Battery cell, preparation method, manufacturing equipment, battery device and power-using device

Abstract

The present application provides a battery cell, a preparation method, a manufacturing equipment, a battery device and an electrical device, which belongs to the field of battery technology. The present application provides a battery cell, which includes an electrode assembly, a support gasket and an electrode terminal. The electrode assembly includes a plurality of first pole ears stacked along a first direction; the support gasket is stacked with the plurality of first pole ears along the first direction, and the support gasket is connected to the plurality of first pole ears through a first welding portion; and the electrode terminal is connected to the plurality of first pole ears and the support gasket through a second welding portion; wherein the projections of the first welding portion and the second welding portion on a plane perpendicular to the first direction at least partially overlap. In this way, the connection reliability between the pole ears and the connecting terminals can be improved, and the presence of the support gasket can provide support for the first pole ears and improve the current carrying capacity of the first pole ears, which is beneficial to improving the energy density of the battery.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery cell, a preparation method, a manufacturing device, a battery device, and an electrical device. Background Art

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

[0003] During the battery manufacturing process, the tab welding of the battery cell is a very important process. The quality of welding not only affects the reliability of the tab connection, but also affects the current carrying capacity of the tab. Summary of the Invention

[0004] The present application aims to solve at least one of the technical problems in the background art. To this end, one object of the present application is to provide a battery cell, a preparation method, a battery manufacturing device, a battery device, and an electrical device to improve the reliability of the battery tab connection.

[0005] Embodiments of the first aspect of the present application provide a battery cell. The battery cell includes an electrode assembly, a support gasket, and an electrode terminal. The electrode assembly includes a plurality of first electrode tabs stacked along a first direction; the support gasket is stacked with the plurality of first electrode tabs along the first direction X, the support gasket and the plurality of first electrode tabs being connected via a first weld; and the electrode terminal is connected to the plurality of first electrode tabs and the support gasket via a second weld; wherein the projections of the first weld and the second weld on a plane perpendicular to the first direction X at least partially overlap.

[0006] In the technical solution of the embodiment of the present application, a first weld is formed between the support gasket and the plurality of first electrode tabs to achieve electrical connection between the first electrode tabs, and a second weld enables electrical connection between the electrode terminal, the plurality of first electrode tabs, and the electrode terminal. The connection between the plurality of first electrode tabs, the support gasket, and the electrode terminal via the at least partially overlapping first and second welds helps improve the reliability of the electrical connection between the plurality of electrode tabs and the electrode terminal, while also enhancing the current flow capacity between the electrode tabs and the electrode terminal. Furthermore, the provision of the support gasket provides support for the first weld formed by welding the plurality of first electrode tabs, reducing the probability of cold welds and achieving a more reliable connection.

[0007] In some embodiments, the projection of the second weld onto a plane perpendicular to the first direction completely falls within the projection of the first weld onto the plane. This reduces the force acting on the first tab at the edge of the first weld when forming the second weld, thereby reducing the risk of cracks in the first tab and improving the reliability of the connection between the first tab and the electrode terminal.

[0008] In some embodiments, the first weld is formed by a first welding method, and the second weld is formed by a second welding method; wherein the welding energy of the first welding method is less than the welding energy of the second welding method. The lower welding energy of the first welding method than the second welding method helps protect the first tab, reduces the risk of cracking in the first tab, and improves the reliability of the weld connection.

[0009] In some embodiments, the first welding method is ultrasonic welding, and the second welding method is laser welding. Selecting the appropriate welding method based on the welding object can improve the welding quality between the multiple first tabs and between the multiple first tabs and the electrode terminal, reduce the risk of welding cracks in the first tabs, and improve the current carrying capacity of the welded tabs.

[0010] In some embodiments, the plurality of first tabs are located on one side of the support pad, and the electrode terminals are located on the other side of the support pad. Thus, the plurality of first tabs and the electrode terminals are respectively arranged on both sides of the support pad, which facilitates welding and improves the welding efficiency of the first tabs and the electrode terminals.

[0011] In some embodiments, a portion of the plurality of first tabs is located on the side of the support pad away from the electrode terminal, while another portion of the plurality of first tabs is located on the side of the support pad facing the electrode terminal. This can increase the contact area between the first tabs and the support pad, achieve more uniform heat distribution and higher weld quality, and improve the mechanical strength of the weld and the stability of the electrical connection.

[0012] In some embodiments, the support pad has a thickness greater than or equal to 0.2 mm and less than or equal to 0.5 mm. The thickness of the support pad is between 0.2 mm and 0.5 mm to enable better welding and improve weld quality, thereby increasing reliability of the connection between the first tab and the electrode terminal.

[0013] In some embodiments, the electrode assembly includes a first electrode sheet and a second electrode sheet alternately stacked along a first direction; the first electrode sheet includes a current collector and an active material layer located on at least one surface of the current collector, with the current collector extending beyond the active material layer to form a first electrode tab. Current transmission can be achieved by stacking the first and second electrode sheets and connecting them to different electrode terminals.

[0014] An embodiment of a second aspect of the present application provides a method for preparing a battery cell, the method comprising: providing an electrode assembly, the electrode assembly comprising a plurality of first tabs stacked along a first direction; welding the plurality of first tabs to form a first weld, the method comprising: providing a support washer stacked with the plurality of first tabs along a first direction X; welding the plurality of first tabs and the support washer to form the first weld; providing an electrode terminal; and welding the electrode terminal to the plurality of first tabs and the support washer to form a second weld, wherein the projections of the first weld and the second weld on a plane perpendicular to the first direction at least partially overlap. The connection between the plurality of first tabs, the support washer, and the electrode terminal via the at least partially overlapping first and second welds helps improve the reliability of the electrical connection between the plurality of first tabs and the electrode terminal and enhances welding and fixing efficiency.

[0015] In some embodiments, welding the plurality of first electrode tabs to the support washer to form the first weld includes: placing all of the plurality of first electrode tabs on one side of the support washer and welding to form the first weld; or placing a portion of the plurality of first electrode tabs on one side of the support washer and another portion of the plurality of first electrode tabs on the other side of the support washer and welding to form the first weld. This can achieve more uniform heat distribution and higher weld quality, improve the mechanical strength of the weld and the stability of the electrical connection, and thus improve the welding efficiency of the first electrode tab and the electrode terminal.

[0016] In some embodiments, the projection of the second weld on a plane perpendicular to the first direction completely falls within the projection of the first weld on the plane. This can improve the ability to transfer current between the first tab and the electrode terminal, thereby reducing the risk of cracks in the first tab and improving the reliability of the connection between the first tab and the electrode terminal.

