End cover assembly, battery monomer, battery and electric device

Abstract

The utility model discloses an end cover assembly, a battery monomer, a battery and a power utilization device. The end cover assembly provided by the embodiment of the utility model comprises an end cover which is provided with a first through hole; the electrode leading-out piece comprises a connecting plate and a pole terminal protruding out of the surface of the connecting plate, at least part of the pole terminal is arranged in the first through hole, the connecting plate is located on one side of the end cover, and the connecting plate is used for being connected with a tab of the electrode assembly. In the technical scheme of the embodiment of the invention, the electrode lead-out piece is arranged, so that the contact area of the pole and the tab is increased, the overcurrent area of the pole terminal and the connecting plate is enlarged, the internal resistance is reduced, the temperature rise is reduced, and the safety performance of the battery monomer is improved.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the priority of Chinese patent application No. 202210929978.0, entitled “END CAP ASSEMBLY, BATTERY STATE, BATTERY AND ELECTRICAL DEVICE” filed on August 4, 2022, the entire contents of which are incorporated herein by reference Technical Field

[0003] The present application relates to the field of batteries, and in particular to an end cover assembly, a battery cell, a battery, and an electrical device. Background Art

[0004] Batteries are widely used in electronic devices, such as mobile phones, laptop computers, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and electric tools, etc. Batteries can include nickel-cadmium batteries, nickel-hydrogen batteries, lithium-ion batteries, and secondary alkaline zinc-manganese batteries, etc.

[0005] In the development of battery technology, in addition to improving battery performance, how to improve battery safety and improve battery installation efficiency is also one of the research focuses in this field. Summary of the invention

[0006] In view of the above problems, the present application provides an end cover assembly, a battery cell, a battery and an electrical device, which can solve the problem of improving the safety performance of the battery and increasing the efficiency of the battery.

[0007] In a first aspect, the present application provides an end cap assembly, comprising: an end cap and an electrode lead-out member. The end cap is provided with a first through hole. The electrode lead-out member comprises a connecting plate and a pole terminal protruding from a surface of the connecting plate, at least a portion of the pole terminal is provided in the first through hole, and the connecting plate is located on one side of the end cap, wherein the connecting plate is used to connect a pole ear of the electrode assembly.

[0008] In the technical solution of the embodiment of the present application, the pole terminal is arranged in the electrode lead-out piece, which expands the flow area between the pole terminal and the connecting plate, reduces the internal resistance, reduces the temperature rise, and improves the safety performance of the battery cell.

[0009] In some embodiments, the connection plate and the pole terminal are an integrally formed structure, and the connection plate is provided with a welding area, which is used to connect the pole lug. The above structure sets the connection plate and the pole terminal as an integrally formed structure, which improves the connection stability between the pole terminal and the connection plate, and the convenience of assembly. In addition, by setting a welding area on the connection plate, the connection plate is connected to the pole lug, which improves the connection stability.

[0010] In some embodiments, the pole terminal includes a main body extending in the thickness direction of the end cover and a first protrusion protruding from the peripheral side of the main body in the radial direction of the main body, and at least a portion of the first protrusion is disposed in the first through hole. In the above technical solution, the first protrusion is provided to reduce the gap between the pole terminal and the end cover, thereby improving the stability of the pole terminal.

[0011] In some embodiments, the first protrusion surrounds the main body.

[0012] The end cap assembly further comprises a sealing member at least partially arranged around the outer periphery of the first protrusion, and at least a portion of the sealing member is arranged in the first through hole. In the above technical solution, the sealing member is arranged to achieve insulation between the pole terminal and the end cap.

[0013] In some embodiments, the end cover assembly further includes: a terminal plate, disposed on a side of the end cover away from the connecting plate and connected to the pole terminal; an insulating member, disposed around the pole terminal, at least a portion of the insulating member being disposed between the terminal plate and the end cover.

[0014] The pole terminal is fixed by arranging a terminal plate, and an insulating member is arranged to achieve insulation between the pole terminal and the end cover, thereby preventing the electric energy leakage of the battery cell.

[0015] In some embodiments, a second through hole is provided on the terminal board, the terminal board includes an annular first clamping portion protruding from the wall of the second through hole, and the pole terminal also includes an annular second protrusion protruding along the outer peripheral surface of the main body, the second protrusion is spaced apart from the first protrusion, wherein the first clamping portion is clamped between the first protrusion and the second protrusion.

[0016] By providing the first clamping portion and the second convex portion, the pole terminal and the terminal board are clamped and connected, thereby increasing the flow area between the terminal board and the pole terminal and improving the safety of the battery cell.

[0017] In some embodiments, the insulating member includes a body and a blocking portion, at least a portion of the body is disposed between the terminal board and the end cover, the blocking portion protrudes from a side of the body away from the terminal board, extends into the first through hole and is disposed between the end cover and the pole terminal.

[0018] By arranging the blocking portion to extend into the first through hole and to be arranged between the end cover and the pole terminal, the insulation performance between the terminal plate and the pole terminal is improved.

[0019] In some embodiments, the blocking portion extends axially along the first through hole and abuts against the sealing member. The above mechanism further enhances the barrier between the end cover and the pole terminal, thereby improving the insulation effect.

[0020] In some embodiments, the seal includes a sealing portion disposed between the pole terminal and the end cover and a connecting portion surrounding the outer periphery of the sealing portion, and at least a portion of the connecting portion is disposed between the end cover and the connecting plate. In the above structure, the connecting portion is disposed between the end cover and the connecting plate, thereby achieving insulation between the end cover and the connecting plate.

[0021] In some embodiments, the connecting plate includes an extension portion extending outward from one side of the connecting plate along the length direction or the width direction of the end cover. The extension portion is provided to increase the area of ​​the tab welding and improve the efficiency and stability of the connection.

[0022] In some embodiments, along the length direction of the end cap, the distance from the axis of the pole terminal to the geometric center of the connecting plate is greater than 0. By eccentrically arranging the pole terminal on the connecting plate, the space in the end cap assembly can be fully utilized to arrange the connecting plate, thereby increasing the area of ​​the connecting plate and improving the stability of the connection between the pole lug and the connecting plate.

[0023] In some embodiments, the extension portion extends from one side of the connection plate along the length direction of the end cap. In the length direction of the end cap, the connection plate includes a first edge and a second edge that are arranged opposite to each other, the first edge is located at the extension portion, and the distance from the first edge to the axis of the pole terminal is greater than the distance from the second edge to the axis of the pole terminal, so that the connection plate is eccentrically arranged relative to the pole terminal. By eccentrically arranging the connection plate relative to the pole terminal, the space between the electrode assembly and the end cap can be effectively utilized, the welding area of ​​the pole lug can be increased, the stability of the pole lug connection can be ensured, the flow area can be increased, the internal resistance and temperature rise can be reduced, and the stability and safety of the battery cell can be improved.

