecting sub-section 31. By providing a through hole 32a on the side of the second connecting sub-section 32 near the first connecting sub-section 31, the portion of the second connecting sub-section 32 corresponding to the through hole 32a along the second direction Z constitutes the fuse section 322. Because the length L1 of the fuse section 322 along the second direction Z is less than the length L2 of the tab connecting section 321 along the second direction Z, the flow area of ​​the fuse section 322 is reduced, making it easier for the fuse section 322 to blow. It is understood that the through hole 32a can be directly provided at the end of the second connecting sub-section 32 along the second direction Z to facilitate manufacturing, and the through hole 32a can be provided at both ends of the second connecting sub-section 32 along the second direction Z. Of course, the through hole 32a can also be provided in the middle or other area of ​​the second connecting sub-section 32 near the first connecting sub-section 31, and the number of through holes 32a can be one or more.

[0095] The tab 232 can be directly welded to the tab connecting section 321 or connected to the tab connecting section 321 via an adapter.

[0096] In the above solution, by providing the fuse section 322 , the battery cell 20 can be fused in time under external short circuit conditions, and is less likely to catch fire or explode, thereby improving the safety performance of the battery cell 20 .

[0097] In some embodiments, the end cover assembly 500 also includes a seal 41 arranged around the terminal body 40, at least part of the seal 41 is clamped between the end cover 21 and the connecting portion 30, and in the thickness direction X of the end cover 21, the projection of the seal 41 does not overlap with the projection of the groove 30a.

[0098] As an example, the groove 30 a is provided on a side of the second connecting sub-portion 32 facing away from the end cover, and the projection of the sealing member 41 does not overlap with the projection of the second connecting sub-portion 32 .

[0099] The seal 41 can be made of a compressible material such as rubber or foam. The seal 41 is compressed and disposed between the end cap 21 and the connecting portion 30 . This enhances the seal between the end cap 21 and the electrode terminal 26 , reduces the likelihood of leakage from the battery cell 20 , and improves the safety of the battery cell 20 .

[0100] In the thickness direction X of the end cover 21, the projection of the seal 41 does not overlap with the projection of the groove 30a, that is, the seal 41 is not arranged in the portion of the connecting portion 30 corresponding to the groove 30a. The seal 41 is pressed by the thicker portion of the connecting portion 30, which can increase the compression amount of the seal 41, further reduce the probability of leakage of the battery cell 20, and improve the safety performance of the battery cell 20.

[0101] Optionally, in the thickness direction X of the end cover 21 , the projection of the sealing member 41 falls within the projection range of the first connecting sub-portion 31 , and the sealing member 41 is clamped between the end cover 21 and the first connecting sub-portion 31 .

[0102] On the second aspect, an embodiment of the present application provides a battery cell 20, including a shell 22, an electrode assembly 23 and an end cover assembly 500 of any of the above-mentioned embodiments, the shell 22 has an opening; the electrode assembly 23 is accommodated in the shell 22; the end cover 21 is used to cover the opening, and the connecting part 30 is located inside the battery cell 20.

[0103] As shown in Figure 15, which is a top view of a battery cell according to some embodiments of the present application, in some embodiments, the electrode assembly 23 includes a tab 232 connected to the connecting portion 30, with at least a portion of the tab 232 being accommodated within the recess 30a. The tab 232 can be partially or fully accommodated within the recess 30a, which not only reduces the weight of the battery cell 20 but also saves space occupied by the tab 232, thereby increasing the energy density of the battery cell 20.

[0104] As shown in Figure 16, which is a partial schematic diagram of a battery cell in some embodiments of the present application, in some embodiments, the tab 232 includes a horizontal segment 232b directly connected to the connecting portion 30. Along the thickness direction X of the end cap 21, the thickness of the horizontal segment 232b is less than or equal to the depth of the groove 30a.

[0105] The electrode assembly 23 includes a main body 231 and a pole ear 232. After the pole ear 232 is bent, the pole ear 232 includes a vertical section 232a and a horizontal section 232b. The vertical section 232a extends from the main body 231 toward the end cover 21, and the horizontal section 232b is bent from the vertical section 232a along the first direction Y and toward the direction close to the first connecting sub-section 31, connecting the horizontal section 232b to the second connecting sub-section 32.

[0106] In the above solution, the tab 232 is bent to form the horizontal section 232b, which saves space compared to connecting the tab 232 to the connecting portion 30 without bending the tab 232. Moreover, directly connecting the horizontal section 232b to the connecting portion 30 eliminates the need for an adapter, further saving space and reducing costs.

[0107] In a third aspect, an embodiment of the present application provides a battery 100 comprising a battery cell 20 according to any of the above embodiments.