[0017] In some embodiments, the first weld is formed by a first welding method, and the second weld is formed by a second welding method; wherein the welding energy of the first welding method is less than the welding energy of the second welding method. This helps protect the first tab and improves the reliability of the weld connection.

[0018] In some embodiments, the first welding method is ultrasonic welding, and the second welding method is laser welding. This helps improve the welding quality between the multiple first tabs and between the multiple first tabs and the electrode terminals, reduces the risk of welding cracks in the first tabs, and improves the current carrying capacity of the welded tabs.

[0019] An embodiment of the third aspect of the present application provides a battery manufacturing device, which includes a first supply assembly, a second supply assembly, a first welding assembly, and a second welding assembly. The first supply assembly is configured to provide an electrode assembly and an electrode terminal, wherein the electrode assembly includes a plurality of first tabs stacked along a first direction; the second supply assembly is configured to provide a support gasket, which is stacked with the plurality of first tabs along a first direction X; the first welding assembly is configured to weld the support gasket to the plurality of first tabs to form a first weld; the second welding assembly is configured to weld the electrode terminal to the plurality of first tabs and the support gasket to form a second weld, wherein the projections of the first weld and the second weld on a plane perpendicular to the first direction at least partially overlap. This helps to improve the reliability of the electrical connection between the plurality of first tabs and the electrode terminal, while also improving the flow capacity between the first tabs and the electrode terminal.

[0020] In some embodiments, the welding energy output by the first welding assembly is less than the welding energy output by the second welding assembly, thereby facilitating protection of the first tab, reducing the risk of cracks in the first tab, and improving reliability of the weld connection.

[0021] In some embodiments, the first welding assembly is an ultrasonic welding assembly, and the second welding assembly is a laser welding assembly. This helps improve the welding quality between the multiple first electrode tabs and between the multiple first electrode tabs and the electrode terminals, reduces the risk of welding cracks in the first electrode tabs, and improves the current carrying capacity of the welded first electrode tabs.

[0022] An embodiment of a fourth aspect of the present application provides a battery device, which includes the battery cell in the above embodiment.

[0023] An embodiment of the fifth aspect of the present application provides an electrical device, which includes the battery device in the above embodiment, and the battery device is used to provide electrical energy.

[0024] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar components or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in this application and should not be construed as limiting the scope of this application.

[0026] Figure 1 A schematic structural diagram of a vehicle according to some embodiments of the present application;

[0027] Figure 2 Schematic diagram of the exploded structure of batteries according to some embodiments of the present application;

[0028] Figure 3 This is one of the structural schematic diagrams of a battery cell in some embodiments of the present application;

[0029] Figure 4 This is a schematic structural diagram of an electrode assembly according to some embodiments of the present application;

[0030] Figure 5 This is the second structural diagram of a battery cell according to some embodiments of the present application;

[0031] Figure 6 for Figure 5 A partial enlarged view of

[0032] Figure 7 This is the third structural diagram of a battery cell according to some embodiments of the present application;

[0033] Figure 8 for Figure 7 A partial enlarged view of

[0034] Figure 9 A flow chart of a method for preparing a battery cell according to some embodiments of the present application;

[0035] Figure 10 This is a structural block diagram of battery manufacturing equipment according to some embodiments of the present application.

[0036] Description of reference numerals:

[0037] Vehicles 1000;

[0038] Battery 100, controller 200, motor 300;

[0039] Box body 10, first part 11, second part 12;

[0040] Battery cell 20, electrode assembly 21, first electrode tab 211, housing 22, end cap 23;

[0041] Electrode terminal 30, first welding portion 40, second welding portion 50, support gasket 60;

[0042] Battery manufacturing equipment 700, first providing assembly 710, first welding assembly 720, second welding assembly 730, second providing assembly 740;

[0043] The first direction X. DETAILED DESCRIPTION

[0044] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0046] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0047] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0048] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0049] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0050] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0051] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0052] Currently, market developments indicate that power batteries are becoming increasingly widely used. They are not only used in energy storage systems such as hydropower, thermal, wind, and solar power plants, but are also widely used in electric vehicles like electric bicycles, electric motorcycles, and electric vehicles, as well as in military equipment and aerospace. As power battery applications continue to expand, market demand is also growing.

[0053] Tabs are metallic conductors extending from the electrode sheets of an electrode assembly. They connect to the electrode terminals on the battery casing. Current must flow through the tabs and the electrode terminals to establish a connection with the outside of the battery. During battery manufacturing, the tabs and electrode terminals can be melted together using high temperatures through welding. Common welding methods include laser welding, ultrasonic welding, and resistance heat welding.

[0054] Tab welding is a critical process in battery manufacturing, and its welding quality directly affects battery performance and reliability. Due to the thinness of the tab, excessive welding energy applied when welding the tab to the terminal can cause cracks in the tab, affecting the reliability of the connection between the tab and the terminal. Furthermore, insufficient tab overcurrent during the tab-to-terminal welding process can limit the energy density of the battery cell.

[0055] Based on this, the present application provides a battery cell, which includes an electrode assembly, a support gasket, and an electrode terminal. The electrode assembly includes a plurality of first pole tabs stacked along a first direction; the support gasket is stacked with the plurality of first pole tabs along the first direction, and the support gasket is connected to the plurality of first pole tabs via a first weld; and the electrode terminal is connected to the plurality of first pole tabs and the support gasket via a second weld; wherein the projections of the first weld and the second weld on a plane perpendicular to the first direction at least partially overlap. The plurality of first pole tabs are connected to the support gasket and the electrode terminal via the at least partially overlapping first weld and second welds, so that the weld marks of the first weld can be directly utilized to improve the connection strength of the second weld, thereby improving the connection reliability of the first pole tab and the connection terminal. In addition, the presence of the support gasket can provide support for the first pole tab and improve the current carrying capacity of the first pole tab, which is beneficial to improving the energy density of the battery.

[0056] The battery cells disclosed in the embodiments of the present application can be used, but are not limited to, in electrical devices such as vehicles, ships, or aircraft. A power supply system comprising the battery cells and batteries disclosed in the present application can be used to form the electrical device.

[0057] The present invention provides an electric device that uses a battery as a power source. The electric device may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery-powered vehicle, an electric car, a ship, a spacecraft, etc. The electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc. The spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0058] For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device according to an embodiment of the present application.

