Battery cell, battery device, and electric device

Abstract

Embodiments of the present application disclose a battery monomer, a battery device and a power utilization equipment. The battery monomer comprises: an electrode assembly comprising a first tab; a shell configured to accommodate the electrode assembly, the shell being provided with a first electrode part; a current collecting member comprising: a first connecting piece configured to be connected with the first electrode part; and a second connecting piece configured to be connected with the first tab; the base metal of the first connecting piece is different from that of the second connecting piece; the first connecting piece and the second connecting piece are welded and form a first welding mark, the shape of the first welding mark is annular with a first opening. The battery monomer, the battery device and the power utilization equipment provided by the embodiments of the present application can improve the structural stability of the battery monomer.

Description

Technical Field

[0001] This application relates to the field of batteries, and more specifically, to a battery cell, a battery device, and an electrical appliance. Background Technology

[0002] Energy conservation and emission reduction are key to the sustainable development of the automotive industry, and electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of this sustainable development. For electric vehicles, battery technology is a crucial factor in their development.

[0003] The processing of a battery cell involves the assembly of multiple components. Improving the quality and efficiency of the processing and assembly of these components to enhance the structural stability of the battery cell has become an urgent problem to be solved. Utility Model Content

[0004] This application provides a battery cell, a battery device, and an electrical appliance, which can improve the structural stability of the battery cell.

[0005] In a first aspect, a battery cell is provided, comprising: an electrode assembly including a first tab; a housing for accommodating the electrode assembly, the housing having a first electrode portion; and a current collector including: a first connector for connecting to the first electrode portion; and a second connector for connecting to the first tab; the base metal of the first connector and the second connector being different; the first connector and the second connector being welded to form a first solder mark, the first solder mark being an annular shape having a first opening.

[0006] Therefore, the base metals of the first connector and the second connector in the current collector of the battery cell in this application embodiment are different. Due to the inherent properties of the metal material, different stress-strain coefficients will cause inconsistent deformation when the first connector and the second connector are welded together. When welding the first connector and the second connector, the first opening can relieve the welding stress, reduce the deformation generated when welding the first connector and the second connector, improve the quality of the current collector, and further improve the connection quality between the current collector and the first tab and the first electrode lead-out part, thereby improving the structural stability of the battery cell.

[0007] In some embodiments, the first weld mark is an annular shape with multiple first openings. By providing multiple first openings, the deformation of the current collector is further reduced during the welding process between the first connector and the second connector, and the stress on the current collector is more uniform, thereby further improving the flatness of the current collector.

[0008] In some embodiments, in a projection plane perpendicular to the thickness direction of the current collector, the sum of the central angles α formed by the geometric centers of the orthographic projection of the first solder mark relative to the orthographic projection of the second connector satisfies: 180°≤α<360°, so as to increase the length of the first solder mark, that is, increase the welding length between the first connector and the second connector, thereby improving the connection strength between the two and improving the stability of the current collector; it can also improve the current carrying capacity of the current collector, thereby improving the performance of the battery cell.

[0009] In some embodiments, the first connector and the second connector are stacked along the thickness direction of the current collector. Considering that the first electrode portion is usually distributed along the thickness direction of the current collector, the stacked first connector and the second connector can facilitate the connection between the upper first connector and the upper first electrode portion, and also facilitate the connection between the lower second connector and the lower first electrode portion, so as to improve processing efficiency.

[0010] In some embodiments, the first connector is annular, and the second connector includes a first portion and a second portion. The first portion is used for welding to the first connector and is disposed around the outer periphery of the second portion. The second portion is provided with a through-hole area and a connection area, and the connection area is used for connecting to the first electrode tab. The through-hole area provides stress relief space for welding stress when welding the second connector and the first electrode tab, reducing the probability of welding deformation in the current collector. Additionally, the through-hole area can also be used to alleviate welding stress when welding the first connector and the second connector, reducing deformation generated during welding.

[0011] In some embodiments, the through-hole area passes through the geometric center of the second connector; and / or, the through-hole area is symmetrically distributed with respect to the geometric center of the second connector, so that the through-hole area is relatively uniformly distributed, thereby making the force distribution of the second part more uniform, reducing the risk of large local deformation of the second connector, and thus improving the stability of the second connector.

[0012] In some embodiments, the through-hole area includes a positioning hole. By including a positioning hole in the through-hole area, the space occupied by the through-hole area can be saved, the size of the connection area can be increased, and thus the connection stability between the second connector and the first tab can be improved.

[0013] In some embodiments, the first connector is provided with a first groove, and in a projection plane perpendicular to the thickness direction of the current collector, the orthographic projection of the first groove at least partially overlaps with the orthographic projection of the first opening. The first groove further alleviates the welding stress between the first connector and the second connector. It can absorb some of the deformation generated during welding, thereby reducing the risk of welding defects in subsequent welding of the current collector, facilitating the implementation of subsequent welding processes, improving the quality of the current collector, and further enhancing the connection quality between the current collector and the first tab and the first electrode portion.

[0014] In some embodiments, the orthographic projection of the first groove lies within the orthographic projection of the first opening. Providing the first solder mark in areas other than the first groove on the first connector can improve the welding strength between the first connector and the second connector, thereby improving the structural stability of the current collector.

[0015] In some embodiments, the first weld mark is an annular shape with a plurality of first openings, and the first connector is provided with a plurality of first grooves, the plurality of first openings and the plurality of first grooves corresponding one to one, so as to improve welding stability and the flatness of the current collection component.

[0016] In some embodiments, the number of the first grooves ranges from [1, 10]. The number of the first grooves should not be excessive to facilitate processing and welding between the first and second connectors.

[0017] In some embodiments, the second connector is provided with a second groove, which is stacked with the first groove along the thickness direction of the current collecting member. On one hand, the second groove can reduce the deformation generated when the second connector is welded to the first electrode lug. On the other hand, the second groove has a similar function to the first groove, which can reduce the welding stress between the first connector and the second connector, thereby reducing the deformation generated when they are welded together.

[0018] In some embodiments, the first electrode portion is welded to the first connector to form a second weld mark; in a projection plane perpendicular to the thickness direction of the current collector, the second weld mark is farther from the geometric center of the orthographic projection of the first connector than the first weld mark. The first weld mark, formed earlier, is closer to the geometric center of the current collector to make the structure of the current collector flatter and reduce deformation. When welding the current collector to the first electrode portion later, considering the limited space of the first connector, especially when the first connector is annular, the second weld mark between the first electrode portion and the first connector is located outside the first weld mark to facilitate welding and improve processing efficiency.

[0019] In some embodiments, the second solder mark is an annular shape with a third opening; in the projection plane perpendicular to the thickness direction of the current collector, the third opening is offset from the first opening, which can make the current collector more uniformly stressed, reduce the risk of excessive stress and large deformation in local areas, and thus improve the structural stability of the current collector.

[0020] In some embodiments, in a projection plane perpendicular to the thickness direction of the current collector, the sum of the central angles β formed by the geometric centers of the orthographic projection of the second weld mark relative to the orthographic projection of the first connector satisfies: 160° ≤ β ≤ 300°. The sum of the central angles β is greater than or equal to 160° to increase the length of the second weld mark, i.e., to increase the welding length between the first electrode and the first connector, thereby improving the connection strength between them and enhancing the stability of the current collector. Furthermore, the sum of the central angles β is less than or equal to 300°, which can limit the size of the third opening, effectively reducing deformation generated during welding of the first connector and the first electrode, alleviating welding stress, further reducing the risk of welding defects in subsequent welding of the current collector, and improving the structural stability of the current collector.

[0021] In some embodiments, the first connector is annular in shape, and / or the second connector is disc-shaped; the first solder mark is annular with the first opening to facilitate processing and welding.

[0022] In some embodiments, the current collector meets at least one of the following conditions: the outer diameter of the first connector is in the range of [20mm, 80mm]; the inner diameter of the first connector is in the range of [10mm, 70mm]; the thickness of the first connector is in the range of [0.1mm, 3mm]; the diameter of the second connector is in the range of [20mm, 80mm]; and the thickness of the second connector is in the range of [0.1mm, 3mm], so that the current collector meets the overcurrent requirements and can also improve the stability of the current collector.