[0024] In some embodiments, a first weight-reducing portion is provided on the extension portion, and the thickness of the first weight-reducing portion is less than the thickness of the connecting plate. The first weight-reducing portion is provided to effectively reduce the weight of the extension portion and improve the energy density of the battery cell.

[0025] In some embodiments, the edge of the connecting plate is concave to form a second weight-reducing portion. The above technical solution has a simple structure and is easy to implement.

[0026] In some embodiments, the edge of the extension portion is concave to form a third weight-reducing portion. The above technical solution has a simple structure and is easy to implement.

[0027] In some embodiments, the minimum distance H2 between the third weight-reducing portion and the pole terminal satisfies H2≥2 mm. By setting the range of the minimum distance between the third weight-reducing portion and the pole terminal, the overall weight of the electrode lead-out member is reduced while ensuring the flow area of ​​the connection plate, thereby improving the energy density of the battery cell.

[0028] In some embodiments, along the width direction of the end cap, the extension length L1 of the connecting plate, the extension length L2 of the third weight-reducing portion, and the extension length L3 of the welding zone satisfy the relationship: L2≤L1-2(L3+3), where the calculation units of L1, L2, and L3 are millimeters. The above technical solution can ensure the welding area of ​​the welding zone on the connecting plate, and at the same time, reduce the weight of the connecting plate, achieving the technical effect of reasonable weight reduction and improving the energy density of the battery cell.

[0029] In some embodiments, the end cap assembly further includes an insulating plate, a third through hole is provided on the insulating plate, at least a portion of the pole terminal is provided in the third through hole, and the insulating plate is provided on a side of the end cap facing the electrode assembly, and at least a portion of the insulating plate is provided between the connecting plate and the end cap. By providing the insulating plate, an insulation effect between the end cap and the electrode assembly is achieved.

[0030] In some embodiments, the edges of the insulating plate on opposite sides extend toward the electrode assembly to form convex portions. The convex portions are arranged on both sides of the insulating plate to define an accommodation space between the end cap assembly and the electrode assembly, facilitate the arrangement of the connecting plate, and further ensure the safety of the battery cell.

[0031] In some embodiments, the maximum distance from the projection of the protrusion on the end cap to the edge of the end cap is C, C ≥ 8.5 mm. The above distance C determines the extension length of the protrusion in the length direction of the end cap. Excluding the thickness of the end cap edge of 1.5 mm, the extension length of the protrusion in the length direction of the end cap is greater than or equal to 7 mm. When the extension length of the protrusion is too small, it is possible to cut the electrode assembly and cause damage to the electrode assembly. Therefore, setting a reasonable extension length of the protrusion can ensure the safety performance of the electrode assembly.

[0032] In some embodiments, the extension length of the connecting plate in the width direction of the end cap is C1 (D6), the number of welding areas is two, the two welding areas are arranged along the width direction of the end cap, and the maximum distance between the two welding areas in the width direction of the end cap is A1, C1 ≥ A1 + 4mm. The above technical solution sets a reasonable length of the non-welding area on the connecting plate, reserves sufficient margin for the process of pressing the electrode assembly, ensures the smooth assembly process of the electrode assembly, and improves the safety performance of the battery cell.

[0033] In some embodiments, in the length direction of the end cap, the extension length of the welding area is D1, the extension length of the pole ear is D3, the pole ear is the positive pole ear, and the extension length of the connecting plate is D2, D3≥D2≥D1+4mm. In the above structure, the length of the pole ear is greater than the length of the connecting plate, which can improve the convenience of the pole ear connection, while reducing the space and weight occupied by the connecting plate, ensuring the energy density of the battery cell. In addition, the length of the connecting plate is greater than the length of the welding area, which reserves sufficient margin for the process of pressing the electrode assembly, ensuring the smooth assembly process of the electrode assembly, and improving the safety performance of the battery cell.

[0034] In some embodiments, in the length direction of the end cap, the maximum distance between the orthographic projections of the edges of the two tabs on the end cap is D4, and D1 ≥ (D3-2D4) / 0.8. The length of the above-mentioned welding zone is set by comprehensively considering the maximum misalignment between the tabs and the length of each tab, so as to ensure that each tab in the stacked arrangement can be stably connected to the connecting plate.

[0035] In some embodiments, an injection hole is further provided on the end cover, the distance between the center of the injection hole and the edge of the end cover is D5, the distance between the center of the pole terminal and the edge of the end cover is A2, the pole terminal is a positive pole terminal, and the minimum distance between the center of the pole terminal and the center line of the connecting plate is A3, D5-0.5D2-A2-3mm≥A3≥A+D4+0.5D3-A2.

[0036] The above technical solution comprehensively considers the location of the injection hole, the eccentric distance between the pole terminal and the connecting plate, and the maximum misalignment of the two positive pole ears, so as to reasonably set the diameter of the positive pole terminal, reduce the probability of interference between the positive pole terminal and the injection hole, and ensure that the connecting plate does not exceed the edge of the end cover.

[0037] In some embodiments, there are two electrode lead-out members, namely a first electrode lead-out member and a second electrode lead-out member, a pressure relief mechanism is further provided between the first electrode lead-out member and the second electrode lead-out member, the first electrode lead-out member includes a first connecting plate and a first pole terminal, the second electrode lead-out member includes a second connecting plate and a second pole terminal,

[0038] The length of the end cover is L2, the extension length of the pressure relief mechanism in the length direction of the end cover is L3, the minimum distance from the center line of the first connecting plate to the edge of the end cover is A5, the minimum distance from the center of the first pole terminal to the center line of the first connecting plate is A6, the extension length of the second pole ear in the length direction of the end cover is L4, and in the length direction of the end cover, the maximum distance between the orthographic projections of the edges of the two second pole ears on the end cover is D6, 0.5(L2-L3)-A5-0.5L4-3mm≥A6≥A+L4+0.5D6-A5.

[0039] The above technical solution comprehensively considers the length of the end cap, the extension length of the pressure relief mechanism, the length of the pole ear, and the maximum misalignment of the plurality of second pole ears to set a reasonable diameter of the second pole terminal, reduce the probability of interference between the second pole terminal and the pressure relief mechanism, and at the same time, the second connecting plate does not exceed the edge of the end cap. In a second aspect, the present application also provides a battery cell, including the end cap assembly in the above embodiment.

[0040] In a third aspect, the present application also provides a battery, comprising the battery cell in the above embodiment.

[0041] In a fourth aspect, the present application further provides an electrical device, which includes the battery in the above embodiment, and the battery is used to provide electrical energy.

[0042] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The features, advantages and technical effects of exemplary embodiments of the present application will be described below with reference to the accompanying drawings.

