Battery cell, manufacturing method and manufacturing system thereof, battery and power-consuming device

Abstract

The embodiments of the present application provide a battery cell, a manufacturing method and a manufacturing system thereof, a battery, and an electrical device. The battery cell includes: a housing including an electrode lead-out portion; an electrode assembly housed in the housing, wherein the electrode assembly is provided with a first tab at one end facing the electrode lead-out portion, the first tab being wound around the winding axis of the electrode assembly and including multiple tab layers, at least a portion of the multiple tab layers being welded to form a first weld. A portion of the multiple tab layers is welded to the electrode lead-out portion to form a second weld; in the tab layers connected to the first weld, at least one tab layer is not welded to the electrode lead-out portion. The present application can improve the current carrying capacity of the battery cell.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and more particularly, to a battery cell and a manufacturing method and system thereof, a battery, and an electrical device. Background Art

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

[0003] In the development of battery technology, how to improve the current capacity of battery cells is a technical problem that needs to be solved urgently. Summary of the Invention

[0004] The present application provides a battery cell and a manufacturing method and system thereof, a battery, and an electrical device, which can improve the current carrying capacity of the battery cell.

[0005] In a first aspect, an embodiment of the present application provides a battery cell, comprising:

[0006] a housing including an electrode lead-out portion;

[0007] An electrode assembly is housed in the housing, wherein the electrode assembly is provided with a first tab at one end facing the electrode lead portion, the first tab being wound around a winding axis of the electrode assembly and comprising a plurality of tab layers, at least portions of the plurality of tab layers being welded to form a first weld portion;

[0008] Part of the multiple-turn tab layer is welded to the electrode lead portion to form a second welding portion; and in the tab layer connected to the first welding portion, at least one turn of the tab layer is not welded to the electrode lead portion.

[0009] In the above scheme, the tab layers that are not welded to the electrode lead parts are welded to shorten the conductive path between the tab layers and the conductive path between the tab layers and the electrode lead parts, thereby reducing resistance, improving the uniformity of current density, reducing the risk of pole piece polarization, and improving the overcurrent capacity and charging efficiency of the battery cell.

[0010] In some embodiments, at least one ring of the tab layer is connected to the first welding portion and the second welding portion.

[0011] In the above scheme, the at least one circle of the tab layer can transmit the current collected by the first welding part to the second welding part, so as to shorten the conductive path between the first welding part and the second welding part, thereby reducing the resistance, improving the uniformity of the current density, reducing the risk of pole piece polarization, and improving the overcurrent capacity and charging efficiency of the battery cell.

[0012] In some embodiments, the first welding portion is directly connected to the second welding portion.

[0013] In the above solution, the current collected by the first welding portion can flow directly into the second welding portion, thereby further shortening the conductive path between the first welding portion and the second welding portion, reducing resistance, and improving the current capacity and charging efficiency of the battery cell.

[0014] In some embodiments, the second welding portion includes a first portion formed at the electrode lead portion and a second portion formed at the first tab. In a direction parallel to the winding axis, a size of the second portion is larger than a size of the first welding portion.

[0015] In the above scheme, the first welding portion has a smaller size to reduce the energy required for welding the first pole ear and reduce the risk of burning the electrode assembly; the above scheme makes the size of the second part larger than the size of the first welding portion to ensure the connection strength between the electrode lead portion and the first pole ear and reduce the risk of battery cell failure.

[0016] In some embodiments, in a direction parallel to the winding axis, a size of the first weld portion is 0.2 mm to 0.5 mm, and a size of the second portion is 0.5 mm to 1.5 mm.

[0017] In some embodiments, the total number of turns of the tab layer is N1, N2 turns of the tab layer are connected through the first welding portion, and the value of N2 / N1 is 0.5-0.95.

[0018] In the above scheme, the value of N2 / N1 is set to 0.5-0.95 to reduce resistance, increase overcurrent, and reduce the risk of burning the electrode assembly.

[0019] In some embodiments, the first welding portion includes a plurality of first sub-welding portions, and the plurality of first sub-welding portions are spaced apart along the circumference of the first tab.

[0020] The above solution can form the first welding portion by welding multiple times, thereby reducing the heat generated by a single welding and lowering the risk of the electrode assembly being burned by high temperature.

[0021] In some embodiments, the first sub-welding portion is in a straight line, V-shape, W-shape, or curved shape.

[0022] In some embodiments, the first welding portion is a helical structure disposed around the winding axis.

[0023] In some embodiments, a plurality of second welding portions are provided, the plurality of second welding portions are arranged at intervals, and at least two second welding portions are connected to different tab layers.

[0024] In the above scheme, multiple second welding parts can realize current transmission between the first pole tab and the electrode lead-out part, so as to reduce the difference in the conductive paths of different pole tab layers, improve the uniformity of current density, reduce the risk of pole piece polarization, and improve the overcurrent capacity and charging efficiency of the battery cell.

[0025] In some embodiments, the ends of the multi-turn tab layer facing the electrode lead portion are bent and gathered to reduce the gap between the ends. The ends are used for welding to form a first welding portion and a second welding portion.

[0026] In the above solution, the ends of the multiple-turn tab layers are bent and gathered to reduce the gap between the tab layers and reduce the risk of laser leakage during the welding process.

[0027] In some embodiments, the electrode lead includes a main body portion and a connecting portion. The connecting portion surrounds the main body portion and has a thickness less than that of the main body portion. The connecting portion is welded to the first electrode tab to form a second weld portion. The first weld portion at least partially overlaps the main body portion in a direction parallel to the winding axis.

[0028] In this solution, by reducing the thickness of the connecting portion, the energy required to weld the connecting portion to the first tab is reduced, thereby reducing the risk of burning the separator of the electrode assembly. This solution connects the first welding portion to the tab layer that overlaps the main body, shortening the conductive path of the tab layer, reducing resistance, and improving current carrying capacity.

[0029] In some embodiments, the electrode lead-out portion further includes a reinforcement portion that protrudes from a surface of the connecting portion facing away from the electrode assembly and is connected to the main body portion. A portion of the connecting portion not covered by the reinforcement portion is welded to the first electrode tab to form a second weld portion.