[0023] In some embodiments, the base metal of the first connector is steel or aluminum; the base metal of the second connector is copper, which can better adapt to subsequent welding processes and improve the overall quality of the battery cell.

[0024] In some embodiments, the electrode assembly further includes a second electrode with a polarity opposite to that of the first electrode, the first electrode and the second electrode being located at opposite ends of the electrode assembly, the housing including a shell and an end cap, the shell for accommodating the electrode assembly, the shell being a hollow structure having a fourth opening; the end cap being connected to the shell to cover the fourth opening; the first electrode portion being either the end cap or the shell; the housing further includes a second electrode portion, the second electrode portion being insulated through the bottom wall of the shell and electrically connected to the second electrode, so that the current of the second electrode can be conducted to the outside of the housing through the second electrode portion.

[0025] In a second aspect, a battery device is provided, comprising: a plurality of battery cells, wherein the battery cells are those described in the first aspect or any embodiment of the first aspect.

[0026] Thirdly, an electrical device is provided, comprising: a battery device, the battery device including the battery device described in the first aspect or any embodiment of the first aspect, the battery device being used to supply power to the electrical device.

[0027] In some embodiments, the electrical equipment is a vehicle, a ship, or a spacecraft. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of a vehicle according to one embodiment of this application;

[0029] Figure 2 This is an exploded view of a partial structure of a battery device according to an embodiment of this application;

[0030] Figure 3 This is an exploded view of a partial structure of a battery cell according to an embodiment of this application;

[0031] Figure 4 This is a top view of a current collection component according to an embodiment of this application;

[0032] Figure 5 This is a cross-sectional schematic diagram of a current collection component according to an embodiment of this application;

[0033] Figure 6 This is another top view of a current collection component according to an embodiment of this application;

[0034] Figure 7 This is a top view of a second connector according to an embodiment of this application;

[0035] Figure 8 This is another top view schematic diagram of a current collection component according to an embodiment of this application;

[0036] Figure 9 This is another top view schematic diagram of a current collection component according to an embodiment of this application;

[0037] Figure 10 This is another top view schematic diagram of a current collection component according to an embodiment of this application;

[0038] Figure 11 This is an exploded structural diagram of a current collection component according to an embodiment of this application;

[0039] Figure 12 This is a cross-sectional schematic diagram of a battery cell according to an embodiment of this application;

[0040] Figure 13 This is another top view schematic diagram of a current collection component according to an embodiment of this application.

[0041] The accompanying drawings are not drawn to scale. Detailed Implementation

[0042] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0043] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0044] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0045] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0046] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0047] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0048] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0049] In this application, "multiple" refers to two or more (including two), and similarly, "multiple groups" refers to two or more (including two), and "multiple pieces" refers to two or more (including two).

[0050] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0051] The battery cell can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0052] The battery cells in this application embodiment can be cylindrical battery cells, prismatic battery cells, pouch battery cells, or other shapes of battery cells. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic batteries, such as hexagonal prismatic batteries. This application has no particular limitations.

[0053] In a battery cell, a current collector connects the tab to the corresponding electrode lead to output the battery cell's electrical energy. However, the tab, current collector, and electrode lead may be made of different materials. When welding dissimilar metals, differences in material properties, such as differences in thermal expansion coefficients or melting points, can lead to welding deformation and other problems. For example, the material of the tab may be different from that of the electrode lead. Since the tab needs to be electrically connected to the electrode lead via the current collector, the current collector may include a first connector made of the same material as the tab and a second connector made of the same material as the electrode lead. Because the first and second connectors are made of different materials, welding them together can cause deformation of the first and / or second connectors, affecting the overall flatness of the current collector structure. This affects the welding quality between the current collector and the tab, and between the current collector and the electrode lead, ultimately impacting the performance and structural stability of the battery cell.

[0054] Therefore, embodiments of this application provide a battery cell, a battery device, and an electrical appliance that can solve the above-mentioned problems. Specifically, the battery cell implemented in this application includes an electrode assembly, a housing, and a current collector, wherein the electrode assembly is housed within the housing. The electrode assembly includes a first tab, the housing is provided with a first electrode portion, and the current collector includes a first connector and a second connector. The first connector is used to connect to the first electrode portion, and the second connector is used to connect to the first tab. The base metals of the first connector and the second connector are different, and they are welded together to form a first weld mark, which is formed as an open ring. Because the base metals of the first connector and the second connector are different, due to the inherent properties of the metal materials, different stress-strain coefficients will cause inconsistent deformation when the first connector and the second connector are welded together. When welding the first connector and the second connector, the first opening can alleviate the welding stress, reduce the deformation generated during the welding of the first connector and the second connector, improve the quality of the current collector, and further improve the connection quality between the current collector and the first tab and the first electrode lead-out portion, thereby improving the structural stability of the battery cell.

[0055] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use battery devices.

[0056] Electrical devices can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the above-mentioned electrical devices.

[0057] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device.

[0058] For example, such as Figure 1 The diagram shown is a structural schematic of a vehicle 1 according to one embodiment of this application. Vehicle 1 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A motor 40, a controller 30, and a battery device 10 can be installed inside vehicle 1. The controller 30 controls the battery device 10 to supply power to the motor 40. For example, the battery device 10 can be installed at the bottom, front, or rear of vehicle 1. The battery device 10 can be used to power vehicle 1. For example, the battery device 10 can serve as the operating power source for vehicle 1, for example, to meet the electrical system requirements of vehicle 1, such as for starting, navigation, and operation. In another embodiment of this application, the battery device 10 can not only serve as the operating power source for vehicle 1, but also as the driving power source for vehicle 1, replacing or partially replacing gasoline or natural gas to provide driving power for vehicle 1.

[0059] Figure 2 An exploded view of a portion of the structure of the battery device 10 according to an embodiment of this application is shown. Figure 2 As shown, the battery device 10 of this application embodiment may include a plurality of battery cells 20 to meet different power usage requirements. The shape of the battery cell 20 in this application embodiment can be set according to actual application. For example, the battery cell 20 can be as follows: Figure 2 The cylindrical shape shown, or it could be different. Figure 2 The embodiments shown may be cuboids or other shapes, but are not limited to these.

[0060] It should be understood that, such as Figure 2As shown, the battery device 10 of this embodiment may further include a housing 11, which can be used to accommodate multiple battery cells 20. The housing 11 of this embodiment has a hollow interior, and the multiple battery cells 20 are accommodated within the housing 11. The housing 11 may include two parts, referred to herein as a first housing portion 111 and a second housing portion 112, which are fastened together. The shapes of the first housing portion 111 and the second housing portion 112 can be determined according to the shape of the components housed inside, for example, according to the shape of the combination of the multiple battery cells 20 housed inside. At least one of the first housing portion 111 and the second housing portion 112 has an opening. For example, as... Figure 2 As shown, only one of the first housing portion 111 and the second housing portion 112 may be a hollow cuboid with an opening, while the other may be plate-shaped to cover the opening. Taking the second housing portion 112 as a hollow cuboid with one opening and the first housing portion 111 as a plate-shaped example, the first housing portion 111 covers the opening of the second housing portion 112 to form a housing 11 with a closed chamber, which can be used to accommodate multiple battery cells 20.

[0061] For example, unlike Figure 2 As shown, the first housing portion 111 and the second housing portion 112 can both be hollow cuboids with one open side each. The openings of the first housing portion 111 and the second housing portion 112 are opposite to each other, and the first housing portion 111 and the second housing portion 112 are interlocked to form a housing 11 with a closed chamber, which can be used to accommodate multiple battery cells 20. The multiple battery cells 20 are connected in parallel, series, or mixed and placed inside the housing 11 formed by the interlocking of the first housing portion 111 and the second housing portion 112.

[0062] Figure 3 An exploded view of a partial structure of the battery cell 20 according to an embodiment of this application is shown. For example, the... Figure 3 The battery cell 20 shown can be as follows: Figure 2 The battery device 10 shown includes any one of the battery cells 20. Figure 4 The diagram shows a top view of the current collector 23 included in the battery cell 20 according to an embodiment of this application. For example, the top view is perpendicular to the height direction X of the battery cell 20.