[0044] Figure 1 A schematic diagram of the structure of a vehicle provided in some embodiments of the present application;

[0045] Figure 2 An exploded schematic diagram of a battery provided in some embodiments of the present application;

[0046] Figure 3 An exploded schematic diagram of a battery cell in a battery provided in some embodiments of the present application;

[0047] Figure 4 An exploded schematic diagram of an end cap assembly in a battery provided in some embodiments of the present application;

[0048] Figure 5 A schematic diagram of the structure of an electrode lead-out member of an end cap assembly provided in some embodiments of the present application;

[0049] Figure 6 A schematic cross-sectional view of an electrode lead-out member provided in some embodiments of the present application;

[0050] Figure 7 A schematic cross-sectional view of an end cap assembly provided in some embodiments of the present application;

[0051] Figure 8 for Figure 7 An enlarged schematic diagram of the circle A in FIG.

[0052] Fig. 9 A bottom view of an electrode lead-out member provided in some embodiments of the present application;

[0053] Fig.10 A schematic diagram of the structure of electrode lead-out members provided in other embodiments of the present application;

[0054] Fig.11 A schematic diagram of the structure of electrode lead-out members provided in some other embodiments of the present application;

[0055] Fig.12 A bottom view of an electrode lead-out member provided in some other embodiments of the present application;

[0056] Fig.13 A schematic diagram of the structure of electrode lead-out members provided in some other embodiments of the present application;

[0057] Fig.14 A schematic diagram of the structure of an end cap assembly provided in some embodiments of the present application;

[0058] Fig.15 for Fig.14 Schematic diagram of the cross-sectional structure of the middle BB section;

[0059] Fig.16 for Fig.15 An enlarged schematic diagram of the middle circle D;

[0060] Fig.17 for Fig.15 An enlarged schematic diagram of the middle circle E.

[0061] In the drawings, the drawings are not necessarily drawn to scale.

[0062] Description of reference numerals:

[0063] 1. Vehicle; 2. Battery; 21. Opening; 24. Pressure relief mechanism; 25. Electrode terminal; 3. Controller; 4. Motor; 5. Housing; 51. First part; 52. Second part; 53. Accommodation space; 30. End cover assembly; 301. End cover; 302. Electrode lead-out member; 303. First through hole; 304. Connecting plate; 305. Post terminal; 306. Main body; 307. First convex portion; 308. Seal; 309. Terminal board; 310. Insulator; 311. Second through hole; 312. First clamping portion; 313. Second convex portion; 314. Main body; 315. Blocking portion; 316. Welding area; 317. Extension portion; 318. First weight-reducing portion; 319. Second weight-reducing portion; 320. Third weight-reducing portion; 321. Insulating plate; 322. Third through hole; 323. Convex portion. DETAILED DESCRIPTION

[0064] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0065] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. 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 and secondary relationship.

[0066] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0067] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0068] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0069] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0070] The term "plurality" used in the present application refers to two or more (including two).

[0071] In the present application, battery cells may include lithium-ion secondary battery cells, lithium-ion primary battery cells, lithium-sulfur battery cells, sodium-lithium-ion battery cells, sodium-ion battery cells or magnesium-ion battery cells, etc., and the embodiments of the present application do not limit this. Battery cells may be cylindrical, flat, rectangular or other shapes, etc., and the embodiments of the present application do not limit this. Battery cells are generally divided into three types according to the packaging method: cylindrical battery cells, square battery cells and soft-pack battery cells, and the embodiments of the present application do not limit this.

[0072] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in the present application may include a battery module or a battery pack. The battery generally includes a housing for encapsulating one or more battery cells. The housing can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cells.

[0073] A battery cell includes an electrode unit and an electrolyte. The electrode unit includes at least one electrode assembly. The electrode assembly includes a positive electrode sheet, a negative electrode sheet, and a separator. A battery cell mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. The positive electrode sheet includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector. The positive current collector includes a positive current collector and a positive convex portion protruding from the positive current collector. The positive current collector is coated with a positive active material layer. At least part of the positive convex portion is not coated with the positive active material layer. The positive convex portion serves as a positive electrode ear. Taking a lithium-ion battery as an example, the material of the positive current collector may be aluminum. The positive active material layer includes a positive active material. The positive active material may be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer, and the negative electrode active material layer is coated on the surface of the negative electrode current collector; the negative electrode current collector includes a negative electrode current collector and a negative electrode protrusion protruding from the negative electrode current collector, the negative electrode current collector is coated with a negative electrode active material layer, at least part of the negative electrode protrusion is not coated with the negative electrode active material layer, and the negative electrode protrusion serves as a negative electrode tab. The material of the negative electrode current collector may be copper, and the negative electrode active material layer includes a negative electrode active material, and the negative electrode active material may be carbon or silicon, etc. In order to ensure that a large current passes without melting, the number of positive electrode tabs is multiple and stacked together, and the number of negative electrode tabs is multiple and stacked together. The material of the separator may be PP (polypropylene, polypropylene) or PE (polyethylene, polyethylene), etc. In addition, the electrode assembly may be a winding structure or a laminated structure, and the embodiments of the present application are not limited thereto.

[0074] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[0075] Figure 1 This is a schematic diagram of the structure of a vehicle provided in some embodiments of the present application. Figure 1 As shown, a battery 2 is disposed inside the vehicle 1, and the battery 2 may be disposed at the bottom, head, or tail of the vehicle 1. The battery 2 may be used to power the vehicle 1, for example, the battery 2 may be used as an operating power source for the vehicle 1.

[0076] The vehicle 1 may further include a controller 3 and a motor 4 , wherein the controller 3 is used to control the battery 2 to supply power to the motor 4 , for example, to meet the power requirements of starting, navigating, and driving the vehicle 1 .

[0077] In some embodiments of the present application, the battery 2 can not only serve as an operating power source for the vehicle 1, but also serve as a driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0078] Figure 2 Schematic diagram of an explosion of a battery provided in some embodiments of the present application. Figure 2 As shown, the battery 2 includes a housing 5 and a battery module 6 . A plurality of battery cells constitute the battery module 6 , and the battery module 6 is accommodated in the housing 5 .

[0079] The housing 5 is used to accommodate the battery cell, and the housing 5 can be of various structures. In some embodiments, the housing 5 can include a first part 51 and a second part 52, the first part 51 and the second part 52 cover each other, and the first part 51 and the second part 52 jointly define a storage space 53 for accommodating the battery cell. The second part 52 can be a hollow structure with one end open, the first part 51 is a plate-like structure, and the first part 51 covers the open side of the second part 52 to form a housing 5 with a storage space 53; the first part 51 and the second part 52 can also be hollow structures with one side open, and the open side of the first part 51 covers the open side of the second part 52 to form a housing 5 with a storage space 53. Of course, the first part 51 and the second part 52 can be of various shapes, such as a cylinder, a cuboid, etc.

[0080] In order to improve the sealing performance after the first part 51 and the second part 52 are connected, a sealing member, such as a sealant, a sealing ring, etc., may also be provided between the first part 51 and the second part 52 .

[0081] Assuming that the first portion 51 covers the top of the second portion 52 , the first portion 51 can also be referred to as an upper box cover, and the second portion 52 can also be referred to as a lower box body.