[0030] In the above solution, the reinforcement portion is provided to increase the strength of the electrode lead-out portion, reduce deformation of the electrode lead-out portion, and reduce the risk of cracking of the second welding portion.

[0031] In some embodiments, there are multiple reinforcing portions, and the multiple reinforcing portions are spaced apart along the circumference of the main body.

[0032] In the above solution, the multiple reinforcement parts can further increase the strength of the electrode lead-out part and make the strength of the electrode lead-out part more uniform.

[0033] In some embodiments, the housing includes a shell and an end cap, wherein the shell has an opening and the end cap covers the opening of the shell. The end cap serves as an electrode lead-out portion.

[0034] In the above solution, the end cap is used as the electrode lead-out portion, which can eliminate the traditional electrode terminal and thus simplify the structure of the battery cell. The above solution directly welds the end cap to the first tab, which can eliminate the traditional current collecting plate, thereby reducing costs and simplifying the assembly process.

[0035] In some embodiments, the battery cells are cylindrical battery cells.

[0036] In a second aspect, an embodiment of the present application provides a battery comprising a plurality of battery cells according to any one of the embodiments of the first aspect.

[0037] In a third aspect, an embodiment of the present application provides an electrical device, comprising the battery of the second aspect, the battery being used to provide electrical energy.

[0038] In a fourth aspect, an embodiment of the present application provides a method for manufacturing a battery cell, comprising:

[0039] An electrode assembly is provided, wherein a first tab is provided at one end of the electrode assembly, and the first tab is wound around a winding axis of the electrode assembly and includes a plurality of tab layers;

[0040] Welding at least a portion of the multiple turns of the tab layer to form a first weld;

[0041] Providing a housing and placing the electrode assembly in the housing, wherein the housing includes an electrode lead-out portion, and the first electrode tab is located at one end of the electrode assembly facing the electrode lead-out portion;

[0042] Welding a portion of the multi-turn tab layer to the electrode lead-out portion to form a second welded portion;

[0043] Among them, in the tab layer connected to the first welding portion, at least one circle of the tab layer is not welded to the electrode lead portion.

[0044] In a fifth aspect, an embodiment of the present application provides a battery cell manufacturing system, comprising:

[0045] A first providing device provides an electrode assembly, wherein the electrode assembly is provided with a first tab at one end, the first tab being wound around a winding axis of the electrode assembly and comprising a plurality of tab layers;

[0046] A first welding device is used to weld at least part of the multiple turns of the tab layer to form a first welded portion;

[0047] A second providing device is used to provide a housing and place the electrode assembly into the housing, wherein the housing includes an electrode lead-out portion, and the first electrode tab is located at an end of the electrode assembly facing the electrode lead-out portion;

[0048] A second welding device is used to weld a portion of the multi-turn tab layer to the electrode lead-out portion to form a second welded portion;

[0049] Among them, in the tab layer connected to the first welding portion, at least one circle of the tab layer is not welded to the electrode lead portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings without creative work.

[0051] Figure 1 A schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0052] Figure 2 An exploded schematic diagram of a battery provided in some embodiments of the present application;

[0053] Figure 3 for Figure 2 A schematic structural diagram of the battery module shown;

[0054] Figure 4 A schematic cross-sectional view of a battery cell provided in some embodiments of the present application;

[0055] Figure 5 for Figure 4 An enlarged schematic diagram of a battery cell at circle A is shown;

[0056] Figure 6 A schematic structural diagram of an electrode assembly of a battery cell provided in some embodiments of the present application;

[0057] Figure 7 A schematic top view of a battery cell provided in some embodiments of the present application;

[0058] Figure 8 A schematic structural diagram of an electrode assembly of a battery cell provided in some other embodiments of the present application;

[0059] Figure 9 A schematic flow chart of a method for manufacturing a battery cell according to some embodiments of the present application;

[0060] Figure 10 A schematic block diagram of a battery cell manufacturing system provided in some embodiments of the present application.

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

[0062] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0063] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0064] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0065] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0066] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0067] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0068] The term "multiple" used in this application refers to more than two (including two), and "multiple turns" refers to more than two turns (including two).

[0069] In the present application, battery cells may include lithium-ion secondary battery cells, lithium-ion primary battery cells, lithium-sulfur battery cells, sodium-lithium-ion battery cells, sodium-ion battery cells or magnesium-ion battery cells, etc., and the embodiments of the present application are not limited to this.

[0070] The battery referred to in the embodiments of this application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in this application may include a battery module or a battery pack. A battery generally includes a casing that encloses one or more battery cells. The casing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0071] A battery cell includes an electrode assembly and an electrolyte. The electrode assembly includes a positive electrode sheet, a negative electrode sheet, and a separator. The battery cell primarily relies on the movement of metal ions between the positive and negative electrode sheets to operate. The positive electrode sheet includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector. The positive current collector includes a positive current collector portion and a positive electrode tab connected to the positive current collector portion. The positive current collector portion is coated with the positive active material layer, while the positive electrode tab is not coated with the positive active material layer. Taking lithium-ion batteries as an example, the material of the positive current collector can be aluminum, and the positive active material layer includes a positive active material. The positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode sheet includes a negative current collector and a negative active material layer, which is coated on the surface of the current collector. The negative current collector includes a negative current collecting portion and a negative electrode tab connected to the negative current collecting portion. The negative current collecting portion is coated with the negative active material layer, while the negative tab is not coated with the negative active material layer. The negative current collector can be made of copper, and the negative active material layer includes a negative active material, which can be carbon or silicon, for example. The separator can be made of materials such as PP (polypropylene) or PE (polyethylene).

[0072] The battery cell also includes an outer casing, which is used to house the electrode assembly and electrolyte. The outer casing includes a shell and end caps connected to the shell. The shell and end caps form a cavity to accommodate the electrode assembly and electrolyte. The electrode assembly can be electrically connected to the end caps or to the electrode terminals provided on the end caps.

[0073] Electrode assemblies typically use tabs to input and output current. To improve the tab's current handling capacity, the inventors experimented with a wound tab structure. Wrapped tabs consist of multiple layers of tabs, connected end-to-end along the winding direction. Compared to tabs in related art, wound tabs offer a larger current handling area and greater high-current handling capability.