[0063] like Figure 3 and Figure 4As shown, the battery cell 20 of this embodiment includes an electrode assembly 21, a housing 22, and a current collector 23. Specifically, the electrode assembly 21 includes a first tab 211; the housing 22 is used to house the electrode assembly 21, and the housing 22 is provided with a first electrode portion 223; the current collector 23 includes: a first connector 231 for connecting to the first electrode portion 223; and a second connector 232 for connecting to the first tab 211; the base metal of the first connector 231 and the second connector 232 are different; the first connector 231 and the second connector 232 are welded to form a first solder mark 241, and the shape of the first solder mark 241 is an annular shape with a first opening 2411.

[0064] In this embodiment, the electrode assembly 21 is the component in the battery cell 20 where the electrochemical reaction occurs. The electrode assembly 21 is mainly formed by winding or stacking positive and negative electrode sheets, and typically a separator is provided between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets containing active material constitute the main body 213 of the electrode assembly 21, while the portions of the positive and negative electrode sheets without active material each constitute a tab. The positive and negative tabs can be located together at one end of the main body 213 or respectively at both ends of the main body 213. During the charging and discharging process of the battery, the positive and negative active materials react with the electrolyte, and the tabs connect the corresponding electrode portions to form a current loop.

[0065] It should be understood that the electrode assembly 21 in this embodiment includes a first tab 211, which can be any tab of the electrode assembly 21, for example, the first tab 211 can be a positive tab or a negative tab. Correspondingly, the housing 22 is provided with a first electrode portion 223, and the first tab 211 is electrically connected to the first electrode portion 223 through a current collector 23 to output electrical energy. For example, the first tab 211 can be a positive tab, then the first electrode portion 223 is a positive electrode; or, the first tab 211 can also be a negative tab, then the first electrode portion 223 is a negative electrode.

[0066] The housing 22 in this embodiment is a component used to form the internal environment of the battery cell 20. This internal environment can accommodate electrode components 21, electrolyte, and other components. The housing 22 may contain one or more electrode components 21. The housing 22 can have various shapes and sizes, such as cuboid, cylindrical, or hexagonal prism. The shape of the housing 22 can be determined based on the specific shape and size of the electrode components 21. The housing 22 can be made of various materials, such as iron, aluminum, stainless steel, or aluminum alloy.

[0067] For example, the embodiments of this application mainly take the cylindrical battery cell 20 as an example, that is, the outer shell 22 is cylindrical, and the corresponding internal electrode assembly 21 is also cylindrical, but the embodiments of this application are not limited to this.

[0068] The outer casing 22 may include multiple walls, forming a hollow structure to accommodate the electrode assembly 21. In this embodiment, the outer casing 22 is provided with a first electrode portion 223. For example, the first electrode portion 223 may be a conductive component, such as a pole, that passes through any one of the walls of the outer casing 22. Alternatively, in some embodiments, the first electrode portion 223 may also be the outer casing 22 itself, i.e., the first tab 211 is electrically connected to the outer casing 22 via a current collector 23, such that the outer casing 22 serves as the first electrode portion 223 corresponding to the first tab 211. The first electrode portion 223 may be a metal layer made of a single material, a metal layer made of multiple different materials, or a stack of multiple materials with different functions.

[0069] The current collector 23 is a current collector component made of conductive material. When welding and assembling the battery cell 20, the first connector 231 and the second connector 232 of the current collector 23 are usually welded first.

[0070] In this embodiment, the first connector 231 of the current collector 23 is used for conductive connection with the first electrode portion 223 of the housing 22. This connection can be made by welding, specifically laser welding, ultrasonic welding, resistance welding, etc. The second connector 232 of the current collector 23 is used for conductive connection with the first tab 211. This connection can also be made by welding, specifically laser welding, ultrasonic welding, resistance welding, etc. The current collector 23 is connected to the first tab 211 and the first electrode portion 223 via the first connector 231 and the second connector 232, respectively, to output the electrical energy of the battery cell 20.

[0071] In some embodiments, the first connector 231 may be a flat structural member or an irregular shape with flanges. The first connector 231 may be welded to the first electrode portion 223. For example, when the first electrode portion 223 is an end cap 222, the first connector 231 and the end cap 222 may be welded by through welding. As another example, when the first electrode portion 223 is a housing 221, the first electrode portion 223 may also be welded to the inner wall surface of the housing 221, for example, by through welding or butt welding. The embodiments of this application are not limited to these.

[0072] The second connector 232 in this embodiment can be flat, and its specific shape can be set as needed. This embodiment does not limit this.

[0073] In this embodiment, "base metal" refers to the main component metal in a material (e.g., an alloy or composite material), such as a metallic element with a mass fraction greater than 50%. Different base metal materials will have varying properties. The first connector 231 is used for welding to the second connector 232 and the first electrode portion 223, while the second connector 232 is used for welding to the first connector 231 and the first tab 211. Since the welding objects are different, the selection of materials and processing must consider the welding process requirements and other performance requirements when welding to these objects, thereby meeting different connection needs.

[0074] It should be understood that in this application embodiment, the first connector 231 and the second connector 232 are welded to form a first weld mark 241. Specifically, the position of the first weld mark 241 varies depending on the positions of the first connector 231 and the second connector 232. For example, the first connector 231 and the second connector 232 can be stacked, and the stacked first connector 231 and the second connector 232 can be welded together by through welding to form the first weld mark 241. As another example, the first connector 231 and the second connector 232 can also be arranged side by side, and the first connector 231 and the second connector 232 can be welded by butt welding, and the first weld mark 241 is located at the junction of the first connector 231 and the second connector 232. This application embodiment is not limited to this.

[0075] In this embodiment, the first weld mark 241 is annular with a first opening 2411, meaning it is not closed. Because the base metal of the first connector 231 is different from the base metal of the second connector 232, the different stress-strain coefficients due to the inherent properties of the metal materials lead to inconsistent deformation during welding of the first connector 231 and the second connector 232. By setting the shape of the first weld mark 241 to annular with the first opening 2411, welding stress can be alleviated, reducing deformation during welding of the first connector 231 and the second connector 232. This reduces the risk of poor welding in subsequent welding of the current collector 23, facilitating the implementation of subsequent welding processes, improving the quality of the current collector 23, and further enhancing the connection quality between the current collector 23 and the first tab 211 and the first electrode portion 223. Furthermore, by setting the shape of the first weld mark 241 to annular with the first opening 2411, the warpage of the current collector 23 can also be reduced, making it more suitable for assembly requirements. For example, the warpage of the current collector 23 can be reduced to less than or equal to 0.3 mm, so that when selecting the current collector 23, the warpage can be used to quickly determine whether the current collector 23 meets the assembly requirements. Specifically, the lower surface of the second connector 232 of the current collector 23, away from the first connector 231, can be placed on a horizontal plane, and the warpage of the current collector 23 can be obtained by measuring the thickness difference at different positions on the upper surface of the first connector 231 away from the second connector 232.

[0076] In some embodiments, the housing 22 includes a housing 221 and an end cap 222. The housing 221 is used to accommodate the electrode assembly 21 and has a hollow structure with a fourth opening 2211. The end cap 222 is connected to the housing 221 to cover the fourth opening 2211.

[0077] The housing 221 is a component used to cooperate with the end cap 222 to form the internal environment of the battery cell 20. This internal environment can accommodate the electrode assembly 21, electrolyte, and other components. The housing 221 and the end cap 222 can be independent components. A fourth opening 2211 can be provided on the housing 221, and the end cap 222 can close this fourth opening 2211 to form the internal environment of the battery cell 20. Alternatively, the end cap 222 and the housing 221 can be integrated. Specifically, the end cap 222 and the housing 221 can form a common connecting surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing 221, the end cap 222 closes the housing 221. The housing 221 can have various shapes and sizes, such as cuboid, cylindrical, or hexagonal prism. Specifically, the shape of the housing 221 can be determined according to the specific shape and size of the electrode assembly 21. The shell 221 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. This application embodiment does not impose any special restrictions on this.

[0078] End cap 222 refers to a component that covers the opening of housing 221 to isolate the internal environment of battery cell 20 from the external environment. The shape of end cap 222 can be adapted to the shape of housing 221 to fit it. Optionally, end cap 222 can be made of a material with certain hardness and strength (such as aluminum alloy), so that end cap 222 is less prone to deformation under pressure and impact, enabling battery cell 20 to have higher structural strength and improved safety performance. The material of end cap 222 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application embodiment does not impose any special limitations on this.