[0082] In the battery 2, there can be one or more battery cells. If there are more than one battery cell, the battery cells can be connected in series, in parallel or in a mixed connection. A mixed connection means that the battery cells are connected in series and in parallel. The battery cells can be directly connected in series, in parallel or in a mixed connection, and then the whole formed by the battery cells can be accommodated in the housing 5; of course, the battery modules 6 can also be formed by connecting the battery cells in series, in parallel or in a mixed connection, and then the battery modules 6 can be connected in series, in parallel or in a mixed connection to form a whole and accommodated in the housing 5.

[0083] Figure 3 Schematic diagram of an explosion of a battery cell in a battery provided in some embodiments of the present application. In some embodiments, there are multiple battery cells 7, and multiple battery cells 7 are first connected in series, in parallel, or in mixed connection to form a battery module 6. Multiple battery modules 6 are then connected in series, in parallel, or in mixed connection to form a whole, and are accommodated in a box.

[0084] The multiple battery cells 7 in the battery module 6 can be electrically connected through a busbar component to achieve parallel connection, series connection or mixed connection of the multiple battery cells 7 in the battery module 6 .

[0085] The battery cell 7 of the embodiment of the present application comprises an electrode unit 10 , a shell 20 and an end cap assembly 30 . The shell 20 has an opening 21 , the electrode unit 10 is accommodated in the shell 20 , and the end cap assembly 30 is used to connect the shell 20 and cover the opening 21 .

[0086] The electrode unit 10 includes at least one electrode assembly 11. Exemplarily, Figure 3 The electrode unit 10 in the embodiment includes two electrode assemblies 11. The electrode assembly 11 includes a positive electrode sheet, a negative electrode sheet and a separator. The electrode assembly 11 can be a wound electrode assembly, a laminated electrode assembly or other forms of electrode assemblies.

[0087] In some embodiments, the electrode assembly 11 is a wound electrode assembly. The positive electrode sheet, the negative electrode sheet and the separator are all strip-shaped structures. In the embodiment of the present application, the positive electrode sheet, the separator and the negative electrode sheet can be stacked in sequence and wound more than two times to form the electrode assembly 11.

[0088] In other embodiments, the electrode assembly 11 is a laminated electrode assembly. Specifically, the electrode assembly 11 includes a plurality of positive electrode sheets and a plurality of negative electrode sheets, and the positive electrode sheets and the negative electrode sheets are alternately stacked, and the stacking direction is parallel to the thickness direction of the positive electrode sheets and the thickness direction of the negative electrode sheets.

[0089] The electrode unit 10 includes at least one electrode assembly 11. That is, in the battery cell 7, the number of electrode assemblies 11 accommodated in the housing 20 may be one or more.

[0090] The housing 20 is a hollow structure with one side open. The end cap assembly 30 covers the opening 21 of the housing 20 and forms a sealed connection to form a receiving cavity for receiving the electrode unit 10 and the electrolyte.

[0091] The shell 20 can be in various shapes, such as a cylinder, a cuboid, etc. The shape of the shell 20 can be determined according to the specific shape of the electrode unit 10. For example, if the electrode unit 10 is a cylindrical structure, a cylindrical shell can be selected; if the electrode unit 10 is a cuboid structure, a cuboid shell can be selected. Of course, the end cap assembly 30 can also be in various structures, such as a plate-like structure or a hollow structure with one end open. Exemplarily, the shell 20 is a cuboid structure, the end cap assembly 30 is a plate-like structure, and the end cap assembly 30 covers the opening at the top of the shell 20.

[0092] The end cap assembly 30 further includes an electrode terminal 25. In some embodiments, the electrode terminal 25 is provided in two portions, and the two electrode terminals 25 are respectively defined as a positive electrode terminal and a negative electrode terminal. The positive electrode terminal and the negative electrode terminal are respectively used to electrically connect to the positive electrode ear portion and the negative electrode ear portion of the electrode assembly 11 to output the current generated by the electrode assembly 11.

[0093] The end cap assembly 30 further includes a pressure relief mechanism 24, which is used to release the internal pressure or temperature of the battery cell 7 when the internal pressure or temperature of the battery cell 7 reaches a predetermined value. Exemplarily, the pressure relief mechanism 24 is located between the positive electrode terminal and the negative electrode terminal, and the pressure relief mechanism 24 can be a component such as an explosion-proof valve, an explosion-proof disk, a gas valve, a pressure relief valve, or a safety valve.

[0094] In some embodiments, the housing 20 may also be a hollow structure with openings on opposite sides. The end cap assembly 30 includes two end cap assemblies 30, which are respectively covered at the two openings of the housing 20 and sealed to form a receiving cavity for accommodating the electrode unit 10 and the electrolyte. In some examples, the positive electrode terminal and the negative electrode terminal may be mounted on the same end cap assembly 30. In other examples, the positive electrode terminal and the negative electrode terminal are respectively mounted on two end cap assemblies 30.

[0095] The electrode terminal 25 in the end cap assembly is used to lead the current in the electrode assembly 11. Normally, an adapter is provided in the end cap assembly for connecting to the pole ear. Specifically, the pole ear extends from one side of the electrode assembly 11, the pole ear is welded to the adapter, and then the adapter is welded to the electrode terminal to achieve the goal of guiding the current of the electrode assembly 11 to the electrode terminal. However, the inventors found that the above-mentioned structure has low installation efficiency and low yield rate. After analysis, it was found that the welding between the electrode terminal and the adapter is unstable, resulting in a small flow area and high internal resistance in the above structure, causing the temperature of the end cap assembly to be higher and the safety to be reduced. At the same time, the welding operation efficiency is not high, which reduces the production efficiency of the battery cell.

[0096] In view of the above problems, the inventors designed an end cap assembly, which is provided with an electrode lead-out piece, which includes a connecting plate and a pole terminal protruding from the surface of the connecting plate, at least part of the pole terminal is arranged in the first through hole, and the connecting plate is located on one side of the end cap.

[0097] The technical solution of the embodiment of the present application eliminates the original adapter structure, sets an electrode lead-out piece, increases the contact area between the pole and the pole ear, expands the flow area between the pole terminal and the connecting plate, reduces the internal resistance, reduces the temperature rise, and improves the safety performance of the battery cell. In addition, the welding process between the pole terminal and the adapter is eliminated, which improves the efficiency of battery cell production.

[0098] Please continue to refer to Figures 4 to 8 , Figure 4 An exploded schematic diagram of an end cap assembly 30 in a battery 2 provided in some embodiments of the present application; Figure 5 A schematic diagram of the structure of an electrode lead-out member 302 of an end cap assembly 30 provided in some embodiments of the present application; Figure 6 A schematic cross-sectional view of an electrode lead-out member 302 provided in some embodiments of the present application; Figure 7 A schematic cross-sectional view of an end cap assembly 30 provided in some embodiments of the present application; Figure 8 for Figure 7 An enlarged schematic diagram of the circle A in FIG.