[0074] However, the inventors found that when the tab is connected to the electrode lead-out part of the shell, the tab layer that can be directly welded to the electrode lead-out part is relatively limited due to factors such as the shape and position of the electrode lead-out part. This results in a longer conductive path between the tab layer that is not welded to the electrode lead-out part and the electrode lead-out part, causing the resistance of the electrode assembly to be relatively large and the current density to be uneven, which incurs the risk of pole piece polarization and affects the overcurrent capacity and charging efficiency of the battery cell.

[0075] In view of this, an embodiment of the present application provides a technical solution by welding the tab layer that is not welded to the electrode lead-out part to shorten the conductive path between the tab layers and the conductive path between the tab layer and the electrode lead-out part, thereby reducing the resistance of the electrode assembly, improving the uniformity of the current density, reducing the risk of pole sheet polarization, and improving the overcurrent capacity and charging efficiency of the battery cell.

[0076] The technical solutions described in the embodiments of the present application are applicable to batteries and electrical devices using batteries.

[0077] Electrical devices may include vehicles, mobile phones, portable devices, laptop computers, ships, spacecraft, electric toys, and electric tools, etc. Vehicles may include fuel vehicles, gas vehicles, or new energy vehicles. New energy vehicles may include pure electric vehicles, hybrid vehicles, or extended-range vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0078] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device.

[0079] Figure 1 A schematic structural diagram of a vehicle provided for some embodiments of the present application.

[0080] like Figure 1 As shown, a battery 2 is provided inside the vehicle 1, and the battery 2 can be provided at the bottom, head, or tail of the vehicle 1. The battery 2 can be used to power the vehicle 1, for example, the battery 2 can be used as an operating power source for the vehicle 1.

[0081] The vehicle 1 may further include a controller 3 and a motor 4 . The controller 3 is used to control the battery 2 to supply power to the motor 4 , for example, to meet the power requirements of the vehicle 1 during startup, navigation, and driving.

[0082] In some embodiments of the present application, the battery 2 can not only serve as the operating power source of the vehicle 1, but also serve as the driving power source of the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0083] Figure 2 Schematic diagram of an explosion of a battery provided in some embodiments of the present application.

[0084] like Figure 2 As shown, the battery 2 includes a box 5 and a battery cell ( Figure 2 The battery cells are housed in the box body 5 .

[0085] The housing 5 is used to house battery cells and can have various structures. In some embodiments, the housing 5 can include a first housing portion 5a and a second housing portion 5b. The first housing portion 5a and the second housing portion 5b overlap each other, and the first housing portion 5a and the second housing portion 5b together define a storage space 5c for accommodating the battery cells. The second housing portion 5b can be a hollow structure with one end open. The first housing portion 5a is a plate-like structure, and the first housing portion 5a overlaps the open side of the second housing portion 5b to form the housing 5 with the storage space 5c. The first housing portion 5a and the second housing portion 5b can also be hollow structures with one end open. The open side of the first housing portion 5a overlaps the open side of the second housing portion 5b to form the housing 5 with the storage space 5c. Of course, the first housing portion 5a and the second housing portion 5b can have various shapes, such as a cylinder, a rectangular parallelepiped, etc.

[0086] In order to improve the sealing performance after the first box body 5a and the second box body 5b are connected, a sealing member, such as a sealant, a sealing ring, etc., may also be provided between the first box body 5a and the second box body 5b.

[0087] Assuming that the first box body portion 5a covers the top of the second box body portion 5b, the first box body portion 5a can also be called an upper box cover, and the second box body portion 5b can also be called a lower box body.

[0088] In battery 2, there can be one or more battery cells. If there are multiple battery cells, they can be connected in series, in parallel, or in a hybrid configuration. A hybrid configuration refers to a combination of series and parallel connections. Multiple battery cells can be directly connected in series, in parallel, or in a hybrid configuration, and then the entire battery module can be housed within housing 5. Alternatively, multiple battery cells can be first connected in series, in parallel, or in a hybrid configuration to form a battery module 6, and then multiple battery modules 6 can be connected in series, in parallel, or in a hybrid configuration to form a single unit housed within housing 5.

[0089] Figure 3 for Figure 2 The schematic diagram of the battery module is shown.

[0090] In some embodiments, as Figure 3 As shown, there are multiple battery cells 7, which are first connected in series, in parallel, or in mixed series to form a battery module 6. The multiple battery modules 6 are then connected in series, in parallel, or in mixed series to form a whole, which is accommodated in a box.

[0091] Multiple battery cells 7 in the battery module 6 can be electrically connected via a busbar component to achieve parallel, series, or mixed connection of multiple battery cells 7 in the battery module 6. There can be one or more busbar components, each of which is used to electrically connect at least two battery cells.

[0092] Figure 4 A schematic cross-sectional view of a battery cell provided in some embodiments of the present application; Figure 5 for Figure 4 An enlarged schematic diagram of a battery cell at circle A is shown; Figure 6 A schematic structural diagram of an electrode assembly of a battery cell provided in some embodiments of the present application; Figure 7 A schematic top view of a battery cell provided in some embodiments of the present application.

[0093] like Figures 4 to 7 As shown, an embodiment of the present application provides a battery cell 7, which includes: a housing 20 including an electrode lead portion 21; an electrode assembly 10 accommodated in the housing 20, wherein the electrode assembly 10 is provided with a first tab 11 at one end facing the electrode lead portion 21. The first tab 11 is wound around a winding axis X of the electrode assembly 10 and includes multiple tab layers 111. At least a portion of the multiple tab layers 111 is welded to form a first weld portion W1. A portion of the multiple tab layers 111 is welded to the electrode lead portion 21 to form a second weld portion W2. Among the tab layers 111 connected to the first weld portion W1, at least one tab layer 111 is not welded to the electrode lead portion 21.

[0094] The electrode assembly 10 includes a first electrode plate, a second electrode plate, and a separator, wherein the separator is used to separate the first electrode plate and the second electrode plate. The polarity of the first electrode plate and the second electrode plate are opposite. In other words, one of the first electrode plate and the second electrode plate is a positive electrode plate, and the other of the first electrode plate and the second electrode plate is a negative electrode plate.