[0079] The housing 221 in this embodiment may include a side wall 2213 and a bottom wall 2212 located at one end of the side wall 2213. The side wall 2213 may be a wall adjacent to the fourth opening 2211, i.e., the fourth opening 2211 is formed by the side wall 2213 enclosing it. The bottom wall 2212 may be a wall opposite to the fourth opening 2212. Figure 3 and Figure 4 As shown, the side wall 2213 and the bottom wall 2212 can be integrally stamped or formed by welding. The side wall 2213 and the bottom wall 2212 together form a receiving space for accommodating the electrode assembly 21. One end of the receiving space is the bottom wall 2212, and the other end opposite to the bottom wall 2212 is the fourth opening 2211.

[0080] In some embodiments, the first electrode portion 223 is an end cap 222 or a housing 221, that is, the first tab 211 is electrically connected to the housing 221 or the end cap 222 through the current collector 23, so that the housing 221 or the end cap 222 serves as the first electrode portion 223 of the first tab 211. The housing 221 or the end cap 222 serving as the first electrode portion 223 can simplify the structure of the battery cell 20.

[0081] In some embodiments, the electrode assembly 21 further includes a second electrode 212 with the opposite polarity to the first electrode 211. The first electrode 211 and the second electrode 212 are located at opposite ends of the electrode assembly 21. The housing 22 further includes a second electrode portion 224, which is insulated through the bottom wall 2212 of the housing 221 and electrically connected to the second electrode 212. Specifically, the first electrode 211 and the second electrode 212 have opposite polarities and are arranged opposite to each other for ease of processing. The second electrode portion 224 may be an electrode post. The bottom wall 2212 has an electrode lead-out hole. The second electrode portion 224 is insulatedly connected to the electrode lead-out hole on the bottom wall 2212 through an insulating member. The portion of the second electrode portion 224 located within the receiving space is electrically connected to the second electrode 212, so that the current of the second electrode 212 can be conducted to the outside of the housing 22 through the second electrode portion 224.

[0082] For example, the first electrode 211 can be a positive electrode, and the corresponding second electrode 212 can be a negative electrode, in which case the first electrode portion 223 is a positive electrode and the second electrode portion 224 is a negative electrode; or, the first electrode 211 can also be a negative electrode, and the corresponding second electrode 212 can be a positive electrode, in which case the first electrode portion 223 is a negative electrode and the second electrode portion 224 is a positive electrode.

[0083] It should be understood that the material of the current collector 23 in this application embodiment can be set according to actual application. For example, the material of the first connector 231 and the material of the first electrode 223 can be set to be the same so that the first connector 231 and the first electrode 223 can be fused smoothly to meet the overcurrent requirements and strength requirements; the material of the second connector 232 and the material of the first tab 211 can be set to be the same so that the welding of the current collector 23 and the electrode assembly 21 can also meet the overcurrent requirements.

[0084] In some embodiments, the base metal of the first connector 231 is steel or aluminum; and / or the base metal of the second connector 232 is copper, which can better adapt to subsequent welding processes and improve the overall quality of the battery cell 20.

[0085] The structure of the current collection component 23 in the embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0086] Figure 5 A cross-sectional schematic diagram of the current collection member 23 according to an embodiment of this application is shown, for example, Figure 5 It can be Figure 4 The diagram shows a cross-sectional view of the current collection member 23, and this cross-section is along the... Figure 5 The cross-sectional view along the A-A' direction is shown.

[0087] It should be understood that the positional relationship between the first connector 231 and the second connector 232 in the embodiments of this application can be set according to actual applications.

[0088] In some embodiments, the first connector 231 and the second connector 232 are stacked along the thickness direction of the current collecting member 23. For example, as Figures 3 to 5 As shown in the embodiment of this application, taking the thickness direction of the current collector 23 as the height direction X of the battery cell 20 as an example, the first connector 231 and the second connector 232 can be stacked along the height direction X of the battery cell 20. Considering that the first electrode portion 223 is usually distributed along the thickness direction of the current collector 23 with the first tab 211, the stacked first connector 231 and second connector 232 can facilitate the connection between the upper first connector 231 and the upper first electrode portion 223, and also facilitate the connection between the lower second connector 232 and the lower first tab 211, thereby improving processing efficiency.

[0089] It should be understood that when the first connector 231 and the second connector 232 are stacked along the thickness direction of the current collecting member 23, the first connector 231 and the second connector 232 can be welded by penetration welding to form a first weld mark 241. For example, as Figure 5 As shown, taking penetration welding from the surface of the first connector 231 away from the second connector 232 as an example, the first weld mark 241 penetrates at least the first connector 231 and at least partially penetrates the second connector 232 to improve welding stability, but the embodiments of this application are not limited to this.

[0090] In some embodiments, with Figures 3 to 5 Different from the illustrated embodiment, the first connector 231 and the second connector 232 can also have other positional relationships, for example, they can be arranged side by side. For example, in a direction perpendicular to the thickness direction of the flow collecting member 23, the first connector 231 and the second connector 232 can be arranged side by side. As another example, the first connector 231 can be annular, and is arranged around the outer periphery of the second connector 232.

[0091] When the first connector 231 and the second connector 232 are arranged side by side, they can form a first weld mark 241 by butt welding. The embodiments of this application are not limited to this.

[0092] For ease of description, the embodiments of this application are mainly described using the example of the first connector 231 and the second connector 232 being stacked along the thickness direction of the flow collector 23.

[0093] It should be understood that the shapes of the first connector 231 and the second connector 232 in this application embodiment can be set according to actual applications. For example, the shapes of the first connector 231 and the second connector 232 can be the same or different to suit different application scenarios. As another example, the first connector 231 can be annular, that is, the central area of ​​the first connector 231 has a hollow structure to save the weight and space occupied by the first connector 231. For example, the first connector 231 can be a circular ring or a square ring for ease of processing.

[0094] In some embodiments, such as Figures 3 to 5 As shown, taking a cylindrical battery cell 20 as an example, the first connector 231 is annular in shape, and / or the second connector 232 is disc-shaped to facilitate processing and welding. Specifically, the first connector 231 is annular, meaning its central area is hollow. The second connector 232 is disc-shaped, meaning it is a cylindrical shape with a relatively small height.

[0095] Furthermore, the first solder mark 241 is an annular ring with a first opening 2411. For example, the shape of the first solder mark 241 is similar to the shape of the first connector 231, so as to facilitate the welding between the first connector 231 and the second connector 232.

[0096] In some embodiments, the dimensions of the first connector 231 and the second connector 232 can be set according to the actual application. For example, Figures 3 to 5 As shown, the current collector 23 satisfies at least one of the following conditions: the outer diameter R2 of the first connector 231 ranges from [20mm to 80mm]; the inner diameter R1 of the first connector 231 ranges from [10mm to 70mm]; the thickness T1 of the first connector 231 ranges from [0.1mm to 3mm]; the diameter D of the second connector 232 ranges from [20mm to 80mm]; and the thickness T2 of the second connector 232 ranges from [0.1mm to 3mm], so that the current collector 23 can meet the flow requirements and improve the stability of the current collector 23. Here, "mm" represents the unit of length, millimeter.

[0097] In some embodiments, the outer diameter R2 of the first connector 231 may be any of the following values, or be between any two of the following values: 20mm, 25mm, 30mm, 35mm, 40mm, 45mm, 50mm, 55mm, 60mm, 65mm, 70mm, 75mm or 80mm.

[0098] In some embodiments, the inner diameter R1 of the first connector 231 may be any of the following values, or be between any two of the following values: 10mm, 15mm, 20mm, 25mm, 30mm, 35mm, 40mm, 45mm, 50mm, 55mm, 60mm, 65mm or 70mm.

[0099] In some embodiments, the thickness T1 of the first connector 231 can be any of the following values, or be between any two of the following values: 0.1mm, 0.3mm, 0.5mm, 0.8mm, 1mm, 1.3mm, 1.5mm, 1.8mm, 2mm, 2.3mm, 2.5mm, 2.8mm or 3mm.