[0059] Please refer to Figure 1 , Figure 1 A schematic diagram of the structure of a vehicle provided for some embodiments of the present application. The vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 can be provided at the bottom, head or tail of the vehicle 1000. The battery 100 can be used to power the vehicle 1000. For example, the battery 100 can serve as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0060] In some embodiments of the present application, the battery 100 can serve not only as an operating power source for the vehicle 1000, but also as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0061] Please refer to Figure 2 , Figure 2 This is a schematic diagram of the exploded structure of a battery provided in some embodiments of the present application. The battery 100 includes a housing 10 and a battery cell 20, with the battery cell 20 housed within the housing 10. The housing 10 is used to provide a storage space for the battery cell 20, and the housing 10 can have a variety of structures. In some embodiments, the housing 10 can include a first portion 11 and a second portion 12, which overlap each other and together define a storage space for the battery cell 20. The second portion 12 can be a hollow structure with one end open, and the first portion 11 can be a plate-like structure, with the first portion 11 overlapping the open side of the second portion 12, so that the first portion 11 and the second portion 12 together define a storage space. The first portion 11 and the second portion 12 can also be hollow structures with one end open, with the open side of the first portion 11 overlapping the open side of the second portion 12. Of course, the housing 10 formed by the first portion 11 and the second portion 12 can have a variety of shapes, such as a cylinder, a rectangular parallelepiped, etc.

[0062] In the battery 100, there may be multiple battery cells 20, and the multiple battery cells 20 may be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections among the multiple battery cells 20. The multiple battery cells 20 may be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery cell 20 may be housed within the housing 10. Alternatively, the battery 100 may be constructed by first connecting multiple battery cells 20 in series, in parallel, or in a hybrid connection to form a battery module, which is then connected in series, in parallel, or in a hybrid connection to form a complete battery module, and then housed within the housing 10. The battery 100 may also include other structures, such as a busbar assembly for electrically connecting the multiple battery cells 20.

[0063] Each battery cell 20 may be a secondary battery or a primary battery, and may also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 20 may be cylindrical, flat, rectangular, or in other shapes.

[0064] like Figure 3-10 For example, Figure 3 This is one of the structural schematic diagrams of a battery cell in some embodiments of the present application; Figure 4 This is a schematic structural diagram of an electrode assembly according to some embodiments of the present application; Figure 5 This is the second structural diagram of a battery cell according to some embodiments of the present application; Figure 6 for Figure 5 A partial enlarged view of Figure 7 This is the third structural diagram of a battery cell according to some embodiments of the present application; Figure 8 for Figure 7 A partial enlarged view of Figure 9 A flow chart of a method for preparing a battery cell according to some embodiments of the present application; Figure 10 This is a structural block diagram of battery manufacturing equipment according to some embodiments of the present application.

[0065] An embodiment of the present application provides a battery cell 20, comprising an electrode assembly 21, a support gasket 60, and an electrode terminal 30. The electrode assembly 21 comprises a plurality of first electrode tabs 211 stacked along a first direction X; the support gasket 60 is stacked along the first direction X with the plurality of first electrode tabs 211, the support gasket 60 being connected to the plurality of first electrode tabs 211 via a first weld 40; and the electrode terminal 30 is connected to the plurality of first electrode tabs 211 and the support gasket 60 via a second weld 50; wherein the projections of the first weld 40 and the second weld 50 on a plane perpendicular to the first direction X at least partially overlap.

[0066] like Figure 3 As shown, the electrode assembly 21 is a component in the battery cell 20 where electrochemical reactions occur. The electrode assembly 21 is arranged in the shell 22 of the battery cell 20, and the shell 22 may contain one or more electrode assemblies 21. The electrode assembly 21 is mainly formed by winding or stacking the positive electrode sheet and the negative electrode sheet, and a separator is usually provided between the positive electrode sheet and the negative electrode sheet. The parts of the positive electrode sheet and the negative electrode sheet with active materials constitute the main body of the battery cell assembly, and the parts of the positive electrode sheet and the negative electrode sheet without active materials each constitute the tab. The positive electrode tab and the negative electrode tab may be located together at one end of the main body or respectively at both ends of the main body. During the charge and discharge process of the battery, the positive electrode active material and the negative electrode active material react with the electrolyte, and the tabs connect the electrode terminals to form a current loop. The first tab 211 can be a positive electrode tab or a negative electrode tab.

[0067] The first pole tab 211 can be a portion of foil extending from the current collector of the pole piece. The multiple first pole tabs 211 extending from the pole piece after winding are stacked along the first direction, which means that the foil materials extending from multiple winding layers as the first pole tabs are stacked along the first direction X, and the first direction is parallel to the thickness direction of the first pole tab 211.

[0068] The support gasket 60 is a sheet-like structure. The material of the support gasket 60 can be a conductive metal, such as copper, copper alloy, aluminum or aluminum alloy, etc., which is not limited in this embodiment.

[0069] The electrode terminal 30 may be a post disposed on the end cap 23. The end cap 23 is a component that cooperates with the housing 22 to form an internal environment for the battery cell 20. The electrode terminal 30 may be used to electrically connect to the tab of the electrode assembly 21 to output or input electrical energy to or from the battery cell 20.

[0070] The first weld 40 is a tightly connected structure formed by heat, pressure, or a combination of both, between the plurality of first electrode tabs 211. The first weld 40 can achieve mechanical and electrical connections between the plurality of first electrode tabs 211. In some embodiments, the first weld 40 can be formed by welding.

[0071] The second weld 50 is a tightly connected structure formed between the first electrode tab 211 and the electrode terminal 30 by heat, pressure, or a combination of both. The second weld 50 can achieve mechanical and electrical connections between the plurality of first electrode tabs 211 and the electrode terminal 30. In some embodiments, the second weld 50 can be formed by welding.

[0072] In some examples, to reduce the mutual influence, the first weld 40 and the second weld 50 on the support gasket 60 are staggered. However, this will cause the current on the tab to pass through the support gasket to achieve flow, thereby limiting the current flow capacity of the tab. In the embodiment of the present application, the support gasket 60 can be connected to multiple first tabs 211 through the first weld 40 and to the electrode terminal 30 through the second weld 50. The first weld 40 and the second weld 50 at least partially overlap. In this way, the current on the first tab 211 can flow directly to the electrode terminal 30 through the first weld 40 and the second weld 50. In addition, the presence of the support gasket 60 can increase the weld footprint size of the first weld 40 and the second weld 50, thereby solving the problem of insufficient current flow capacity of the tab welding. Moreover, since the current can flow from the first tab 211 to the electrode terminal 30, the size requirement of the support gasket 60 can be reduced, and the layout space of the support gasket 60 can be reduced, thereby improving the energy density of the battery cell 20.