[0095] The first pole piece, the second pole piece and the separator are all strip-shaped structures, and are wound together around a winding axis X to form a wound structure. The wound structure can be a cylindrical structure, a flat structure or a structure of other shapes.

[0096] The electrode assembly 10 includes a main body 12, a first electrode tab 11, and a second electrode tab 13. The first electrode tab 11 and the second electrode tab 13 protrude from the main body 12. The first electrode tab 11 is the portion of the first electrode sheet not coated with the active material layer, and the second electrode tab 13 is the portion of the second electrode sheet not coated with the active material layer. Accordingly, one of the first electrode tab 11 and the second electrode tab 13 is a positive polarity tab, and the other is a negative polarity tab.

[0097] The first electrode tab 11 and the second electrode tab 13 are respectively provided on both sides of the main body 12. In other words, the first electrode tab 11 and the second electrode tab 13 are respectively provided at both ends of the electrode assembly 10. Optionally, the first electrode tab 11 and the second electrode tab 13 are respectively provided at both ends of the electrode assembly 10 along a direction parallel to the winding axis X.

[0098] The first electrode tab 11 is wound around the winding axis X of the electrode assembly 10 and is generally cylindrical. The first electrode tab 11 includes a plurality of tab layers 111 arranged around the winding axis X. Exemplarily, the first electrode tab 11 includes N1 tab layers 111, where N1 is a positive integer greater than 1.

[0099] The first tab 11 has an inner end 11a and an outer end 11b along the winding direction Y. In this embodiment, the tab layers 111 are divided based on the inner end 11a of the first tab 11. The winding direction Y is perpendicular to the winding axis X.

[0100] Specifically, the inner end 11a of the first pole tab 11 is the head end of the first circle of the pole tab layer 111, and the tail end of the first circle of the pole tab layer 111 is aligned with the head end of the first circle of the pole tab layer 111 in the radial direction of the first pole tab 11, and the first circle of the pole tab layer 111 surrounds the winding axis X. Correspondingly, the tail end of the first circle of the pole tab layer 111 is the head end of the second circle of the pole tab layer 111, and so on. The N1 circle of the pole tab layer 111 is connected end to end along the winding direction Y. When dividing the pole tab layer 111, the head end of each circle of the pole tab layer 111 is aligned with the inner end 11a of the first pole tab 11 along the radial direction of the first pole tab 11. The radial direction of the first pole tab 11 is perpendicular to the winding axis X and passes through the winding axis X.

[0101] Exemplarily, the inner end 11 a and the outer end 11 b of the first electrode tab 11 are aligned in the radial direction of the first electrode tab 11 , so that each turn of the electrode tab layer 111 circles the winding axis X once.

[0102] Of course, alternatively, there is a portion at the tail of the first electrode tab 11, which surrounds the winding axis X for less than one circle. For example, the portion can surround the winding axis for 1 / 3, 1 / 2, 2 / 3 or 3 / 4 of a circle.

[0103] After the winding is completed, the first pole tab 11 is generally cylindrical, with a gap between two adjacent turns of the pole tab layer 111. The embodiment of the present application can process the first pole tab 11 to reduce the gap between the pole tab layers 111, so as to facilitate the connection of the first pole tab 11 with the electrode lead-out portion 21. For example, the embodiment of the present application can perform a flattening process on the first pole tab 11 so that the end area of ​​the first pole tab 11 away from the main body 12 is gathered and gathered together. The flattening process is to shape the end area of ​​the first pole tab 11 away from the main body 12 by a flattening device, so as to compact the end area of ​​the first pole tab 11 and form a dense end face, reduce the gap between the pole tab layers 111, and facilitate the welding of the first pole tab 11 with the electrode lead-out portion 21.

[0104] Optionally, the second electrode tab 13 is wound multiple times around the winding axis X of the electrode assembly 10, and the second electrode tab 13 includes multiple electrode tab layers. Exemplarily, the second electrode tab 13 is also flattened to reduce gaps between the electrode tab layers of the second electrode tab 13.

[0105] The housing 20 may have various structural forms. For example, the housing 20 may include a shell 22 and an end cap 23. The shell 22 is a hollow structure with an opening. The end cap 23 covers the opening of the shell 22 and forms a sealed connection to form a sealed space for accommodating the electrode assembly 10 and the electrolyte.

[0106] The shell 22 can be of various shapes, such as a cylinder, a rectangular parallelepiped, etc. The shape of the shell 22 can be determined according to the specific shape of the electrode assembly 10. For example, if the electrode assembly 10 has a cylindrical structure, a cylindrical shell can be selected; if the electrode assembly 10 has a rectangular parallelepiped structure, a rectangular parallelepiped shell can be selected. Of course, the end cap 23 can also have various structures, such as a plate-like structure, a hollow structure, etc. For example, the shell 22 has a cylindrical structure, the end cap 23 has a plate-like structure, and the end cap 23 covers the opening of the shell 22.

[0107] In some examples, the housing 20 includes a shell 22 and an end cap 23. The shell 22 is a hollow structure with an opening on one side, and the end cap 23 covers the opening of the shell 22. In other examples, the housing 20 includes a shell 22 and two end caps 23. The shell 22 is a hollow structure with openings on two opposite sides, and each end cap 23 covers a corresponding opening of the shell 22.

[0108] The end cap 23 can be directly connected to the housing 22 or connected to the housing 22 through other components. For example, the housing 20 further includes a fixing member 24, which is used to fix the end cap 23 to the housing 22. For example, the fixing member 24 surrounds the outside of the end cap 23 and clamps the edge of the end cap 23 to achieve the connection between the fixing member 24 and the end cap 23; the outer edge of the fixing member 24 is welded to the housing 22 to achieve the connection between the fixing member 24 and the housing 22.

[0109] The housing 20 further includes a sealing member 25 , which is used to seal the opening of the housing 22 to improve the sealing performance of the battery cell 7 . For example, the sealing member 25 may be clamped between the fixing member 24 and the end cover 23 .