[0100] In some embodiments, the diameter D of the second connector 232 may be any of the following values, or be between any two of the following values: 20mm, 25mm, 30mm, 35mm, 40mm, 45mm, 50mm, 55mm, 60mm, 65mm, 70mm, 75mm or 80mm.

[0101] In some embodiments, the thickness T2 of the second connector 232 may be any of the following values, or be between any two of the following values: 0.1mm, 0.3mm, 0.5mm, 0.8mm, 1mm, 1.3mm, 1.5mm, 1.8mm, 2mm, 2.3mm, 2.5mm, 2.8mm or 3mm.

[0102] It should be understood that the first solder mark 241 in this embodiment is annular in shape with a first opening 2411, wherein the number of the first openings 2411 can be set according to the actual application. For example, as Figure 4 and Figure 5 As shown, the first weld mark 241 can be an annular shape with a first opening 2411 to improve the welding efficiency between the first connector 231 and the second connector 232. The position of the first opening 2411 can be set according to welding requirements to improve processing flexibility.

[0103] Figure 6 Another top view of the current collector 23 according to an embodiment of this application is shown. For example, this top view is perpendicular to the height direction X of the battery cell 20, and... Figure 6 The first solder mark 241 of the current collector 23 shown is different from the first solder mark 241 shown. Figure 5 The first solder mark 241 of the current collector 23 shown is... Figure 6 The first solder mark 241 shown is another possible implementation of the embodiments of this application.

[0104] In some embodiments, the first solder mark 241 is annular in shape with a plurality of first openings 2411, such that the first solder mark 241 comprises multiple discontinuous solder marks. For example, as Figure 6 As shown, the first solder mark 241 is a ring with three first openings 2411, and the first solder mark 241 includes three arc segments that are discontinuous.

[0105] By setting multiple first openings 2411, the deformation of the current collecting member 23 is further reduced during the welding process of the first connector 231 and the second connector 232, and the current collecting member 23 is subjected to more uniform force, thereby further improving the flatness of the current collecting member 23.

[0106] It should be understood that when the shape of the first weld mark 241 is an annular ring with multiple first openings 2411, the position and size of the multiple first openings 2411 can be set according to the actual application. For example, the lengths of the multiple first openings 2411 along the circumference of the ring can be the same; or, for another example, the multiple first openings 2411 can be symmetrically distributed along the circumference of the ring. This makes the multiple weld marks included in the first weld mark 241 uniformly distributed, reducing the possibility of excessive or insufficient local deformation, and improving the structural stability of the current collection member 23.

[0107] It should be understood that the dimensions of the first solder mark 241 in this embodiment can be set according to actual application. In some embodiments, in a projection plane perpendicular to the thickness direction of the current collector 23, the sum of the central angles α formed by the geometric center O of the orthographic projection of the first solder mark 241 relative to the orthographic projection of the second connector 232 satisfies: 180° ≤ α < 360°. The plane perpendicular to the thickness direction of the current collector 23 in this embodiment is, for example, a plane parallel to the surface of the second connector 232 facing the first connector 231, or it can be the surface of the second connector 232 facing the first connector 231.

[0108] In some embodiments, if the shape of the first solder mark 241 is an annular ring with a first opening 2411, then the sum of the central angles α in this embodiment is the central angle of the orthographic projection of the first solder mark 241. Figure 6 As shown, if the shape of the first solder mark 241 is an annular ring with multiple first openings 2411, then the first solder mark 241 includes multiple solder segments. For example, taking a three-segment solder mark as an example, and the central angles formed by the orthographic projections of the three solder segments relative to the geometric center O of the orthographic projection of the second connector 232 are α1, α2, and α3, respectively, then, in the projection plane perpendicular to the thickness direction of the current collecting member 23, the sum of the central angles formed by the orthographic projections of the first solder mark 241 relative to the geometric center O of the orthographic projection of the second connector 232 is α = α1 + α2 + α3. The values ​​of α1, α2, and α3 can be the same or different.

[0109] In some embodiments, in a projection plane perpendicular to the thickness direction of the current collector 23, the sum of the central angles α formed by the geometric center O of the orthographic projection of the first solder mark 241 relative to the orthographic projection of the second connector 232 is generally greater than or equal to 180°, so as to increase the length of the first solder mark 241, that is, to increase the welding length between the first connector 231 and the second connector 232, thereby improving the connection strength between the two and improving the stability of the current collector 23; it can also improve the current carrying capacity of the current collector 23, thereby improving the performance of the battery cell 20.

[0110] In some embodiments, in a projection plane perpendicular to the thickness direction of the current collector 23, the sum of the central angles α formed by the geometric center O of the orthographic projection of the first weld mark 241 relative to the orthographic projection of the second connector 232 typically satisfies: 200° ≤ α ≤ 280°. Setting this sum of central angles α to be greater than or equal to 200° further increases the welding length between the first connector 231 and the second connector 232, thereby improving the stability and flow capacity of the current collector 23. Furthermore, setting this sum of central angles α to be less than or equal to 280° limits the size of the first opening 2411, effectively reducing deformation during welding of the first connector 231 and the second connector 232, alleviating welding stress, and further reducing the risk of welding defects in subsequent welding of the current collector 23.

[0111] In some embodiments, in the projection plane perpendicular to the thickness direction of the current collector 23, the sum of the central angles α formed by the geometric center O of the orthographic projection of the first solder mark 241 relative to the orthographic projection of the second connector 232 can be any of the following values, or be between any two of the following values: 180°, 190°, 200°, 210°, 220°, 230°, 240°, 250°, 260°, 270°, 280°, 290°, 300°, 310°, 320°, 330°, 340°, 350°.

[0112] Figure 7 A top view of the second connector 232 according to an embodiment of this application is shown. For example, the... Figure 7 The second connector 232 shown can be as follows: Figures 3 to 6 One possible implementation of the second connector 232 included in the flow collector 23 shown is exemplified by the second connector 232 being disc-shaped, but the embodiments of this application are not limited thereto.

[0113] In this embodiment of the application, taking the first connector 231 as an annular shape as an example, the second connector 232 includes a first part 2321 and a second part 2322. The first part 2321 is used to weld to the first connector 231. The first part 2321 is arranged around the outer periphery of the second part 2322. The second part 2322 is provided with a through hole area 2323 and a connecting area 2324. The connecting area 2324 is used to connect to the first electrode tab 211.

[0114] like Figure 7As shown, when the first connector 231 is annular, the first connector 231 and the first portion 2321 of the second connector 232 are stacked along the thickness direction of the current collecting member 23. That is, in the projection plane perpendicular to the thickness direction of the current collecting member 23, the orthographic projection of the first connector 231 coincides with the orthographic projection of the first portion 2321 of the second connector 232. The first connector 231 and the first portion 2321 are welded together to form a first weld mark 241, thereby realizing the mutual connection and fixation between the first connector 231 and the second connector 232.

[0115] like Figure 7 As shown, the second connector 232 also includes a second part 2322, and the first part 2321 is disposed around the outer periphery of the second part 2322. Specifically, the first connector 231 is annular, with a hollow area in the middle, and the second part 2322 of the second connector 232 is disposed corresponding to the hollow area, that is, the second part 2322 is the area of ​​the second connector 232 other than the first part 2321.

[0116] The second part 2322 is provided with a connection area 2324, which is used to connect with the first electrode tab 211, for example, it can be used for welding to the first electrode tab 211. The second part 2322 is also provided with a through hole area 2323, which includes one or more through holes extending through the second part 2322 along the thickness direction of the second connector 232. The through hole area 2323 can provide stress relief space for welding stress when welding the second connector 232 and the first electrode tab 211, reducing the probability of welding deformation of the current collector 23; in addition, the through hole area 2323 can also be used to relieve welding stress when welding the first connector 231 and the second connector 232, reducing the deformation generated when welding the first connector and the second connector.

[0117] It should be understood that the number and shape of the through holes included in the through-hole area 2323 of the second part 2322 can be set according to the actual application. For example, the through-hole area 2323 can be set according to the position of the connection area 2324 to reduce the impact of the through-hole area 2323 on the connection area 2324, thereby improving the connection reliability between the connection area 2324 and the first electrode 211. For example, as Figure 7 As shown, the through hole region 2323 includes through holes that can be elongated to divide the second part 2322 into multiple regions. The connection region 2324 includes these multiple regions, and each region can be used to connect to the first tab 211.