[0073] In some embodiments, there may be multiple support pads 60, and the multiple support pads 60 are alternately arranged with the first electrode tabs along the first direction, thereby providing more uniform support and a more sufficient flow area for the multiple first electrode tabs 211. For example, the number of support pads 60 is only one less than the number of first electrode tabs 211, and any support pad is located between two adjacent first electrode tabs 211.

[0074] The projections of the first weld 40 and the second weld 50 on a plane perpendicular to the first direction X at least partially overlap, including cross-overlap and full overlap. In some embodiments, the projections of the first weld 40 and the second weld 50 on a plane perpendicular to the first direction X cross-overlap. In other embodiments, the full overlap of the projections of the first weld 40 and the second weld 50 includes: the projection of the first weld 40 on a plane perpendicular to the first direction X completely falls within the projection of the second weld 50, the projection of the second weld 50 on a plane perpendicular to the first direction X completely falls within the projection of the first weld 40, or the projections of the first weld 40 and the second weld 50 on a plane perpendicular to the first direction X completely overlap.

[0075] Because the first tab 211 is a very thin sheet, insufficient welding energy during the connection of multiple first tabs 211 to the electrode terminal 30 may result in a cold weld. Excessive welding energy can easily crack the weld edge, thus affecting the reliability of the tab connection. In some embodiments, a portion of the first weld 40 can be positioned within the welding region used to form the second weld 50. This allows the already formed first weld 40 to be welded to the electrode terminal 30 to form the second weld 50. In this case, the presence of the support gasket 60 significantly increases the thickness of the first weld 40 compared to a single first tab 211, reducing the likelihood of cracks during welding and achieving a more reliable connection. Furthermore, the partial overlap between the first weld 40 and the second weld 50 effectively means that at least a portion of the first weld 40 is directly fused to the electrode terminal 30, resolving the problem of insufficient flow due to the narrowness of the welded tab.

[0076] The first welds 40 formed between the plurality of first electrode tabs 211 enable electrical connection between the first electrode tabs 211, and the second welds 50 enable electrical connection between the plurality of electrode tabs and the electrode terminal 30. The overlap of the first welds 40 and the second welds 50 projected on a specific plane helps improve the reliability of the electrical connection between the plurality of first electrode tabs 211 and the electrode terminal 30, while also enhancing the current flow capacity between the first electrode tabs 211 and the electrode terminal 30.

[0077] According to some embodiments of the present application, a projection of the second weld portion 50 on a plane perpendicular to the first direction X completely falls within a projection range of the first weld portion 40 on the plane.

[0078] In some embodiments, at least a portion of the first welding portion 40 can be directly connected to the electrode terminal 30 to form the second welding portion 50. For example, at least a portion of the first welding portion 40 and the electrode terminal 30 are melt-welded to form the second welding portion 50, so that the weld mark of the second welding portion 50 completely falls within the projection range of the weld mark of the first welding portion 40.

[0079] The projection of the second weld portion 50 completely falls within the projection range of the first weld portion 40. In this way, when the second weld portion 50 is formed, the force acting on the first pole tab 211 at the edge of the first weld portion 40 can be reduced, thereby reducing the risk of cracks in the first pole tab 211 and improving the reliability of the connection between the pole tab and the electrode terminal.

[0080] According to some embodiments of the present application, the first weld portion 40 is formed by a first welding method, and the second weld portion 50 is formed by a second welding method; wherein the welding energy of the first welding method is less than the welding energy of the second welding method.

[0081] The first welding method is used to weld the plurality of first electrode tabs 211 to form the first welded portion 40, and the second welding method is used to weld the plurality of first electrode tabs 211 to the electrode terminal 30 to form the second welded portion 50. The first welding method and the second welding method may be the same welding method or different welding methods.

[0082] Welding energy refers to the amount of heat input per unit length of the weld during welding. Since the tab material is typically thin, the first welding method with lower welding energy can be used. Since the electrode terminal 30 (e.g., the post) is thicker than the tab, the second weld 50 formed between the two must withstand a higher strength connection and a higher current. Therefore, the second welding method requires higher welding energy to meet these requirements.

[0083] For commonly used welding methods, such as ultrasonic welding and laser welding, the welding energy is calculated as follows: For ultrasonic welding, welding energy usually refers to the energy applied to the weld joint per unit time during the welding process. The calculation formula is: ;

[0084] Where E represents welding energy in joules (J); P represents welding power in watts (W); and t represents welding time in seconds (s). In addition, the calculation formula for ultrasonic welding power is: ,in is the ultrasonic frequency, A is the amplitude of the welding head, ΔT is the frictional heat generated on the surface of the welding head, and δ is the contact pressure between the welding head and the workpiece surface.

[0085] For laser welding, welding energy is the total energy transferred by the laser beam to the welding material during the welding process, and welding power is the energy transferred by the laser beam to the welding material per unit time during the laser welding process, usually expressed in watts (W). The formula for calculating the welding energy of laser welding is: ;

[0086] Where E is the welding energy, measured in joules (J); P is the laser welding power, which is the energy transferred to the welding material by the laser beam per unit time during the laser welding process, measured in watts (W); and t is the time required for welding, usually expressed in seconds (s).

[0087] In some embodiments, the first electrode tabs 211 may be welded to form the first weld portion 40 using a first welding method with lower welding energy, and then the first weld portion 40 and the electrode terminal 30 may be welded to form the second weld portion 50 using a second welding method with higher welding energy.

[0088] The welding method of this embodiment is beneficial for protecting the first electrode tab 211 , reducing the risk of cracks in the first electrode tab 211 , and improving the reliability of the welding connection.

[0089] According to some embodiments of the present application, the first welding method is ultrasonic welding, and the second welding method is laser welding.

[0090] Ultrasonic welding utilizes heat energy generated by high-frequency vibrations. Ultrasonic energy is transmitted to the contact surfaces of the workpieces, generating heat due to friction and ultimately joining the materials. This welding method is particularly suitable for welding thin metals such as tabs, reducing the risk of cracks.

[0091] Laser welding uses a high-energy laser beam as a heat source to locally heat and melt the material, forming a molten pool or keyhole to achieve a connection. Laser welding is suitable for a wide range of materials, including joining dissimilar metals. Laser welding offers advantages such as high energy density, concentrated heating, fast welding speeds, and minimal weld distortion. Laser welding, as a second welding method, can achieve weld marks with higher joint strength and greater current carrying capacity.

[0092] Selecting corresponding welding methods according to different welding objects is beneficial to improving the welding quality between multiple first electrode tabs 211 and between multiple first electrode tabs 211 and electrode terminals 30, reducing the risk of welding cracks in the first electrode tabs 211, and improving the current capacity of the electrode tabs after welding.