[0110] The sealing member 25 may be made of PP (polypropylene), PE (polyethylene) or fluororubber. Optionally, the sealing member 25 is made of an insulating material, which can insulate and separate the end cap 23 and the housing 22.

[0111] In some examples, the end cap 23 is provided with an electrolyte injection hole that extends through the end cap 23 along its thickness. During the electrolyte injection process of the battery cell 7, the electrolyte enters the interior of the battery cell 7 through the electrolyte injection hole. The battery cell 7 also includes a sealing plate 26 connected to the end cap 23 and covering the electrolyte injection hole. The sealing plate is used to seal the electrolyte injection hole after the electrolyte injection process is completed.

[0112] The housing 20 includes an electrode lead-out portion 21, which is used to lead out the current in the electrode assembly 10 to output the electrical energy generated by the electrode assembly 10. The electrode lead-out portion 21 can be an end cap 23, a shell 22, or other parts of the housing 20. This embodiment is not limited to this, as long as it can lead out the current. For example, in some examples, the end cap 23 serves as the electrode lead-out portion 21 and is electrically connected to the electrode assembly 10. Alternatively, the housing 20 also includes an electrode terminal (not shown) provided on the end cap 23, and the electrode terminal serves as the electrode lead-out portion 21 and is electrically connected to the electrode assembly 10.

[0113] In the first electrode tab 11, N2 tab layers 111 are connected by welding to form a first weld W1. N2 is a positive integer, and 2≤N2≤N1. For example, after the first electrode tab 11 is flattened, a laser is irradiated on the end face of the first electrode tab 11 facing away from the main body 12. The laser welds the N2 tab layers 111 together to form the first weld W1.

[0114] The N2 tab layers 111 are connected via the first welding portion W1 , which can shorten the conductive path between the N2 tab layers 111 to achieve the purpose of reducing resistance.

[0115] The N2-turn tab layer 111 may be continuously disposed along the winding direction Y. Alternatively, in the N2-turn tab layer 111 , a portion of the tab layer 111 may be continuously disposed along the winding direction Y, and another portion of the tab layer 111 may be continuously disposed along the winding direction Y. Another tab layer 111 not connected to the first welding portion W1 may be disposed between the portion of the tab layer 111 and the other portion of the tab layer 111 .

[0116] In the first electrode tab 11, the M-circle tab layer 111 is welded to the electrode lead portion 21, forming a second weld W2. M is a positive integer, and 1 ≤ M < N1. For example, after the electrode assembly 10 is placed within the housing 20, a laser is applied to the outer surface of the electrode lead portion 21, welding a portion of the electrode lead portion 21 to the M-circle tab layer 111, forming the second weld W2.

[0117] In the M-circle tab layer 111, the current of each tab layer 111 can be transmitted to the electrode lead-out portion 21 through the second welding portion W2 without flowing through other tab layers 111. This can shorten the conductive path of the M-circle tab layer 111 and reduce resistance.

[0118] The N2-circle tab layer 111 and the M-circle tab layer 111 may intersect; in other words, a portion of the tab layer 111 is used to form both the first weld W1 and the second weld W2. Alternatively, the N2-circle tab layer 111 and the M-circle tab layer 111 may not intersect; in other words, the tab layer 111 used to form the first weld W1 is different from the tab layer 111 used to form the second weld W2.

[0119] In the N2-circle tab layer 111, the N3-circle tab layer 111 is not welded to the electrode lead portion 21. N3 is a positive integer, and 2≤N3≤N2.

[0120] The N3-ring tab layer 111 is not welded to the electrode lead-out portion 21. Therefore, the current on the N3-ring tab layer 111 needs to be transmitted to the electrode lead-out portion 21 through the tab layer 111 welded to the electrode lead-out portion 21. If the N3-ring tab layer 111 is not connected through the first welding portion W1, then, in the N3-ring tab layer 111, the current on the tab layer 111 far from the second welding portion W2 needs to flow through the tab layer 111 close to the second welding portion W2, which results in a longer conductive path and higher resistance. In this embodiment, by welding the N3-ring tab layer 111, the current can be transmitted directly through the first welding portion W1, thereby shortening the conductive path between the N3-ring tab layers 111 to achieve the purpose of reducing resistance.

[0121] The first welding portion W1 and the second welding portion W2 may be directly connected or indirectly connected via the tab layer 111 .

[0122] In the battery cell 7 of the present application, the tab layer 111 that is not welded to the electrode lead-out portion 21 is welded to shorten the conductive path between the tab layers 111 and the conductive path between the tab layer 111 and the electrode lead-out portion 21, thereby reducing resistance, improving the uniformity of current density, reducing the risk of pole piece polarization, and improving the overcurrent capacity and charging efficiency of the battery cell 7.

[0123] In some embodiments, the housing 20 includes a shell 22 and an end cap 23. The shell 22 has an opening, and the end cap 23 covers the opening of the shell 22. The end cap 23 is the electrode lead-out portion 21.

[0124] In this embodiment, the end cap 23 is used as the electrode lead-out portion 21 , which can omit the traditional electrode terminal, thereby simplifying the structure of the battery cell 7 .

[0125] In this embodiment, the end cap 23 is welded directly to the first electrode tab 11, eliminating the need for a conventional collector plate, thereby reducing costs and simplifying the assembly process. During welding, the laser acts on the outer surface of the end cap 23. This allows the housing 22 and end cap 23 to protect the electrode assembly 10 from the outside, reducing the risk of metal particles generated by welding being spattered onto the electrode assembly 10.

[0126] In some embodiments, the battery cell 7 is a cylindrical battery cell. Accordingly, the electrode assembly 10 is a cylindrical structure, and the housing 22 is a cylindrical hollow structure.

[0127] In some embodiments, at least one circle of the tab layer 111 is connected to the first welding portion W1 and the second welding portion W2 .

[0128] In this embodiment, the at least one circle of the tab layer 111 can transmit the current collected by the first welding portion W1 to the second welding portion W2, so as to shorten the conductive path between the first welding portion W1 and the second welding portion W2, thereby reducing the resistance, improving the uniformity of the current density, reducing the risk of pole piece polarization, and improving the overcurrent capacity and charging efficiency of the battery cell 7.