[0118] In some embodiments, the through-hole area 2323 passes through the geometric center of the second connector 232, and / or the through-hole area 2323 is symmetrically distributed with respect to the geometric center of the second connector 232, so that the through-hole area 2323 is relatively uniformly distributed, thereby making the force distribution of the second part 2322 more uniform, reducing the risk of large local deformation of the second connector 232, and thus improving the stability of the second connector 232.

[0119] In some embodiments, the through-hole region 2323 may include various types of through holes provided on the second part 2322. For example, the through-hole region 2323 includes a positioning hole 2325, which can be used for positioning when the current collector 23 is connected to the first tab 211 and to the first electrode part 223, thereby reducing the risk of misalignment of the current collector 23. By providing the through-hole region 2323 with the positioning hole 2325, the space occupied by the through-hole region 2323 can be saved, the size of the connection region 2324 can be increased, and the connection stability between the second connector 232 and the first tab 211 can be improved.

[0120] Figure 8 This illustration shows another top view of the current collector 23 according to an embodiment of this application. For example, this top view is perpendicular to the height direction X of the battery cell 20, and... Figure 8 The flow collector 23 shown is different from the flow collector 23 shown. Figure 5 and Figure 6 The flow collector component 23 shown is shown. Figure 8 The flow collector 23 shown is another possible implementation of the embodiment of this application.

[0121] In some embodiments, such as Figure 8 As shown, when the second connector 232 is provided with a through hole area 2323, the second connector 232 is welded to the first connector 231 to form a first weld mark 241. The shape of the first weld mark 241 can be annular, and the annular shape does not have an opening.

[0122] Figure 9 This illustration shows another top view of the current collector 23 according to an embodiment of this application. For example, this top view is perpendicular to the height direction X of the battery cell 20, and... Figure 9 The flow collector 23 shown is different from the flow collector 23 shown. Figure 8 The flow collector component 23 shown is shown. Figure 9 The flow collector 23 shown is another possible implementation of the embodiment of this application.

[0123] In some embodiments, such as Figure 9As shown, when the second connector 232 is provided with a through hole area 2323, the second connector 232 is welded to the first connector 231 to form a first solder mark 241. The shape of the first solder mark 241 can be an annular shape with a first opening 2411. For example, the annular shape can have one or more first openings 2411, and the embodiments of this application are not limited thereto.

[0124] In some embodiments, such as Figure 9 As shown, when the first solder mark 241 is annular with a first opening 2411, the position of the through hole included in the through hole area 2323 of the second part 2322 can correspond to the first solder mark 241; or it can be different. Figure 9 The through holes included in the through hole area 2323 may also correspond to the position of the first opening 2411, but the embodiments of this application are not limited thereto.

[0125] Figure 10 This illustration shows another top view of the current collector 23 according to an embodiment of this application. For example, this top view is perpendicular to the height direction X of the battery cell 20, and... Figure 10 The flow collector 23 shown is different from the flow collector 23 shown. Figure 5-6 and Figure 8-9 The flow collector component 23 shown is shown. Figure 10 The flow collector 23 shown is another possible implementation of the embodiment of this application. Figure 11 An exploded structural diagram of the current collection component 23 according to an embodiment of this application is shown, for example, Figure 11 It can be Figure 10 The exploded structural diagram of the current collection component 23 is shown.

[0126] In some embodiments, the first connector 231 is provided with a first groove 2311, and in a projection plane perpendicular to the thickness direction of the current collector 23, the orthographic projection of the first groove 2311 at least partially overlaps with the orthographic projection of the first opening 2411. The first groove 2311 alleviates the welding stress between the first connector 231 and the second connector 232. It also absorbs some of the deformation generated during welding, thereby reducing the risk of poor welding in subsequent welding of the current collector 23 and facilitating the implementation of subsequent welding processes. This improves the quality of the current collector 23 and further enhances the connection quality between the current collector 23 and the first tab 211 and the first electrode portion 223.

[0127] In some embodiments, the orthographic projection of the first groove 2311 lies within the orthographic projection of the first opening 2411. For example... Figure 10 and Figure 11As shown, in the projection plane perpendicular to the thickness direction of the current collecting member 23, the orthographic projection of the first groove 2311 is located within the orthographic projection of the first opening 2411, which means that in the projection plane perpendicular to the thickness direction of the current collecting member 23, along the circumference of the current collecting member 23, the orthographic projection of the first opening 2411 can cover the orthographic projection of the first groove 2311, that is, the length of the first opening 2411 along its ring is greater than the length of the first groove 2311 along its ring, or in other words, the first solder mark 241 is not located in the area where the first groove 2311 is located.

[0128] Setting the first weld mark 241 in areas other than the first groove 2311 of the first connector 231 can improve the welding strength between the first connector 231 and the second connector 232, thereby improving the structural stability of the current collector 23.

[0129] It should be understood that the specific structure of the first groove 2311 in this application embodiment can be configured according to actual application. In some embodiments, the first groove 2311 can be a recessed structure with an opening, wherein the opening of the first groove 2311 can face any direction. For example, the opening of the first groove 2311 can face the geometric center of the first connector 231; or it can be away from the geometric center of the first connector 231; or it can be facing the second connector 232; or it can be away from the second connector 232. This application embodiment is not limited to this.

[0130] In some embodiments, the first groove 2311 may also be a partially thinned structure of the first connector 231, such that the thickness of the first groove 2311 along the thickness direction of the collector 23 is less than the thickness of other areas of the first connector 231, and / or, the width of the first groove 2311 along the radial direction of the collector 23 is less than the width of other areas of the first connector 231.

[0131] In some embodiments, the first groove 2311 may also be a non-connected area on the first connector 231. Specifically, as Figure 10 and Figure 11 As shown, the first connector 231 is an annular shape with a second opening, meaning that the first connector 231 is not closed and may include a multi-segment structure. The first groove 2311 is the second opening, which helps to reduce the welding stress between the first connector 231 and the second connector 232 through the second opening, thereby reducing the deformation generated during welding and improving the welding quality.

[0132] It should be understood that the number of first grooves 2311 in the embodiments of this application can be set according to actual applications. For example, the number of first openings 2411 can be related to the number of first grooves 2311. The number of first openings 2411 can be greater than or equal to the number of first grooves 2311.

[0133] In some embodiments, the first solder mark 241 is annular in shape with a plurality of first openings 2411, and the first connector 231 is provided with a plurality of first grooves 2311, with the plurality of first openings 2411 and the plurality of first grooves 2311 corresponding one-to-one. For example, as Figure 10 and Figure 11 As shown, taking the first groove 2311 as the second opening as an example, the shape of the first weld mark 241 is an annulus with four first openings 2411, and the shape of the first connector 231 is also an annulus with four second openings, so that the four weld marks included in the first weld mark 241 are respectively located in the four sections of the first connector 231, so as to improve the welding stability and the flatness of the current collection component 23.

[0134] In some embodiments, the second connector 232 is provided with a second groove 23211, which is stacked with the first groove 2311 along the thickness direction of the current collector 23. On one hand, the second groove 23211 functions similarly to the through-hole region 2323, reducing deformation during welding of the second connector 232 and the first tab 211. On the other hand, the second groove 23211 functions similarly to the first groove 2311, reducing welding stress between the first connector 231 and the second connector 232, thereby reducing deformation during welding. In other words, the second groove 23211 improves the structural stability of the current collector 23, reduces its weight, and increases the energy density of the battery cell 20.

[0135] It should be understood that, similar to the first groove 2311, the specific structure of the second groove 23211 in this application embodiment can be set according to actual application. For example, the second groove 23211 can be a recessed structure with an opening, wherein the opening of the second groove 23211 can face any direction, and the opening orientation of the second groove 23211 can be the same as or different from the opening orientation of the first groove 2311. This application embodiment is not limited to this.

[0136] In some embodiments, the second groove 23211 may also be a partially thinned region of the second connector 232, such that the thickness of the second groove 23211 along the thickness direction of the collector 23 is less than the thickness of other regions of the first part 2321, and / or the width of the second groove 23211 along the radial direction of the collector 23 is less than the width of other regions of the first part 2321.