[0093] Since the first electrode tabs 211 are relatively thin, the support gasket 60 can provide support for welding the first electrode tabs 211 to form the first weld 40 without affecting the flow capacity, thereby reducing the probability of cold welding and achieving a more reliable connection.

[0094] According to some embodiments of the present application, the plurality of first electrode tabs 211 are located on one side of the support gasket 60 , and the electrode terminal 30 is located on the other side of the support gasket 60 .

[0095] like Figure 5 and Figure 6In an example, a plurality of first pole tabs 211, a support gasket 60 and an electrode terminal 30 are respectively placed along a first direction X, and the plurality of first pole tabs 211 and the support gasket 60 can be connected and fixed by a first welding portion 40 by ultrasonic welding, and then the support gasket 60 and the electrode terminal 30 are fixedly connected by forming a second welding portion 50 by laser welding, wherein the projections of the first welding portion 40 and the second welding portion 50 on a plane perpendicular to the first direction X at least partially overlap.

[0096] The plurality of first electrode tabs 211 and electrode terminals 30 are respectively arranged on both sides of the support gasket 60 , which is conducive to welding, thereby improving the welding efficiency of the first electrode tabs 211 and the electrode terminals 30 .

[0097] According to some embodiments of the present application, a portion of the plurality of first electrode tabs 211 is located on a side of the support gasket 60 away from the electrode terminal 30 , and another portion of the plurality of first electrode tabs 211 is located on a side of the support gasket 60 facing the electrode terminal 30 .

[0098] like Figure 7 and Figure 8 In an example, a portion of the plurality of first pole tabs 211, a support gasket 60, another portion of the plurality of first pole tabs 211, and the electrode terminal 30 are respectively placed along the first direction X, that is, the support gasket 60 is connected and fixed to the middle position of the plurality of first pole tabs 211 through the first welding portion 40 by ultrasonic welding, and then the support gasket 60 and the electrode terminal 30 are fixedly connected through the second welding portion 50 by laser welding, wherein the projections of the first welding portion 40 and the second welding portion 50 on the plane perpendicular to the first direction X at least partially overlap.

[0099] The support gasket 60 is welded to the middle position of the plurality of first tabs 211 , which can increase the contact area between the first tabs 211 and the support gasket 60 , achieve more uniform heat distribution and higher weld quality, and improve the mechanical strength of the welding point and the stability of the electrical connection.

[0100] According to some embodiments of the present application, the thickness of the support pad 60 is greater than or equal to 0.2 mm and less than or equal to 0.5 mm.

[0101] The thickness of the support gasket 60 is defined as the dimension along the first direction X. In some examples, an adapter plate can be provided to achieve electrical connection between the first tab 211 and the electrode terminal 30. In this case, the adapter plate has a requirement for overcurrent capacity, and its thickness is usually designed to be 0.6-0.8 mm, and sometimes even exceeds 0.8 mm. This places high requirements on the layout space of the adapter plate, and a too large thickness will also lead to an increase in weight, which is detrimental to the energy density of the battery.

[0102] In this embodiment, the support gasket 60 between the first tab 211 and the electrode terminal 30 is different from the commonly used adapter plate and does not need to be increased in thickness to meet the overcurrent requirements. Therefore, the thickness of the support gasket 60 can be designed to be thinner, such as 0.2 mm, 0.3 mm, 0.4 mm or 0.5 mm. This can take into account improving the weld quality, improving the reliability of the tab connection and the overcurrent capacity of the tab.

[0103] According to some embodiments of the present application, the electrode assembly 21 includes a first electrode sheet and a second electrode sheet alternately stacked along a first direction X; the first electrode sheet includes a current collector and an active material layer located on at least one side surface of the current collector, and a portion of the current collector extends beyond the active material layer to form a first electrode ear 211.

[0104] The first electrode sheet may be a positive electrode sheet or a negative electrode sheet. In the electrode assembly 21 , the positive electrode sheets and the negative electrode sheets are alternately stacked and arranged along the first direction X.

[0105] The current collector is an essential component of a battery. It not only carries the active material but also collects and outputs the current generated by the electrode active material, helping to reduce the internal resistance of lithium-ion batteries and improve the battery's coulombic efficiency, cycling stability, and rate capability. Active materials are substances in the positive and negative electrodes of a battery that can participate in current-forming reactions. For positive electrode sheets, aluminum foil is commonly used as the current collector. Its thickness is generally between 10 and 20 microns, primarily rolled aluminum foil, which offers excellent electrical conductivity and chemical stability. Common active materials for positive electrode sheets include, but are not limited to, lithium cobalt oxide, lithium manganese oxide, ternary materials, or lithium iron phosphate. For negative electrode sheets, copper foil is commonly used as the current collector. Its thickness is generally between 6 and 8 microns, primarily electrolytic copper foil, which offers high electrical conductivity and flexibility. Common active materials for negative electrode sheets include, but are not limited to, graphite, silicon-based materials, or carbon nanomaterials. In some embodiments, the first tab 211 can be the current collector for the positive electrode sheet or the portion of the current collector for the negative electrode sheet that extends beyond the active material layer.

[0106] In some embodiments, a separator is positioned between the stacked first and second electrode sheets. The separator's primary function is to separate the positive and negative electrodes of the battery while ensuring the passage of lithium ions, forming a charge-discharge circuit and preventing contact between the positive and negative electrodes, which could cause a short circuit. The separator is primarily made of polyolefins, such as polypropylene (PP) and polyethylene (PE).

[0107] Current transmission can be achieved by stacking the first pole piece and the second pole piece and connecting the first pole piece and the second pole piece to different electrode terminals 30 .

[0108] An embodiment of the second aspect of the present application provides a method for preparing a battery cell, the method comprising:

[0109] S101, providing an electrode assembly 21, wherein the electrode assembly 21 includes a plurality of first electrode tabs 211 stacked along a first direction X;

[0110] S102, welding a plurality of first electrode tabs 211 to form a first weld portion 40, including:

[0111] Providing a support gasket 60, the support gasket 60 is stacked with the plurality of first tabs 211 along the first direction X;

[0112] Welding the plurality of first electrode tabs 211 and the support pad 60 to form a first welded portion;

[0113] S103, providing electrode terminals 30;

[0114] S104 , welding the electrode terminal 30 , the plurality of first electrode tabs 211 , and the support gasket 60 to form a second weld portion 50 , wherein the projections of the first weld portion 40 and the second weld portion 50 on a plane perpendicular to the first direction X at least partially overlap.