[0099] like Figure 4 as well as Figure 5 As shown, the end cap assembly 30 in the embodiment of the present application includes: an end cap 301 and an electrode lead-out member 302. The end cap 301 is provided with a first through hole 303; the electrode lead-out member 302 includes a connecting plate 304 and a pole terminal 305 protruding from the surface of the connecting plate 304, at least part of the pole terminal 305 is provided in the first through hole 303, and the connecting plate 304 is located on one side of the end cap 30.

[0100] The end cap assembly 30 in the embodiment of the present application is covered on the opening 21 of the shell 20 and sealed to form a receiving cavity for accommodating the electrode unit 10 and the electrolyte. Among them, the end cap 301 is a main body 306 structure of the end cap assembly 30, which is in the shape of a flat plate. The edge of the end cap 301 is sealed to the shell 20. The end cap 301 can be made of the same material as the shell 5, and a metal material with a certain strength is usually used to maintain the structure of the receiving cavity and ensure the safety and stability of the electrode assembly 11 during operation.

[0101] In some embodiments, the pole terminal 305 is a solid structure made of a conductive material to ensure the flow area of ​​the pole terminal 305 and the stability of current transmission. The pole terminal 305 can be set as a columnar structure to facilitate connection with an external electrical device or a charging device. The end surface of the pole terminal 305 facing away from the connecting plate 304 is concave to form a recess for connection with other components or connecting structures. The recess can be provided with an internal thread to improve the convenience of connection. The pole terminal 305 can be made of a metal material with a certain strength, such as copper, aluminum alloy, etc. The connecting plate 304 is a flat structure made of a conductive material.

[0102] In some embodiments of the present application, the pole terminal 305 and the connecting plate 304 of the electrode lead-out member 302 are an integrally formed structure, that is, the electrode lead-out member 302 is an integral, indivisible component. In the above structure, the pole terminal 305 and the connecting plate 304 can be made of the same material, cast in the same mold and cooled to form. It is also possible to form a columnar structure on a plate-like structure, and then cut its outer surface to form it. The above manufacturing method is only for the purpose of illustrating the integral molding, and does not limit the manufacturing method of the above electrode lead-out member 302.

[0103] In the technical solution of the embodiment of the present application, the transition piece structure in the end cover assembly 30 is eliminated, and the connecting plate 304 and the pole terminal 305 are set as an integrally formed structure, thereby increasing the contact area between the pole and the pole ear, expanding the current flow area between the pole terminal 305 and the connecting plate 304, reducing the internal resistance, reducing the temperature rise, and improving the safety performance of the battery cell 7.

[0104] In some embodiments of the present application, Figure 6 As shown, the pole terminal 305 includes a body 306 and a first protrusion 307. The body 306 extends along the thickness direction of the end cover 301, the first protrusion 307 protrudes radially from the peripheral side of the body 306, and at least part of the first protrusion 307 is disposed in the first through hole 303.

[0105] In the above technical solution, the outer diameter of the connecting portion between the pole terminal 305 and the first through hole 303 is increased by providing the first protrusion 307 , thereby reducing the movable gap between the pole terminal 305 and the end cover 301 and improving the stability of the pole terminal 305 .

[0106] In some embodiments of the present application, the first protrusion 307 surrounds the main body 306. Through the above technical solution, the first protrusion 307 is set to be annular, which ensures the balance of force between the main body 306 and the end cover in the circumferential direction, and further improves the stability of the pole terminal 305 structure.

[0107] In some embodiments of this application, please refer to Figure 4 , Figure 7 as well as Figure 8 The end cap assembly 30 further includes a seal 308 at least partially arranged around the outer periphery of the first protrusion 307, and at least a portion of the seal 308 is arranged in the first through hole 303. The seal 308 is made of an insulating material, and the seal 308 itself has elasticity and can undergo a certain deformation. The seal 308 can be made of materials such as rubber and silicone. By providing the seal 308, the insulation between the pole terminal 305 and the end cap 301 is achieved.

[0108] In some embodiments of the present application, the end cap assembly 30 further includes: a terminal plate 309 and an insulating member 310. The terminal plate 309 is disposed on a side of the end cap 301 away from the connecting plate 304 and connected to the pole terminal 305; the insulating member 310 is disposed around the pole terminal 305, and at least a portion of the insulating member 310 is disposed between the terminal plate 309 and the end cap 301.

[0109] Specifically, the terminal plate 309 is made of a conductive material, and is used to connect to the pole terminal 305 and lead the current in the pole terminal 305. The electrical equipment or charging device can be directly connected to the terminal plate 309 to achieve current transmission. The insulating member 310 is used to block the current transmission between the terminal plate 309 and the end cover 301, prevent the current from leaking to the end cover 301, and improve the safety performance.

[0110] According to the embodiment of the present application, the pole terminal 305 is fixed by providing a terminal plate 309 , and an insulating member 310 is provided to achieve insulation between the pole terminal 305 and the end cover 301 , thereby preventing power leakage of the battery cell 7 .

[0111] In some embodiments of this application, please refer to Figures 6 to 8A second through hole 311 is provided on the terminal plate 309, and the terminal plate 309 includes an annular first clamping portion 312 protruding from the hole wall of the second through hole 311. The pole terminal 305 also includes an annular second protrusion 313 protruding along the outer peripheral surface of the main body 306, and the second protrusion 313 is spaced apart from the first protrusion 307, wherein the first clamping portion 312 is clamped between the first protrusion 307 and the second protrusion 313.

[0112] In some embodiments, the first clamping portion 312 extends between the first protrusion 307 and the second protrusion 313 , and the end surface shape of the first clamping portion 312 matches the shape of the main body 306 . The first clamping portion 312 can be configured to abut against the main body 306 .

[0113] The above technical solution eliminates the welding connection step between the terminal plate 309 and the pole terminal 305. By providing the first clamping portion 312 and the second protrusion 313, the pole terminal 305 and the terminal plate 309 are clamped and connected, thereby increasing the flow area between the terminal plate 309 and the pole terminal 305 and improving the safety of the battery cell 7.

[0114] In some embodiments of this application, please refer to Figure 8 The insulating member 310 includes a body 314 and a blocking portion 315. At least a portion of the body 314 is disposed between the terminal plate 309 and the end cover 301. The blocking portion 315 protrudes from the side of the body 314 away from the terminal plate 309, extends into the first through hole 303, and is disposed between the end cover 301 and the pole terminal 305. By providing the blocking portion 315 extending into the first through hole 303 and being disposed between the end cover 301 and the pole terminal 305, the insulation performance between the terminal plate 309 and the pole terminal 305 is improved.

[0115] In some embodiments of the present application, the blocking portion 315 extends axially along the first through hole 303 and abuts against the sealing member 308. The above mechanism further enhances the barrier between the end cover 301 and the pole terminal 305, thereby improving the insulation effect.