[0137] In some embodiments, the second groove 23211 may also be a non-connected area on the first step 2321. Specifically, as Figure 10 and Figure 11 As shown, the second groove 23211 can penetrate the first part 2321 so that the edge of the first part 2321 has an opening, and the second groove 23211 includes the opening.

[0138] It should be understood that the number of second grooves 23211 in this application embodiment can be set according to actual application. For example, the number of second grooves 23211 can be less than or equal to the number of first grooves 2311 in the first connector 231, and this application embodiment is not limited thereto.

[0139] In some embodiments, the number of first grooves 2311 ranges from [1, 10]. Limiting the number of first grooves 2311 to a minimum facilitates processing and welding between the first connector 231 and the second connector 232. Correspondingly, the number of first openings 241 should also not be excessive to facilitate welding. Furthermore, the number of first grooves 2311 can be set to a range of [1, 5] to improve processing efficiency.

[0140] Figure 12 A cross-sectional schematic diagram of the battery cell 20 according to an embodiment of this application is shown. For example, the... Figure 12 It can be like Figure 3 The diagram shows a cross-sectional view of the battery cell 20, which passes through the central axis of the cylindrical battery cell 20. Figure 13 This illustration shows another top view of the current collector 23 according to an embodiment of this application. For example, this top view is perpendicular to the height direction X of the battery cell 20. Figure 13 The flow collector 23 shown can be as follows Figure 6 Another top view of the flow collector 23 shown.

[0141] In some embodiments, the first electrode portion 223 is welded to the first connector 231 to form a second solder mark 242; in a projection plane perpendicular to the thickness direction of the current collector 23, the second solder mark 242 is farther from the geometric center O of the orthographic projection of the first connector 231 than the first solder mark 241. Figure 12 and Figure 13As shown, in the projection plane perpendicular to the thickness direction of the current collector 23, the geometric center O of the orthographic projection of the second solder mark 242 relative to the first solder mark 241 away from the first connector 231 means that in the projection plane perpendicular to the thickness direction of the current collector 23, in the radial direction along the current collector 23, that is, in the direction extending from the geometric center O of the orthographic projection of the first connector 231 to the edge of the first connector 231, the second solder mark 242 is located on the outside and the first solder mark 241 is located on the inside.

[0142] Considering the processing sequence of the battery cell 20, the first connector 231 and the second connector 232 of the current collector 23 are welded first to form a first weld mark 241. The closer the first weld mark 241 is to the geometric center O of the current collector 23, the less deformation will occur during the welding of the first connector 231 and the second connector 232. Therefore, the first weld mark 241 formed first can be closer to the geometric center O of the current collector 23, so that the structure of the current collector 23 is flatter and deformation is reduced.

[0143] When welding the current collector 23 to the first electrode 223, considering the limited space of the first connector 231, especially when the first connector 231 is annular with a hollow central area and a first weld mark 241 already formed near the central area, the second weld mark 242 between the first electrode 223 and the first connector 231 can be located outside the first weld mark 241 to facilitate welding, improve processing efficiency, and increase the circumference of the second weld mark 242 to improve the welding stability between the first electrode 223 and the first connector 231 and improve the current carrying capacity of the current collector 23.

[0144] In some embodiments, the second solder mark 242 is annular in shape with a third opening 2421; in a projection plane perpendicular to the thickness direction of the current collector 23, the third opening 2421 is offset from the first opening 2411. Figure 12 and Figure 13 As shown, the second solder mark 242 is an annular shape with a third opening 2421, that is, the second solder mark 242 is not closed, so as to reduce the deformation generated during welding and improve the welding quality between the first electrode part 223 and the first connector 231.

[0145] In the projection plane perpendicular to the thickness direction of the current collector 23, the misalignment of the third opening 2421 and the first opening 2411 means that, in the projection plane perpendicular to the thickness direction of the current collector 23, along the radial direction of the current collector 23 (i.e., along the direction extending from the geometric center O of the current collector 23 to its edge), the first opening 2411 corresponds to the position of the second solder mark 242, while the third opening 2421 corresponds to the position of the first solder mark 241. In other words, along the radial direction of the current collector 23, the first opening 2411 and the third opening 2421 are misaligned. This misalignment of the first opening 2411 and the third opening 2421 allows for more uniform stress distribution on the current collector 23, reducing the risk of excessive stress and deformation in localized areas, thereby improving the structural stability of the current collector 23.

[0146] It should be understood that the size of the second solder mark 242 in this application embodiment can be set according to the actual application.

[0147] In some embodiments, in a projection plane perpendicular to the thickness direction of the current collector 23, the sum of the central angles β formed by the geometric centers of the orthographic projection of the second solder mark 242 relative to the orthographic projection of the first connector 231 satisfies: 160° ≤ β ≤ 300°. For example, if the shape of the second solder mark 242 is an annular ring with a third opening 2421, then in this embodiment, the sum of the central angles β is the central angle of the orthographic projection of the second solder mark 242. Figure 13 As shown, if the shape of the second solder mark 242 is an annular ring with multiple third openings 2421, then the second solder mark 242 includes multiple solder segments. For example, taking a three-segment solder mark as an example, and the central angles formed by the orthographic projections of the three solder segments relative to the geometric center O of the orthographic projection of the first connector 231 are β1, β2, and β3, respectively, then, in the projection plane perpendicular to the thickness direction of the current collector 23, the sum of the central angles formed by the orthographic projections of the second solder mark 242 relative to the geometric center O of the orthographic projection of the first connector 231 is β = β1 + β2 + β3. The values ​​of β1, β2, and β3 can be the same or different.

[0148] In the projection plane perpendicular to the thickness direction of the current collector 23, the sum of the central angles β formed by the geometric centers of the orthographic projection of the second weld mark 242 relative to the orthographic projection of the first connector 231 is usually greater than or equal to 160°, so as to increase the length of the second weld mark 242, that is, to increase the welding length between the first electrode portion 223 and the first connector 231, thereby improving the connection strength between the two and improving the stability of the current collector 23; in addition, the sum of the central angles β is usually less than or equal to 300°, so as to limit the size of the third opening 2421, effectively reduce the deformation generated when the first connector 231 and the first electrode portion 223 are welded, relieve welding stress, further reduce the risk of welding defects in subsequent welding of the current collector 23, and improve the structural stability of the current collector 23.

[0149] In some embodiments, in the projection plane perpendicular to the thickness direction of the current collector 23, the sum of the central angles β formed by the geometric centers of the orthographic projection of the second solder mark 242 relative to the orthographic projection of the first connector 231 can be any of the following values, or be between any two of the following values: 160°, 180°, 200°, 210°, 220°, 230°, 240°, 250°, 260°, 270°, 280°, 290°, or 300°.

[0150] According to some embodiments of this application, this application also provides a battery device 10, including a battery cell 20 as described in any of the above embodiments.

[0151] According to some embodiments of this application, this application also provides an electrical device including the battery device 10 described in any of the above embodiments, and the battery device 10 is used to provide electrical energy to the electrical device.

[0152] The electrical equipment can be any of the aforementioned devices or systems that use batteries.

[0153] According to some embodiments of this application, see Figures 3 to 13 This application provides a battery cell 20, including: an electrode assembly 21, including a first tab 211; a housing 22 for accommodating the electrode assembly 21, the housing 22 being provided with a first electrode portion 223; and a current collector 23, including: a first connector 231 for connecting to the first electrode portion 223; and a second connector 232 for connecting to the first tab 211; the base metals of the first connector 231 and the second connector 232 are different; the first connector 231 and the second connector 232 are welded to form a first solder mark 241, the shape of the first solder mark 241 being an annular shape with a first opening 2411.

[0154] The first solder mark 241 is annular in shape with multiple first openings 2411. In the projection plane perpendicular to the thickness direction of the current collector 23, the sum of the central angles α formed by the geometric centers of the orthographic projections of the first solder mark 241 and the orthographic projections of the second connector 232 satisfies: 180° ≤ α < 360°. The first connector 231 and the second connector 232 are stacked along the thickness direction of the current collector 23. The first connector 231 is annular, and the second connector 232 includes a first part 2321 and a second part 2322. The first part 2321 is used for welding to the first connector 231 and is disposed around the outer periphery of the second part 2322. The second part 2322 is provided with a through-hole area 2323 and a connection area 2324, which is used for connection to the first tab 211.