[0108] In a fourth aspect, an embodiment of the present application provides an electrical device, comprising a battery cell 20 according to any of the above embodiments, wherein the battery cell 20 is used to provide electrical energy.

[0109] According to some embodiments of the present application, an end cap assembly 500 is provided for use with a battery cell 20. The end cap assembly 500 includes an end cap 21 and an electrode terminal 26. The end cap 21 has an electrode lead-out hole 21a. The electrode terminal 26 includes a connecting portion 30 and a terminal body 40. The terminal body 40 protrudes from the connecting portion 30 and is at least partially accommodated in the electrode lead-out hole 21a. The connecting portion 30 has a groove 30a defined on a surface facing the electrode assembly 23 of the battery cell 20. The tab 232 is accommodated in the groove 30a and directly connected to the second connecting sub-portion 32. The connecting portion 30 includes a first connecting sub-portion 31 and a second connecting sub-portion 32. The second connecting sub-portion 32 is connected between the terminal body 40 and the first connecting sub-portion 31. The thickness H1 of the second connecting sub-portion 32 is less than the thickness H2 of the first connecting sub-portion 31 to form the groove 30a.

[0110] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0111] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An end cap assembly for a battery cell, characterized in that: include: an end cap having an electrode lead-out hole; an electrode terminal comprising a connecting portion and a terminal body, wherein the terminal body protrudes from the connecting portion and is at least partially accommodated in the electrode lead-out hole; The connecting portion is provided with a groove.

2. The end cap assembly according to claim 1, wherein: The connecting portion includes a first connecting sub-portion and a second connecting sub-portion, the second connecting sub-portion is connected between the terminal body and the first connecting sub-portion, and a thickness of the second connecting sub-portion is smaller than that of the first connecting sub-portion to form the groove.

3. The end cap assembly according to claim 2, wherein: The groove is provided on a surface of the connecting portion facing the electrode assembly of the battery cell.

4. The end cap assembly according to claim 3, wherein: A surface of the first connecting sub-part facing the end cap is flush with a surface of the second connecting sub-part facing the end cap.

5. The end cap assembly according to any one of claims 2 to 4, characterized in that: In the thickness direction of the end cover, the thickness of the second connecting sub-part is H1, and the thickness of the first connecting sub-part is H2, then 1 / 5 H2≤H1≤4 / 5 H2.

6. The end cap assembly according to any one of claims 2 to 4, characterized in that: The first connecting sub-part and the second connecting sub-part are arranged along a first direction; in a second direction, at least one end of the second connecting sub-part exceeds the first connecting sub-part, and the first direction, the second direction and the thickness direction of the end cover are perpendicular to each other.

7. The end cap assembly according to claim 6, wherein: There are two second connecting sub-parts, and the two second connecting sub-parts are respectively located on both sides of the first connecting sub-part along the first direction; the electrode terminal is provided with a weight-reducing groove, and the weight-reducing groove is located on one side of the first connecting sub-part along the second direction and is surrounded by the first connecting sub-part and the two second connecting sub-parts.

8. The end cap assembly according to claim 7, wherein: The end cover assembly also includes a seal arranged around the terminal body, at least part of the seal is clamped between the end cover and the connecting portion, and in the thickness direction of the end cover, the projection of the weight reduction groove does not overlap with the projection of the seal.

9. The end cap assembly according to any one of claims 1 to 8, characterized in that: The connecting portion includes a tab connecting section and a fuse section. The fuse section is located between the tab connecting section and the terminal body. The tab connecting section is used to connect the tab of the electrode assembly.

10. The end cap assembly according to any one of claims 1 to 9, characterized in that: The end cover assembly further includes a seal arranged around the terminal body, at least a portion of the seal is clamped between the end cover and the connecting portion, and in the thickness direction of the end cover, the projection of the seal does not overlap with the projection of the groove.

11. A battery cell, characterized in that: include: a housing having an opening; an electrode assembly, housed in the housing; as well as The end cover assembly according to any one of claims 1 to 10, wherein the end cover is used to cover the opening, and the connecting portion is located inside the battery cell.

12. The battery cell according to claim 11, characterized in that The electrode assembly has a tab connected to the connecting portion, and at least a portion of the tab is accommodated in the groove.

13. The battery cell according to claim 12, characterized in that: The tab includes a horizontal section directly connected to the connecting portion, and along the thickness direction of the end cover, the thickness of the horizontal section is less than or equal to the depth of the groove.

14. A battery, characterized in that: The invention comprises the battery cell according to any one of claims 11 to 13.

15. An electrical device, characterized in that: The invention comprises the battery cell according to any one of claims 11 to 13, wherein the battery cell is used to provide electric energy.

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