[0116] In some embodiments of the present application, the seal 308 includes a sealing portion disposed between the pole terminal 305 and the end cover 301 and a connecting portion surrounding the outer periphery of the sealing portion, and at least a portion of the connecting portion is disposed between the end cover 301 and the connecting plate 304. In the above structure, the connecting portion is disposed between the end cover 301 and the connecting plate 304, thereby achieving insulation between the end cover 301 and the connecting plate 304.

[0117] In some embodiments of the present application, Fig. 9As shown, a welding area 316 is provided on the side of the connecting plate 304 away from the end cover 301, and the welding area 316 is used to connect the pole ear of the electrode assembly 11. The welding area 316 can be a planar structure. Optionally, a plurality of welding protrusions can be provided on the welding area 316 to increase the surface area of ​​the welding area 316, increase the area of ​​the connection between the welding area 316 and the pole ear, and improve the firmness of the welding.

[0118] In the above structure, a welding area 316 is provided on the connecting plate 304 to connect the connecting plate 304 with the tab, thereby improving the connection stability.

[0119] In some embodiments of the present application, Fig.10 As shown, the connecting plate 304 includes an extension portion 317 extending outward from one side of the connecting plate 304 along the length direction or width direction of the end cap 301. In some embodiments, at least a portion of the welding area 316 is provided at the extension portion 317. The above structure effectively increases the area of ​​the electrode tab welding by providing the extension portion 317, increases the flow area of ​​the electrode lead-out member 302, and improves the connection efficiency between the electrode tab and the connecting plate 304 and the stability of the structure.

[0120] In some embodiments of the present application, along the length direction of the end cover 301, the distance from the axis of the pole terminal 305 to the geometric center of the connecting plate 304 is greater than 0. By eccentrically arranging the pole terminal 305 on the connecting plate 304, the space of the end cover assembly 300 can be fully utilized to arrange the connecting plate 304, thereby increasing the area of ​​the connecting plate 304 and improving the stability of the connection between the pole ear and the connecting plate 304.

[0121] In some embodiments of the present application, the extension portion 317 extends from one side of the connection plate 304 along the length direction of the end cap 301. In the length direction of the end cap 301, the connection plate 304 includes a first edge and a second edge that are arranged opposite to each other. The first edge is located at the extension portion 317, and the distance from the first edge to the axis of the pole terminal 305 is greater than the distance from the second edge to the axis of the pole terminal 305, so that the connection plate 304 is eccentrically arranged relative to the pole terminal 305. By eccentrically arranging the connection plate 304 relative to the pole terminal 305, the space between the electrode assembly and the end cap 301 can be effectively utilized, the welding area of ​​the pole lug is increased, the stability of the pole lug connection is ensured, the flow area is increased, the internal resistance and temperature rise are reduced, and the stability and safety of the battery cell 7 are improved.

[0122] like Fig.11 As shown, in some embodiments of the present application, a first weight-reducing portion 318 is provided on the extension portion 317, and the thickness of the first weight-reducing portion 318 is less than the thickness of the connecting plate 304. By providing the first weight-reducing portion 318, the weight of the extension portion 317 is effectively reduced, and the energy density of the battery cell 7 is improved.

[0123] In some embodiments of the present application, Fig.10 as well as Fig.11 As shown, the edge of the connecting plate 304 is concave to form a second weight-reducing portion 319. The second weight-reducing portion 319 is effectively provided to reduce the weight of the extending portion 317. In addition, the above technical solution has a simple structure and is easy to implement.

[0124] In some embodiments of the present application, Fig.13 As shown, the edge of the extension portion 317 is concave to form the third weight-reducing portion 320. The above technical solution has a simple structure and is easy to implement.

[0125] In some embodiments of this application, please refer to Fig.12 as well as Fig.13 The minimum distance H2 between the third lightening portion 320 and the pole terminal 305 satisfies H2≥2mm. The third lightening portion 320 is a concave structure, and H2 may be the minimum distance between the edge of the third lightening portion 320 and the outer peripheral surface of the pole terminal 305.

[0126] In the embodiment of the present application, by setting a minimum distance range between the third weight-reducing portion 320 and the pole terminal 305 , the flow area of ​​the connecting plate 304 is ensured while reducing the overall weight of the electrode lead-out member 302 , thereby improving the energy density of the battery cell 7 .

[0127] In some embodiments of the present application, along the width direction of the end cover 301 , the extension length L1 of the connecting plate 304 , the extension length L2 of the third weight reduction portion 320 , and the extension length L3 of the welding area 316 satisfy the relationship: L2≤L1-2(L3+3mm).

[0128] The above technical solution can ensure the welding area of ​​the welding zone 316, improve the stability of the connection between the tab and the electrode lead-out member 302, ensure the flow area, reduce the internal resistance, and reduce the temperature rise. At the same time, the weight of the connecting plate 304 is reduced, achieving the technical effect of reasonable weight reduction and improving the energy density of the battery cell 7.

[0129] In some embodiments of this application, please refer to Figure 4 The end cap assembly 30 further includes an insulating plate 321, a third through hole 322 is provided on the insulating plate 321, at least a portion of the pole terminal 305 is provided in the third through hole 322, the insulating plate 321 is provided on a side of the end cap 301 facing the electrode assembly 11, and at least a portion of the insulating plate 321 is provided between the connecting plate 304 and the end cap 301. By providing the insulating plate 321, insulation between the end cap 301 and the electrode assembly 11 is achieved, thereby improving the safety performance of the battery cell 7.

[0130] Please continue to refer to Figures 14 to 17 , Fig.14 A schematic diagram of the structure of an end cap assembly provided in some embodiments of the present application; Fig.15 for Fig.14 Schematic diagram of the cross-sectional structure of the middle BB section; Fig.16 for Fig.15 An enlarged schematic diagram of the middle circle D; Fig.17 for Fig.15 An enlarged schematic diagram of the middle circle E.

[0131] In some embodiments of the present application, the edges of the insulating plate 321 on opposite sides extend toward the electrode assembly to form a convex portion 323. The convex portions 323 are arranged on both sides of the insulating plate 321, which can define a receiving space between the end cover 301 and the electrode assembly, and at the same time limit the movement of the electrode assembly toward the end cover 301. The above-mentioned receiving space facilitates the arrangement of the connecting plate 304, further ensuring the safety of the battery cell 7.

[0132] In some embodiments of the present application, the maximum distance from the projection of the protrusion 323 on the end cap 301 to the edge of the end cap 301 is C, C ≥ 8.5 mm. The above distance C determines the extension length of the protrusion 323 in the length direction of the end cap 301. Excluding the thickness of the end cap edge of 1.5 mm, the extension length of the protrusion 323 in the length direction of the end cap 301 is greater than or equal to 7 mm. When the extension length of the protrusion 323 is too small, it is possible to cut the electrode assembly and cause damage to the electrode assembly. Therefore, a reasonable setting of the length of the protrusion 323 can ensure the safety performance of the electrode assembly.