[0155] The first connector 231 is provided with a first groove 2311. In a projection plane perpendicular to the thickness direction of the current collecting member 23, the orthographic projection of the first groove 2311 at least partially overlaps with the orthographic projection of the first opening 2411. The first solder mark 241 is annular in shape with multiple first openings 2411. The first connector 231 has multiple first grooves 2311, and the multiple first openings 2411 and multiple first grooves 2311 correspond one-to-one. The second connector 232 is provided with a second groove 23211, and the second groove 23211 and the first groove 2311 are stacked along the thickness direction of the current collecting member 23.

[0156] The first electrode portion 223 is welded to the first connector 231 to form a second solder mark 242. In the projection plane perpendicular to the thickness direction of the current collector 23, the second solder mark 242 is farther away from the geometric center of the orthographic projection of the first connector 231 compared to the first solder mark 241. The second solder mark 242 is annular with a third opening 2421. In the projection plane perpendicular to the thickness direction of the current collector 23, the third opening 2421 is offset from the first opening 2411. In the projection plane perpendicular to the thickness direction of the current collector 23, the sum of the central angles β formed by the orthographic projection of the second solder mark 242 relative to the geometric center of the orthographic projection of the first connector 231 satisfies: 160°≤β≤300°.

[0157] The first connector 231 is annular in shape, and / or the second connector 232 is disc-shaped; the first solder mark 241 is annular with a first opening 2411. The current collector 23 satisfies at least one of the following conditions: the outer diameter of the first connector 231 is in the range of [20mm, 80mm]; the inner diameter of the first connector 231 is in the range of [10mm, 70mm]; the thickness of the first connector 231 is in the range of [0.1mm, 3mm]; the diameter of the second connector 232 is in the range of [20mm, 80mm]; and the thickness of the second connector 232 is in the range of [0.1mm, 3mm]. The base metal of the first connector 231 is steel or aluminum; the base metal of the second connector 232 is copper. The electrode assembly 21 also includes a second electrode 212 with the opposite polarity to the first electrode 211. The first electrode 211 and the second electrode 212 are located at the two ends of the electrode assembly 21, respectively. The housing 22 includes a shell 221 and an end cap 222. The shell 221 is used to accommodate the electrode assembly 21 and has a hollow structure with a fourth opening 2211. The end cap 222 is connected to the shell 221 to cover the fourth opening 2211. The first electrode part 223 is either the end cap 222 or the shell 221. The housing 22 also includes a second electrode part 224, which is insulated through the bottom wall 2212 of the shell 221 and electrically connected to the second electrode 212.

[0158] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, include: Electrode assembly (21), including first electrode tab (211); A housing (22) for accommodating the electrode assembly (21), the housing (22) being provided with a first electrode portion (223); The current collection component (23) includes: The first connector (231) is used to connect to the first electrode part (223); as well as A second connector (232) is used to connect to the first tab (211); the base metal of the first connector (231) and the second connector (232) is different; the first connector (231) and the second connector (232) are welded to form a first solder mark (241), the shape of the first solder mark (241) is an annular shape with a first opening (2411).

2. The battery cell according to claim 1, characterized in that, The first solder mark (241) is an annular shape with multiple first openings (2411).

3. The battery cell according to claim 1, characterized in that, In the projection plane perpendicular to the thickness direction of the current collector (23), the sum of the central angles α formed by the geometric center of the orthographic projection of the first solder mark (241) relative to the orthographic projection of the second connector (232) satisfies: 180°≤α<360°.

4. The battery cell according to claim 1, characterized in that, The first connector (231) and the second connector (232) are stacked along the thickness direction of the current collection member (23).

5. The battery cell according to claim 4, characterized in that, The first connector (231) is annular. The second connector (232) includes a first part (2321) and a second part (2322). The first part (2321) is used to weld to the first connector (231). The first part (2321) is arranged around the outer periphery of the second part (2322). The second part (2322) is provided with a through hole area (2323) and a connection area (2324). The connection area (2324) is used to connect to the first tab (211).

6. The battery cell according to claim 5, characterized in that, The through-hole area (2323) passes through the geometric center of the second connector (232); and / or, The through-hole area (2323) is symmetrically distributed with respect to the geometric center of the second connector (232).

7. The battery cell according to claim 5, characterized in that, The through-hole area (2323) includes a positioning hole (2325).

8. The battery cell according to claim 5, characterized in that, The first connector (231) is provided with a first groove (2311), and in the projection plane perpendicular to the thickness direction of the current collecting member (23), the orthographic projection of the first groove (2311) at least partially overlaps with the orthographic projection of the first opening (2411).

9. The battery cell according to claim 8, characterized in that, The orthographic projection of the first groove (2311) is located within the orthographic projection of the first opening (2411).

10. The battery cell according to claim 8, characterized in that, The first solder mark (241) is an annular shape with multiple first openings (2411), and the first connector (231) is provided with multiple first grooves (2311). The multiple first openings (2411) and the multiple first grooves (2311) correspond one-to-one.

11. The battery cell according to claim 8, characterized in that, The number of the first groove (2311) ranges from [1, 10].

12. The battery cell according to claim 8, characterized in that, The second connector (232) is provided with a second groove (23211), and the second groove (23211) and the first groove (2311) are stacked together along the thickness direction of the current collection member (23).

13. The battery cell according to claim 1, characterized in that, The first electrode portion (223) is welded to the first connector (231) to form a second solder mark (242); In the projection plane perpendicular to the thickness direction of the current collector (23), the second solder mark (242) is farther away from the geometric center of the orthographic projection of the first connector (231) than the first solder mark (241).

14. The battery cell according to claim 13, characterized in that, The second solder mark (242) is annular in shape with a third opening (2421); In the projection plane perpendicular to the thickness direction of the current collecting member (23), the third opening (2421) is offset from the first opening (2411).

15. The battery cell according to claim 13, characterized in that, In the projection plane perpendicular to the thickness direction of the current collector (23), the sum of the central angles β formed by the geometric center of the orthographic projection of the second solder mark (242) relative to the orthographic projection of the first connector (231) satisfies: 160°≤β≤300°.

16. The battery cell according to any one of claims 1 to 15, characterized in that, The first connector (231) is annular in shape, and / or the second connector (232) is disc in shape; The first solder mark (241) is a ring with the first opening (2411).

17. The battery cell according to claim 16, characterized in that, The current collection component (23) satisfies at least one of the following conditions: The outer diameter of the first connector (231) is in the range of [20mm, 80mm]; The inner diameter of the first connector (231) is in the range of [10mm, 70mm]; The thickness of the first connector (231) ranges from [0.1mm, 3mm]; The diameter of the second connector (232) ranges from [20mm, 80mm]; and, The thickness of the second connector (232) ranges from [0.1mm to 3mm].

18. The battery cell according to any one of claims 1 to 15, characterized in that, The base metal of the first connector (231) is steel or aluminum; the base metal of the second connector (232) is copper.

19. The battery cell according to any one of claims 1 to 15, characterized in that, The electrode assembly (21) further includes a second electrode (212) with the opposite polarity to the first electrode (211), wherein the first electrode (211) and the second electrode (212) are located at opposite ends of the electrode assembly (21). The outer casing (22) includes a housing (221) and an end cap (222). The housing (221) is used to accommodate the electrode assembly (21). The housing (221) is a hollow structure with a fourth opening (2211). The end cap (222) is connected to the housing (221) to cover the fourth opening (2211). The first electrode part (223) is either the end cap (222) or the housing (221). The outer casing (22) further includes a second electrode portion (224), which is insulated through the bottom wall (2212) of the casing (221) and electrically connected to the second electrode tab (212).

20. A battery device, characterized in that, include: Multiple battery cells, wherein the battery cells are battery cells as described in any one of claims 1 to 19.

21. An electrical appliance, characterized in that, include: A battery device comprising a battery cell as described in any one of claims 1 to 19, the battery device being used to supply power to the electrical device.

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