[0129] In some embodiments, the first welding portion W1 is directly connected to the second welding portion W2 .

[0130] During the assembly of the battery cell 7 , the first tab 11 of the electrode assembly 10 is first welded to form a first welding portion W1 , and then after the electrode assembly 10 is placed in the housing 20 , the electrode lead portion 21 and the first tab 11 are welded to form a second welding portion W2 .

[0131] When welding the electrode lead portion 21 and the first tab 11 , a portion of the first weld portion W1 melts and connects to the electrode lead portion 21 , thereby forming a second weld portion W2 that intersects with and directly connects to the first weld portion W1 .

[0132] In this embodiment, the first welding portion W1 is directly connected to the second welding portion W2 so that the current collected by the first welding portion W1 can flow directly into the second welding portion W2, thereby further shortening the conductive path between the first welding portion W1 and the second welding portion W2, reducing resistance, and improving the current flow capacity and charging efficiency of the battery cell 7.

[0133] In other embodiments, the first welding portion W1 and the second welding portion W2 may also be spaced apart in the circumferential direction of the first tab 11. For example, for a tab layer 111 connected to both the first welding portion W1 and the second welding portion W2, the portion of the tab layer 111 connected to the first welding portion W1 and the portion of the tab layer 111 connected to the second welding portion W2 are spaced apart in the circumferential direction of the first tab 11.

[0134] In some embodiments, the second weld portion W2 includes a first portion W21 formed on the electrode lead portion 21 and a second portion W22 formed on the first tab 11. In a direction parallel to the winding axis X, a dimension D1 of the second portion W22 is larger than a dimension D2 of the first weld portion W1.

[0135] Exemplarily, the thickness direction of the electrode lead portion 21 is parallel to the winding axis X.

[0136] In a direction parallel to the winding axis X, a distance between the second welding portion W2 and the main body portion 12 is smaller than a distance between the first welding portion W1 and the main body portion 12 .

[0137] During the welding process between the electrode lead portion 21 and the first tab 11, a portion of the electrode lead portion 21 undergoes processes such as melting and solidification to form a first portion W21, while the aforementioned M-turn tab layer 111 also undergoes processes such as melting and solidification to form a second portion W22. The first portion W21 and the second portion W22 form an atomically bonded whole, reducing the resistance between the first tab 11 and the electrode lead portion 21 and improving current handling capacity.

[0138] When welding the first tab 11, the laser directly acts on the first tab 11. Although the first tab 11 has been flattened, if the laser energy is too high, the laser may still pass through the tab layers 111 and burn the separator, posing a safety risk. Therefore, this embodiment generally uses a low-energy laser to weld the tab layers 111 of the first tab 11. Correspondingly, the dimension D2 of the first weld portion W1 is also relatively small.

[0139] The multiple turns of the tab layers 111 of the first tab 11 are integrally connected. Even if cracks develop in the first weld W1 due to its low strength, current can still be transmitted between the tab layers 111. In other words, the cracks have little impact on current transmission. Therefore, this embodiment has a lower strength requirement for the first weld W1, and the first weld W1 can have a relatively small size.

[0140] The second welding portion W2 needs to connect the electrode lead portion 21 and the first electrode tab 11. If the size D1 of the second portion W22 is equal to or smaller than the size D2 of the first welding portion W1, the strength of the second portion W22 is relatively low and it is prone to cracking, which will affect the current capacity of the battery cell 7 and even cause the battery cell 7 to fail.

[0141] In this embodiment, the first welding portion W1 has a smaller size to reduce the energy required for welding the first pole tab 11 and reduce the risk of burning the electrode assembly 10; in this embodiment, the size D1 of the second portion W22 is larger than the size D2 of the first welding portion W1 to ensure the connection strength between the electrode lead portion 21 and the first pole tab 11 and reduce the risk of failure of the battery cell 7.

[0142] In some embodiments, in a direction parallel to the winding axis X, a dimension D2 of the first weld portion W1 is 0.2 mm-0.5 mm, and a dimension D1 of the second portion W22 is 0.5 mm-1.5 mm.

[0143] The smaller the dimension D2 of the first weld portion W1, the lower the strength of the first weld portion W1, and the higher the risk of cracking and failure of the first weld portion W1. The larger the dimension D2 of the first weld portion W1, the greater the welding energy required, and the higher the risk of laser burns to the main body 12 of the electrode assembly 10. After experiments, the inventors set the dimension D2 of the first weld portion W1 to 0.2 mm to 0.5 mm, which can ensure that the energy required for welding the first tab 11 meets the requirements and maximize the strength of the first weld portion W1.

[0144] The smaller the dimension D1 of the second portion W22, the lower the connection strength between the electrode lead portion 21 and the first tab 11. The larger the dimension D1 of the second portion W22, the smaller the distance between the second portion W22 and the main body 12, and the higher the risk of burns to the main body 12 from the heat generated by welding. After experiments, the inventors set the dimension D1 of the second portion W22 to 0.5 mm to 1.5 mm to ensure the connection strength between the electrode lead portion 21 and the first tab 11 and reduce the risk of burns to the main body 12.

[0145] In some embodiments, the total number of turns of the tab layer 111 is N1, N2 turns of the tab layer 111 are connected via the first welding portion W1, and the value of N2 / N1 is 0.5-0.95.

[0146] The larger the value of N2 / N1, the more turns of the tab layer 111 connected to the first weld W1, and the lower the resistance of the electrode assembly 10. However, if the value of N2 / N1 is too large, the laser may irradiate outside the first tab 11 due to errors during welding, causing the risk of burning the main body 12 of the electrode assembly 10.

[0147] After experiments, the inventors set the value of N2 / N1 to 0.5-0.95 to reduce resistance, increase overcurrent, and reduce the risk of the electrode assembly 10 being burned.

[0148] In some embodiments, the value of N2 / N1 is 0.7-0.9.

[0149] In some embodiments, the outermost tab layer 111 and the innermost tab layer 111 are not welded to other tab layers 111 .

[0150] In some embodiments, the first welding portion W1 includes a plurality of first sub-welding portions W11 , and the plurality of first sub-welding portions W11 are spaced apart along the circumference of the first tab 11 .