[0115] In step S101, the electrode assembly 21 can be a wound cell formed by stacking and winding a first electrode sheet and a second electrode sheet with different polarities, or a laminated cell formed by stacking a first electrode sheet and a second electrode sheet with different polarities. The current collector of the first electrode sheet extends to form a first electrode tab, and the plurality of first electrode tabs are stacked along a first direction X, where the first direction is parallel to the thickness of the first electrode sheet.

[0116] In step S102, the support gasket 60 is a sheet-like structure. As a key component connecting the battery cover and the battery cell, it must simultaneously meet the requirements of current flow, strength, and low spatter. The support gasket 60 is connected to the first tabs 211 and the electrode terminals 30 through the first weld 40 and the second weld 50, respectively. Therefore, current can be directly transferred from the first tabs 211 to the electrode terminals 30 through the first weld 40 and the second weld 50.

[0117] In step S103 , the electrode terminal 30 may be a pole penetrating the end cap 23 , one end of the electrode terminal 30 is connected to the tab, and the other end is connected to the outside, thereby realizing charging or discharging of the battery.

[0118] In step S104, a plurality of first tabs 211 and electronic terminals are arranged along a first direction X and fused together by welding to form a second weld 50. The projections of the first weld 40 and the second weld 50 on a plane perpendicular to the first direction X at least partially overlap, including cross-overlap and full overlap. In some embodiments, the projections of the first weld 40 and the second weld 50 on a plane perpendicular to the first direction X cross-overlap. In other embodiments, the full overlap of the projections of the first weld 40 and the second weld 50 includes: the projection of the first weld 40 on a plane perpendicular to the first direction X falls entirely within the projection of the second weld 50, the projection of the second weld 50 on a plane perpendicular to the first direction X falls entirely within the projection of the first weld 40, or the projections of the first weld 40 and the second weld 50 on a plane perpendicular to the first direction X completely overlap.

[0119] In some embodiments, a portion of the first weld portion 40 may be disposed within a welding region for forming the second weld portion 50 , so that the already formed first weld portion 40 may be welded to the electrode terminal 30 to form the second weld portion 50 .

[0120] The first welds 40 formed between the plurality of first electrode tabs 211 enable electrical connection between the first electrode tabs 211, and the second welds 50 enable electrical connection between the plurality of electrode tabs and the electrode terminal 30. The connection between the plurality of first electrode tabs 211 and the support pad 60 and the electrode terminal 60 via the at least partially overlapping first and second welds helps improve the reliability of the electrical connection between the plurality of first electrode tabs 211 and the electrode terminal 30 and enhances welding and fixing efficiency.

[0121] According to some embodiments of the present application, welding multiple first pole tabs 211 to the support gasket 60 to form a first welding portion 40 includes: setting all of the multiple first pole tabs 211 on one side of the support gasket 60 and welding them to form the first welding portion 40; or setting a portion of the multiple first pole tabs 211 on one side of the support gasket 60, and setting another portion of the multiple first pole tabs 211 on the other side of the support gasket 60, and welding them to form the first welding portion 40.

[0122] In some embodiments, multiple first pole tabs 211, support gaskets 60 and electrode terminals 30 are respectively placed along the first direction X. The multiple first pole tabs 211 and support gaskets 60 can be connected and fixed with a first welding portion 40 by ultrasonic welding, and then the support gaskets 60 and the electrode terminals 30 are fixedly connected by laser welding to form a second welding portion 50.

[0123] In other embodiments, a portion of the multiple first pole tabs 211, a support gasket 60, another portion of the multiple first pole tabs 211, and the electrode terminal 30 are respectively placed along the first direction X, that is, the support gasket 60 is connected and fixed to the middle position of the multiple first pole tabs 211 through the first welding portion 40 by ultrasonic welding, and then the support gasket 60 and the electrode terminal 30 are fixedly connected through the second welding portion 50 by laser welding, wherein the projections of the first welding portion 40 and the second welding portion 50 on the plane perpendicular to the first direction X at least partially overlap.

[0124] Multiple pole tabs and electrode terminals 30 are respectively arranged on both sides of the support gasket 60 or the support gasket 60 is welded to the middle position of multiple first pole tabs 211. This can increase the contact area between the first pole tab 211 and the support gasket 60, achieve more uniform heat distribution and higher weld quality, improve the mechanical strength of the welding point and the stability of the electrical connection, thereby improving the welding efficiency of the first pole tab 211 and the electrode terminal 30.

[0125] According to some battery cell manufacturing methods of the present application, the projection of the second weld portion 50 on a plane perpendicular to the first direction X completely falls within the projection range of the first weld portion 40 on the plane.

[0126] In some embodiments, at least a portion of the first weld portion 40 may be melt-welded to the electrode terminal 30 to form the second weld portion 50 , so that the weld mark of the second weld portion 50 completely falls within the projection range of the weld mark of the first weld portion 40 .

[0127] During the welding process, the projection of the second weld portion 50 completely falls within the projection range of the first weld portion 40. In this way, when the second weld portion 50 is formed, the force on the first pole ear 211 at the edge of the first weld portion 40 can be reduced, and the ability to transfer current between the first pole ear 211 and the electrode terminal 30 can be improved, thereby reducing the risk of cracks in the first pole ear 211 and improving the reliability of the connection between the pole ear and the electrode terminal.

[0128] According to some embodiments of the present application, the first weld portion 40 is formed by a first welding method, and the second weld portion 50 is formed by a second welding method; wherein the welding energy of the first welding method is less than the welding energy of the second welding method.

[0129] In some embodiments, the first electrode tabs 211 may be welded to form the first weld portion 40 using a first welding method with lower welding energy, and then the first weld portion 40 and the electrode terminal 30 may be welded to form the second weld portion 50 using a second welding method with higher welding energy.

[0130] The use of different welding methods is beneficial to protecting the first electrode tab 211 , reducing the risk of cracks in the first electrode tab 211 , and improving the reliability of the welding connection.

[0131] According to some embodiments of the present application, the first welding method is ultrasonic welding, and the second welding method is laser welding.

[0132] Because the tab material is typically thin, the first welding method with lower welding energy can be used. Since the electrode terminal 30 (e.g., the post) is thicker than the tab, the second weld 50 formed between them needs to withstand a higher connection strength and a larger current. Therefore, the second welding method requires higher welding energy to meet these requirements. Therefore, ultrasonic welding is used as the first welding method, and laser welding is used as the second welding method.