[0133] In some embodiments of the present application, the extension length of the connecting plate 304 in the width direction of the end cap 301 is C1, the number of welding areas is two, the two welding areas 316 are arranged along the width direction of the end cap 301, the maximum distance between the two welding areas 316 in the width direction of the end cap 301 is A1, C1 ≥ A1 + 4mm. The above technical solution sets a reasonable length of the non-welding area on the connecting plate 304, reserves sufficient margin for the process of pressing the electrode assembly, ensures the smooth assembly process of the electrode assembly, and improves the safety performance of the battery cell.

[0134] In some embodiments of the present application, in the length direction of the end cap 301, the extension length of the welding area 316 is D1, the extension length of the pole ear is D3, the pole ear is a positive pole ear, and the extension length of the connecting plate is D2D3≥D2≥D1+4mm. The extension length D3 of the pole ear is the maximum extension length of the pole ear in the length direction of the end cap 301.

[0135] In the above structure, the extension length of the pole ear is greater than the length of the connecting plate, which can improve the convenience of the pole ear connection, while reducing the space and weight occupied by the connecting plate, ensuring the energy density of the battery cell. In addition, the length of the connecting plate is greater than the length of the welding area, which reserves sufficient margin during the electrode assembly press-fitting process, ensures the smooth assembly process of the electrode assembly, and improves the safety performance of the battery cell.

[0136] In some embodiments of the present application, in the length direction of the end cap 301, the maximum distance between the orthographic projections of the edges of the two tabs on the end cap is D4, and D1 ≥ (D3-2D4) / 0.8. The length of the above-mentioned welding zone is set by comprehensively considering the maximum misalignment between the tabs and the length of each tab, so as to ensure that each tab of the stacked arrangement can be stably connected to the connecting plate.

[0137] In some embodiments of the present application, an injection hole is further provided on the end cover 301, the distance between the center of the injection hole and the edge of the end cover is D5, the distance between the center of the pole terminal and the edge of the end cover is A2, the pole terminal is a positive pole terminal, and the minimum distance between the center of the pole terminal and the center line of the connecting plate is A3, D5-0.5D2-A2-3mm≥A3≥A+D4+0.5D3-A2.

[0138] The technical solution comprehensively considers the location of the injection hole, the eccentric distance between the pole terminal and the connecting plate, and the maximum misalignment of the two positive pole ears, so as to reasonably set the diameter of the positive pole terminal, reduce the probability of interference between the positive pole terminal and the injection hole, and ensure that the connecting plate does not exceed the edge of the end cover.

[0139] In some embodiments of the present application, the number of electrode lead-out members 302 is two, namely, a first electrode lead-out member and a second electrode lead-out member, a pressure relief mechanism is further provided between the first electrode lead-out member and the second electrode lead-out member, the first electrode lead-out member includes a first connecting plate and a first pole terminal, the second electrode lead-out member includes a second connecting plate and a second pole terminal,

[0140] The length of the end cover is C2, the extension length of the pressure relief mechanism 24 in the length direction of the end cover is C3, the minimum distance from the center line of the first connecting plate to the edge of the end cover is A5 (L5), the minimum distance from the center of the first pole terminal to the center line of the first connecting plate is A6, the extension length of the second pole ear in the length direction of the end cover is L4, and in the length direction of the end cover, the maximum distance between the orthographic projections of the edges of the two second pole ears on the end cover is D6, 0.5 (C2-C3) - A5-0.5L4-3mm ≥ A6 ≥ A + L4 + 0.5D6-A5.

[0141] The above technical solution comprehensively considers the length of the end cover, the extension length of the pressure relief mechanism, the length of the pole ear and the maximum misalignment of multiple second pole ears to set a reasonable diameter of the second pole terminal, reduce the probability of interference between the second pole terminal and the pressure relief mechanism, and at the same time, the second connecting plate does not exceed the edge of the end cover.

[0142] The embodiment of the present application also provides a battery cell 7, including the end cap assembly 30 in the above embodiment. The embodiment of the present application also provides a battery 2, including the battery cell 7 in the above embodiment. The embodiment of the present application also provides an electrical device, the electrical device includes the battery 2 in the above embodiment, and the battery 2 is used to provide electrical energy.

[0143] The technical solution described in the embodiment of the present application is applicable to the battery 2 and the electrical device using the battery 2. The electrical device may be a vehicle 1, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, and the like. The vehicle 1 may be a fuel vehicle, a gas vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, and the like; the spacecraft includes an airplane, a rocket, a space shuttle, and a spacecraft, and the like; the electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and the like; the electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, and the like. The embodiment of the present application does not impose any special restrictions on the above-mentioned electrical devices.

[0144] The end cap assembly 30 in the embodiment of the present application cancels the adapter structure, and sets the connecting plate 304 and the pole terminal 305 as an integrally formed structure, thereby increasing the contact area between the pole and the pole ear, expanding the flow area between the pole terminal 305 and the connecting plate 304, reducing the internal resistance, reducing the temperature rise, and improving the safety performance of the battery cell 7. In addition, the welding process is reduced, and the efficiency of the production of the battery cell 7 is improved. Therefore, the battery cell 7, the battery 2, and the electrical device provided in the embodiment of the present application can also achieve the above-mentioned technical effects due to the provision of the above-mentioned end cap assembly 30, which will not be described in detail here.

[0145] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced with equivalents without departing from the scope of the present application. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. An end cap assembly (30), characterized in that: include: The end cover (301) is provided with a first through hole (303); The electrode lead-out member (302) comprises a connecting plate (304) and a pole terminal (305) protruding from a surface of the connecting plate (304), wherein at least a portion of the pole terminal (305) is disposed in the first through hole (303), and the connecting plate (304) is located on one side of the end cover (301), wherein the connecting plate (304) is used to connect a pole ear of the electrode assembly (11), and the connecting plate (304) comprises a first edge and a second edge disposed opposite to each other along a length direction of the end cover (301), and a first edge and a second edge disposed along a length direction of the end cover (301) are disposed opposite to each other. In the length direction of (301), the distance from the first edge to the edge of the end cover (301) is greater than the distance from the second edge to the edge of the end cover (301), the distance from the first edge to the axis of the pole terminal (305) is greater than the distance from the second edge to the axis of the pole terminal (305), and the connecting plate (304) includes an extension portion (317), the extension portion (317) is located between the first edge and the pole terminal (305), and the extension portion (317) is used to connect the pole lug.

2. The end cap assembly (30) according to claim 1, characterized in that: The connecting plate (304) and the pole terminal (305) are an integrally formed structure; the connecting plate (304) is provided with a welding area (316); and the welding area (316) is used to connect the pole lug.

3. The end cap assembly (30) according to claim 2, characterized in that: The pole terminal (305) comprises a main body (306) extending along the thickness direction of the end cover (301) and a first protrusion (307) protruding from the peripheral side surface of the main body (306) along the radial direction of the main body (306), and at least a part of the first protrusion (307) is arranged in the first through hole (303).