[0151] In some examples, the tab layer 111 connected to one first sub-weld portion W11 and the tab layer 111 connected to another first sub-weld portion W11 may be the same tab layer 111; in another example, the tab layer 111 connected to one first sub-weld portion W11 and the tab layer 111 connected to another first sub-weld portion W11 may be different tab layers 111; in yet another example, the tab layer 111 connected to one first sub-weld portion W11 and the tab layer 111 connected to another first sub-weld portion W11 are partially identical, that is, a portion of the tab layer 111 is simultaneously connected to the one first sub-weld portion W11 and the other first sub-weld portion W11.

[0152] In this embodiment, the first welding portion W1 may be formed by multiple welding operations to reduce heat generation during a single welding operation and lower the risk of the electrode assembly 10 being burned by high temperature.

[0153] In some embodiments, the first sub-welding portion W11 is linear, V-shaped, W-shaped, or curved.

[0154] In some embodiments, a plurality of second welding portions W2 are provided, the plurality of second welding portions W2 are arranged at intervals, and at least two second welding portions W2 are connected to different tab layers 111 .

[0155] In this embodiment, multiple second welding portions W2 can realize current transmission between the first pole tab 11 and the electrode lead-out portion 21, so as to reduce the difference in the conductive paths of different pole tab layers 111, improve the uniformity of current density, reduce the risk of pole piece polarization, and improve the overcurrent capacity and charging efficiency of the battery cell 7.

[0156] In some embodiments, the ends of the multi-turn tab layer 111 facing the electrode lead portion 21 are bent and gathered to reduce the gap between the ends. The ends of the tab layer 111 are used for welding to form a first welding portion W1 and a second welding portion W2.

[0157] In this embodiment, the ends of the multiple-turn tab layers 111 are bent and gathered together to reduce the gaps between the tab layers 111 and reduce the risk of laser leakage during the welding process.

[0158] In some embodiments, the electrode lead portion 21 includes a main body portion 211 and a connecting portion 212. The connecting portion 212 surrounds the outside of the main body portion 211 and has a thickness less than that of the main body portion 211. The connecting portion 212 is welded to the first electrode tab 11 to form a second weld portion W2. The first weld portion W1 at least partially overlaps the main body portion 211 in a direction parallel to the winding axis X.

[0159] In this embodiment, the thickness of the connecting portion 212 is reduced to reduce the energy required for welding the connecting portion 212 and the first electrode tab 11 , thereby reducing the risk of the separator of the electrode assembly 10 being burned.

[0160] In a direction parallel to the winding axis X, a portion of the tab layer 111 overlaps the main body 211. However, due to the thickness of the main body 211, direct welding to the tab layer 111 is difficult, resulting in a longer conductive path in the tab layer 111 that overlaps the main body 211. In this embodiment, the first weld W1 is connected to the tab layer 111 that overlaps the main body 211, shortening the conductive path of the tab layer 111, reducing resistance, and improving current carrying capacity.

[0161] In some embodiments, the electrolyte injection hole is provided in the body portion 211 .

[0162] In some embodiments, the connecting portion 212 is an annular flat plate.

[0163] In some embodiments, the electrode lead portion 21 further includes a reinforcement portion 213, which protrudes from a surface of the connecting portion 212 facing away from the electrode assembly 10 and is connected to the main portion 211. The portion of the connecting portion 212 not covered by the reinforcement portion 213 is welded to the first electrode tab 11 to form a second weld portion W2.

[0164] In this embodiment, the reinforcing portion 213 is provided to increase the strength of the electrode lead-out portion 21 , reduce deformation of the electrode lead-out portion 21 , and lower the risk of cracking of the second welding portion W2 .

[0165] In one embodiment, there are multiple reinforcement portions 213 , and the multiple reinforcement portions 213 are spaced apart along the circumference of the main body 211 .

[0166] In this embodiment, the plurality of reinforcing portions 213 can further increase the strength of the electrode lead portion 21 and make the strength of the electrode lead portion 21 more uniform.

[0167] In some embodiments, transition slopes 213 a are provided at both ends of the reinforcement portion 213 along the circumference of the main body portion 211 , and the transition slopes 213 a are connected to the outer surface of the connecting portion 212 .

[0168] Figure 8 Schematic diagram of the structure of the electrode assembly of the battery cell provided in some other embodiments of the present application.

[0169] like Figure 8 As shown, in some embodiments, the first welding portion W1 is a spiral structure arranged around the winding axis.

[0170] Figure 9 A schematic flow chart of a method for manufacturing a battery cell provided in some embodiments of the present application.

[0171] like Figure 9 As shown, the manufacturing method of the battery cell of the embodiment of the present application includes:

[0172] S100, providing an electrode assembly, wherein the electrode assembly is provided with a first tab at one end, the first tab being wound around a winding axis of the electrode assembly and including a plurality of tab layers;

[0173] S200, welding at least a portion of the multiple-turn tab layer to form a first weld;

[0174] S300, providing a housing and placing an electrode assembly into the housing, wherein the housing includes an electrode lead portion, and the first electrode tab is located at one end of the electrode assembly facing the electrode lead portion;

[0175] S400, welding a portion of the multi-turn tab layer to the electrode lead portion to form a second welding portion;

[0176] Among them, in the tab layer connected to the first welding portion, at least one circle of the tab layer is not welded to the electrode lead portion.

[0177] It should be noted that the relevant structure of the battery cell manufactured by the above-mentioned method for manufacturing the battery cell can refer to the battery cells provided in the above-mentioned embodiments.

[0178] Figure 10 A schematic block diagram of a battery cell manufacturing system provided in some embodiments of the present application.

[0179] like Figure 10 As shown, the battery cell manufacturing system 90 of the embodiment of the present application includes:

[0180] A first providing device 91 provides an electrode assembly, wherein the electrode assembly has a first tab at one end, the first tab being wound around a winding axis of the electrode assembly and including a plurality of tab layers;

[0181] A first welding device 92 is used to weld at least part of the multiple turns of the tab layer to form a first welded portion;

[0182] A second providing device 93 is used to provide a housing and place the electrode assembly into the housing, wherein the housing includes an electrode lead portion, and the first electrode tab is located at an end of the electrode assembly facing the electrode lead portion;

[0183] A second welding device 94 is used to weld a portion of the multi-turn tab layer to the electrode lead portion to form a second welded portion;

[0184] Among them, in the tab layer connected to the first welding portion, at least one circle of the tab layer is not welded to the electrode lead portion.