[0133] Selecting corresponding welding methods according to different welding objects is beneficial to improving the welding quality between multiple first electrode tabs 211 and between multiple first electrode tabs 211 and electrode terminals 30, reducing the risk of welding cracks in the first electrode tabs 211, and improving the current capacity of the electrode tabs after welding.

[0134] An embodiment of the present application provides a battery manufacturing apparatus 700, comprising a first providing assembly 710, a second providing assembly 740, a first welding assembly 720, and a second welding assembly 730. The first providing assembly 710 is configured to provide an electrode assembly 21 and an electrode terminal 30, wherein the electrode assembly comprises a plurality of first electrode tabs 211 stacked along a first direction X. The second providing assembly 740 is configured to provide a support gasket 60, which is stacked along the first direction X with the plurality of first electrode tabs 211. The first welding assembly 720 is configured to weld the support gasket 60 to the plurality of first electrode tabs 211 to form a first weld 40. The second welding assembly 730 is configured to weld the electrode terminal 60 to the plurality of first electrode tabs 211 and the support gasket 60 to form a second weld 50, wherein the projections of the first weld 40 and the second weld 50 on a plane perpendicular to the first direction X at least partially overlap.

[0135] The first providing assembly 710 is used to provide the electrode assembly 21 and the electrode terminal 30 . In some embodiments, the first providing assembly 710 may be a tray, a track, or a robotic arm device.

[0136] The second providing component 740 is used to provide the support pad 60. In some embodiments, the second providing component 740 can be a tray, a track, or a robotic arm device. The support pad 60 is a sheet-like structure. The material of the support pad 60 can be copper, a copper alloy, aluminum, or an aluminum alloy, etc., which is not limited in this embodiment.

[0137] The first welding assembly 720 may be a welding device, and the first welding assembly 720 may form the first weld 40 between the plurality of first electrode tabs 211 using heat, pressure, or a combination thereof. The first weld 40 may mechanically and electrically connect the plurality of first electrode tabs 211. In some embodiments, the first weld 40 may be formed by welding.

[0138] The second welding assembly 730 may be a welding device, and the second welding assembly 730 may form a second weld 50 between the first electrode tab 211 and the electrode terminal 30 by heat, pressure, or a combination thereof. The second weld 50 may mechanically and electrically connect the plurality of first electrode tabs 211 to the electrode terminal 30. In some embodiments, the second weld 50 may be formed by welding.

[0139] The projections of the first weld 40 and the second weld 50 on a plane perpendicular to the first direction X at least partially overlap, including cross-overlap and full overlap. In some embodiments, the projections of the first weld 40 and the second weld 50 on a plane perpendicular to the first direction X cross-overlap. In other embodiments, the full overlap of the projections of the first weld 40 and the second weld 50 includes: the projection of the first weld 40 on a plane perpendicular to the first direction X completely falls within the projection of the second weld 50, the projection of the second weld 50 on a plane perpendicular to the first direction X completely falls within the projection of the first weld 40, or the projections of the first weld 40 and the second weld 50 on a plane perpendicular to the first direction X completely overlap.

[0140] The first welds 40 formed between the plurality of first electrode tabs 211 enable electrical connection between the first electrode tabs 211, and the second welds 50 enable electrical connection between the plurality of electrode tabs and the electrode terminal 30. The connection between the plurality of first electrode tabs 211 and the support gasket 60 and the electrode terminal 60 via the at least partially overlapping first and second welds helps improve the reliability of the electrical connection between the plurality of first electrode tabs 211 and the electrode terminal 30, while also enhancing the current flow capacity between the first electrode tabs 211 and the electrode terminal 30.

[0141] According to some embodiments of the present application, the welding energy output by the first welding assembly 720 is less than the welding energy output by the second welding assembly 730. Welding energy refers to the heat input to a weld per unit length during the welding process.

[0142] The welding energy output by the first welding assembly 720 is less than the welding energy output by the second welding assembly 730 , which is beneficial to protecting the first electrode tab 211 , reducing the risk of cracks in the first electrode tab 211 , and improving the reliability of the welding connection.

[0143] According to some embodiments of the present application, the first welding assembly 720 is an ultrasonic welding assembly, and the second welding assembly 730 is a laser welding assembly.

[0144] Because the first tabs 211 are very thin sheets, insufficient welding energy during the connection of multiple first tabs 211 to the electrode terminals 30 may result in a cold weld. Excessive welding energy can easily cause cracks at the edges of the weld marks, thereby affecting the reliability of the tab connections. Therefore, based on material characteristics, the first welding assembly 720 may be an ultrasonic welding assembly to protect the first tabs 211, and the second welding assembly 730 may be a laser welding assembly to achieve a weld mark with higher connection strength and current capacity.

[0145] Selecting corresponding welding methods according to different welding objects is beneficial to improving the welding quality between multiple first electrode tabs 211 and between multiple first electrode tabs 211 and electrode terminals 30, reducing the risk of welding cracks in the first electrode tabs 211, and improving the current capacity of the electrode tabs after welding.

[0146] An embodiment of the present application provides a battery device, including the battery cell 20 of the aforementioned embodiment.

[0147] The first weld portion 40 and the second weld portion 50 of the battery cell 20 at least partially overlap in projection on a specific plane, which helps to improve the connection reliability between the tab and the connection terminal in the battery cell, thereby improving the safety and service life of the battery device.

[0148] An embodiment of the present application provides an electrical device, including the battery device of the aforementioned embodiment, and the battery device is used to provide electrical energy.

[0149] The electrical device may be, but is not limited to, a mobile phone, tablet, laptop computer, electric toy, electric tool, battery car, electric car, ship, spacecraft, etc. Among them, the electric toy may include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., and the spacecraft may include airplanes, rockets, space shuttles, and spacecraft, etc. The electrical device provided in the embodiment of the present application can achieve the same technical effect as the battery cell provided in the embodiment of the present application, and will not be repeated here.

[0150] like Figure 3-10 For example, the present application provides a battery cell 20 including an electrode assembly 21 , a support gasket 60 and an electrode terminal 30 .

[0151] The electrode assembly 21 includes a first electrode sheet and a second electrode sheet alternately stacked along a first direction X. The first electrode sheet includes a current collector and an active material layer located on at least one surface of the current collector. A portion of the current collector extends beyond the active material layer to form a first electrode tab 211. The first electrode sheet is a positive electrode sheet, and the second electrode sheet is a negative electrode sheet. The number of positive and negative electrode sheets is greater than one, and each layer is independent of the other. A first electrode tab 211 with a thickness ranging from 1 micron to 50 microns is provided on the end surface of the positive electrode sheet, and a electrode tab with a thickness ranging from 1 micron to 50 microns is provided on the end surface of the negative electrode sheet.