4. The end cap assembly (30) according to claim 3, characterized in that: The first protrusion (307) surrounds the main body (306).

5. The end cap assembly (30) according to claim 3, characterized in that: The end cover assembly (30) further comprises a sealing member (308) which is arranged at least partially around the outer periphery of the first protrusion (307), and at least a portion of the sealing member (308) is arranged in the first through hole (303).

6. The end cap assembly (30) according to claim 5, characterized in that: The end cap assembly (30) further comprises: A terminal plate (309), arranged on a side of the end cover (301) away from the connecting plate (304) and connected to the pole terminal (305); An insulating member (310) is arranged around the pole terminal (305), and at least a portion of the insulating member (310) is arranged between the terminal plate (309) and the end cover (301).

7. The end cap assembly (30) according to claim 6, characterized in that: The terminal plate (309) is provided with a second through hole (311), and the terminal plate (309) comprises an annular first clamping portion (312) protruding from the hole wall of the second through hole (311). The pole terminal (305) further includes a second annular protrusion (313) protruding along the outer peripheral surface of the main body (306), and the second protrusion (313) is arranged at a distance from the first protrusion (307). Wherein, the first clamping portion (312) is clamped between the first convex portion (307) and the second convex portion (313).

8. The end cap assembly (30) according to claim 6 or 7, characterized in that: The insulating member (310) comprises a main body (314) and a blocking portion (315), wherein at least a portion of the main body (314) is disposed between the terminal plate (309) and the end cover (301), and the blocking portion (315) protrudes from a side of the main body (314) away from the terminal plate (309), extends into the first through hole (303), and is disposed between the end cover (301) and the pole terminal (305).

9. The end cap assembly (30) according to claim 8, characterized in that: The blocking portion (315) extends axially along the first through hole (303) and abuts against the sealing member (308).

10. The end cap assembly (30) according to claim 5, characterized in that: The sealing member (308) comprises a sealing portion provided between the pole terminal (305) and the end cover (301) and a connecting portion surrounding the outer periphery of the sealing portion, wherein at least a portion of the connecting portion is provided between the end cover (301) and the connecting plate (304).

11. The end cap assembly (30) according to claim 1, characterized in that: A first weight-reducing portion (318) is provided on the extension portion (317), and the thickness of the first weight-reducing portion (318) is smaller than the thickness of the connecting plate (304).

12. The end cap assembly (30) according to any one of claims 1 to 5, characterized in that: The edge of the connecting plate (304) is concave to form a second weight-reducing portion (319).

13. The end cap assembly (30) according to claim 12, characterized in that: A minimum distance H1 between the second weight-reducing portion (319) and the pole terminal (305) satisfies: H1≥2 mm.

14. The end cap assembly (30) according to claim 2, characterized in that: The edge of the extension portion (317) is concave to form a third weight-reducing portion (320).

15. The end cap assembly (30) according to claim 14, characterized in that: A minimum distance H2 between the third weight-reducing portion (320) and the pole terminal (305) satisfies: H2≥2 mm.

16. The end cap assembly (30) according to claim 15, characterized in that: Along the width direction of the end cover (301), an extension length L1 of the connecting plate (304), an extension length L2 of the third weight-reducing portion (320), and an extension length L3 of the welding area (316) satisfy the relationship: L2≤L1-2(L3+3mm).

17. The end cap assembly (30) according to any one of claims 1 to 5, characterized in that: The end cover assembly (30) further comprises an insulating plate (321), a third through hole (322) being provided on the insulating plate (321), at least a portion of the pole terminal (305) being provided in the third through hole (322), and the insulating plate (321) being provided on a side of the end cover (301) facing the electrode assembly (11), and at least a portion of the insulating plate (321) being provided between the connecting plate (304) and the end cover (301).

18. The end cap assembly (30) according to claim 17, characterized in that: The edges of the insulating plate (321) on opposite sides extend toward the electrode assembly (11) to form convex portions (323).

19. The end cap assembly (30) according to claim 3, characterized in that: The maximum distance between the projection of the convex portion (323) on the end cover (323) and the edge of the end cover (301) is C, and C is ≥ 8.5 mm.

20. The end cap assembly (30) according to claim 2 or 16, characterized in that: In the width direction of the end cover (301), the extension length of the connecting plate (304) is C1, the number of the welding areas (316) is two, the two welding areas (316) are arranged along the width direction of the end cover (301), the maximum distance between the two welding areas (316) in the width direction of the end cover (301) is A1, and C1≥A1+4.

21. The end cap assembly (30) according to claim 2 or 16, characterized in that: In the length direction of the end cover (301), the extension length of the welding area (316) is D1, the extension length of the pole ear is D3, the pole ear is a positive pole ear, the extension length of the connecting plate (304) is D2, and D3≥D2≥D1+4mm.

22. The end cap assembly (30) according to any one of claims 1 to 5, characterized in that: In the length direction of the end cover (301), the maximum distance between the orthographic projections of the edges of the two pole lugs on the end cover (301) is D4, and D1≥(D3-2D4) / 0.

8.

23. The end cap assembly (30) according to any one of claims 1 to 5, characterized in that: The end cover (301) is also provided with a liquid injection hole, the distance between the center of the liquid injection hole and the edge of the end cover (301) is D5, the distance between the center of the pole terminal (305) and the edge of the end cover (301) is A2, the pole terminal is a positive pole terminal, and the minimum distance between the center of the pole terminal (305) and the center line of the connecting plate (304) is A3, D5-0.5D2-A2-3mm≥A3≥C+D4+0.5D3-A2.

24. The end cap assembly (30) according to any one of claims 1 to 5, characterized in that: in, The number of the electrode lead-out pieces (302) is two, namely a first electrode lead-out piece and a second electrode lead-out piece, a pressure relief mechanism is further provided between the first electrode lead-out piece and the second electrode lead-out piece, the first electrode lead-out piece comprises a first connecting plate and a first pole terminal, the second electrode lead-out piece comprises a second connecting plate and a second pole terminal, The length of the end cover is C2, the extension length of the pressure relief mechanism in the length direction of the end cover is C3, the minimum distance from the center line of the first connecting plate to the edge of the end cover is A5, the minimum distance from the center of the first pole terminal to the center line of the first connecting plate is A6, the extension length of the second pole lug in the length direction of the end cover is L4, and the maximum distance between the orthographic projections of the edges of the two second pole lugs on the end cover is D6, 0.5(C2-C3)-A5-0.5L4-3mm≥A6≥C+L4+0.5D6-A5.

25. A battery cell, characterized in that: It comprises an end cap assembly (30) as claimed in any one of claims 1 to 24.

26. A battery, characterized in that: Comprising the battery cell (7) as claimed in claim 25.

27. An electrical device, characterized in that: The electrical device comprises the battery (2) as claimed in claim 26, and the battery (2) is used to provide electrical energy.

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