[0185] The relevant structures of the battery cells manufactured by the above manufacturing system can refer to the battery cells provided in the above embodiments.

[0186] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0187] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery cell, comprising: a housing including an electrode lead-out portion; an electrode assembly housed in the housing, the electrode assembly having a first tab at one end facing the electrode lead-out portion, the first tab being wound around a winding axis of the electrode assembly and comprising a plurality of tab layers, at least portions of the plurality of tab layers being welded to form a first weld; Part of the multiple turns of the tab layer is welded to the electrode lead-out portion and forms a plurality of second welding portions, the plurality of second welding portions are arranged at intervals, and at least two of the second welding portions are connected to different tab layers; in the tab layer connected to the first welding portion, at least one turn of the tab layer is not welded to the electrode lead-out portion; the second welding portion includes a first portion formed on the electrode lead-out portion and a second portion formed on the first tab; in a direction parallel to the winding axis, the size of the second portion is larger than the size of the first welding portion, the size of the first welding portion is 0.2 mm-0.5 mm, and the size of the second portion is 0.5 mm-1.5 mm.

2. The battery cell according to claim 1, wherein: At least one circle of the tab layer is connected to the first welding portion and the second welding portion.

3. The battery cell according to claim 2, wherein: The first welding portion is directly connected to the second welding portion.

4. The battery cell according to claim 1, wherein: The total number of turns of the tab layer is N1, and N2 turns of the tab layer are connected through the first welding portion. The value of N2 / N1 is 0.5-0.95, and both N1 and N2 are positive integers greater than 1.

5. The battery cell according to claim 1, wherein The first welding portion includes a plurality of first sub-welding portions, and the plurality of first sub-welding portions are arranged at intervals along the circumferential direction of the first electrode tab.

6. The battery cell according to claim 5, wherein: The first sub-welding portion is linear, V-shaped or W-shaped.

7. The battery cell according to claim 1, wherein: The first welding portion is a spiral structure arranged around the winding axis.

8. The battery cell according to claim 1, wherein The ends of the multi-turn tab layers facing the electrode lead-out portion are bent and gathered to reduce the gap between the ends; The end portions are used for welding to form the first welding portion and the second welding portion.

9. The battery cell according to claim 1, wherein: The electrode lead-out portion includes a main body portion and a connecting portion, wherein the connecting portion surrounds the outside of the main body portion, and the thickness of the connecting portion is smaller than the thickness of the main body portion; The connecting portion is used to be welded to the first electrode tab to form the second welding portion; in a direction parallel to the winding axis, the first welding portion at least partially overlaps with the main body portion.

10. The battery cell according to claim 9, wherein: The electrode lead-out portion further includes a reinforcement portion, the reinforcement portion protruding from a surface of the connecting portion away from the electrode assembly and connected to the main body portion; A portion of the connecting portion not covered by the reinforcing portion is used for welding to the first electrode tab to form the second welding portion.

11. The battery cell according to claim 10, wherein: There are a plurality of reinforcing parts, and the plurality of reinforcing parts are arranged at intervals along the circumference of the main body.

12. The battery cell according to claim 1, wherein The housing includes a shell and an end cover, the shell has an opening, and the end cover covers the opening of the shell; The end cap is the electrode lead-out portion.

13. The battery cell according to any one of claims 1 to 12, wherein: The battery cell is a cylindrical battery cell.

14. A battery comprising a plurality of battery cells according to any one of claims 1 to 13.

15. An electrical device comprising the battery according to claim 14, wherein the battery is used to provide electrical energy.

16. A method for manufacturing a battery cell, comprising: An electrode assembly is provided, wherein the electrode assembly is provided with a first electrode tab at one end, the first electrode tab being wound around a winding axis of the electrode assembly and comprising a plurality of electrode tab layers; Welding at least a portion of the multiple-turn tab layer to form a first weld; Providing a housing and placing the electrode assembly into the housing, wherein the housing includes an electrode lead-out portion, and the first electrode tab is located at an end of the electrode assembly facing the electrode lead-out portion; Welding a portion of the multiple-turn tab layer to the electrode lead portion to form a plurality of second welding portions, wherein the plurality of second welding portions are arranged at intervals, and at least two of the second welding portions are connected to different tab layers; In which, in the tab layer connected to the first welding portion, at least one circle of the tab layer is not welded to the electrode lead-out portion; the second welding portion includes a first part formed on the electrode lead-out portion and a second part formed on the first tab; in a direction parallel to the winding axis, the size of the second part is larger than the size of the first welding portion, the size of the first welding portion is 0.2mm-0.5mm, and the size of the second part is 0.5mm-1.5mm.

17. A battery cell manufacturing system comprising: A first providing device provides an electrode assembly, wherein the electrode assembly is provided with a first tab at one end, the first tab being wound around a winding axis of the electrode assembly and comprising a plurality of tab layers; A first welding device is used to weld at least a portion of the multiple-turn tab layer to form a first welded portion; A second providing device is used to provide a housing and place the electrode assembly into the housing, wherein the housing includes an electrode lead-out portion, and the first electrode tab is located at an end of the electrode assembly facing the electrode lead-out portion; a second welding device for welding a portion of the multi-turn tab layer to the electrode lead-out portion to form a plurality of second welding portions, wherein the plurality of second welding portions are arranged at intervals, and at least two of the second welding portions are connected to different tab layers; In which, in the tab layer connected to the first welding portion, at least one circle of the tab layer is not welded to the electrode lead-out portion; the second welding portion includes a first part formed on the electrode lead-out portion and a second part formed on the first tab; in a direction parallel to the winding axis, the size of the second part is larger than the size of the first welding portion, the size of the first welding portion is 0.2mm-0.5mm, and the size of the second part is 0.5mm-1.5mm.

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