[0152] The positive electrode sheet can be made of a ternary material, such as lithium iron phosphate, with a sulfide, halide, oxide, or polymer solid electrolyte added. The negative electrode sheet can be coated with a silicon-carbon material, lithium metal without a negative electrode, stainless steel, hard carbon, or nanosilver. The first tabs are stacked in sequence to form a multi-layer copper tab body, while the tabs on the negative electrode end face are stacked in sequence to form a multi-layer aluminum tab body.

[0153] The electrode assembly 21 includes stacked first electrode sheets. The stacked first electrode sheets extend to form a plurality of first electrode tabs 211. The plurality of first electrode tabs 211 are ultrasonically welded to a support gasket 60 to form a first weld 40. Furthermore, the plurality of first electrode tabs 211, the support gasket 60, and the electrode terminal 30 are laser welded to form a second weld 50. The thickness of the support gasket 60 is greater than or equal to 0.2 mm and less than or equal to 0.5 mm. The projection of the second weld 50 onto a plane perpendicular to the first direction X completely falls within the projection of the first weld 40 onto the plane.

[0154] In some embodiments, along the first direction X, the plurality of first pole tabs 211 are located on one side of the support gasket 60 and the electrode terminal 30 is located on the other side of the support gasket 60. In other embodiments, along the first direction X, a portion of the plurality of first pole tabs 211 are located on a side of the support gasket 60 away from the electrode terminal 30, and another portion of the plurality of first pole tabs 211 are located on a side of the support gasket 60 facing the electrode terminal 30.

[0155] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, characterized in that: include: The electrode assembly comprises a plurality of first electrode tabs stacked along a first direction; as well as a support gasket, stacked with the plurality of first pole tabs along the first direction, the support gasket and the plurality of first pole tabs being connected via a first welding portion, and An electrode terminal, wherein the electrode terminal is connected to the plurality of first electrode tabs and the support gasket via a second welding portion; At least a portion of the first welding portion is melt-welded to the electrode terminal to form the second welding portion, and projections of the first welding portion and the second welding portion on a plane perpendicular to the first direction at least partially overlap.

2. The battery cell according to claim 1, characterized in that: A projection of the second weld portion on a plane perpendicular to the first direction completely falls within a projection range of the first weld portion on the plane.

3. The battery cell according to claim 1, characterized in that: The first welded portion is formed by a first welding method, and the second welded portion is formed by a second welding method; The welding energy of the first welding method is smaller than the welding energy of the second welding method.

4. The battery cell according to claim 3, characterized in that: The first welding method is ultrasonic welding, and the second welding method is laser welding.

5. The battery cell according to any one of claims 1 to 4, characterized in that: The plurality of first electrode tabs are located on one side of the support gasket, and the electrode terminal is located on the other side of the support gasket.

6. The battery cell according to any one of claims 1 to 4, characterized in that: A portion of the plurality of first electrode tabs is located on a side of the support pad away from the electrode terminal, and another portion of the plurality of first electrode tabs is located on a side of the support pad facing the electrode terminal.

7. The battery cell according to any one of claims 1 to 4, characterized in that: The thickness of the supporting gasket is greater than or equal to 0.2 mm and less than or equal to 0.5 mm.

8. The battery cell according to any one of claims 1 to 4, characterized in that: The electrode assembly includes a first electrode sheet and a second electrode sheet alternately stacked along the first direction; the first electrode sheet includes a current collector and an active material layer located on at least one side of the current collector, and a portion of the current collector protrudes beyond the active material layer to form the plurality of first electrode tabs.

9. A method for preparing a battery monomer, characterized in that: include: Providing an electrode assembly, the electrode assembly comprising a plurality of first electrode tabs stacked along a first direction; The method of welding the plurality of first electrode tabs to form a first fusion joint comprises: Providing a support gasket, wherein the support gasket is stacked with the plurality of first tabs along the first direction; Welding the plurality of first electrode tabs to the support pad to form the first welding portion; Providing electrode terminals; The electrode terminal is welded to the multiple first electrode tabs and the support gasket to form a second welding portion, at least a portion of the first welding portion is melt-welded to the electrode terminal to form the second welding portion, and the projections of the first welding portion and the second welding portion on a plane perpendicular to the first direction at least partially overlap.

10. The method for preparing a battery cell according to claim 9, characterized in that: The step of welding the plurality of first electrode tabs and the support pad to form the first welded portion comprises: Disposing all of the plurality of first electrode tabs on one side of the support pad and welding them to form the first welding portion; or A portion of the plurality of first electrode tabs is disposed on one side of the support gasket, and another portion of the plurality of first electrode tabs is disposed on the other side of the support gasket, and the first fusion portion is formed by welding.

11. The method for preparing a battery monomer according to claim 9 or 10, characterized in that: A projection of the second weld portion on a plane perpendicular to the first direction completely falls within a projection range of the first weld portion on the plane.

12. The method for preparing a battery monomer according to claim 9 or 10, characterized in that: The first welded portion is formed by a first welding method, and the second welded portion is formed by a second welding method; The welding energy of the first welding method is smaller than the welding energy of the second welding method.

13. The method for preparing a battery monomer according to claim 12, characterized in that: The first welding method is ultrasonic welding, and the second welding method is laser welding.

14. A battery manufacturing device, characterized in that: include: A first providing component configured to provide an electrode assembly and an electrode terminal, wherein the electrode assembly includes a plurality of first electrode tabs stacked along a first direction; A second providing component is configured to provide a supporting gasket, wherein the supporting gasket is stacked with the plurality of first tabs along the first direction; A first welding assembly is configured to weld the support pad and the plurality of first electrode tabs to form a first welded portion; The second welding assembly is configured to weld the electrode terminal with the plurality of first pole tabs and the support gasket to form a second welding portion, wherein at least a portion of the first welding portion is melt-welded with the electrode terminal to form the second welding portion, and the projections of the first welding portion and the second welding portion on a plane perpendicular to the first direction at least partially overlap.

15. The battery manufacturing equipment according to claim 14, characterized in that: The welding energy output by the first welding assembly is less than the welding energy output by the second welding assembly.

16. The battery manufacturing equipment according to claim 15, characterized in that: The first welding assembly is an ultrasonic welding assembly, and the second welding assembly is a laser welding assembly.

17. A battery device, characterized in that: The invention comprises a battery cell as claimed in any one of claims 1 to 8.

18. An electrical device, characterized in that: The electrical device comprises the battery device as claimed in claim 17, wherein the battery device is used to provide electrical energy.

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