Battery cell, manufacturing method, manufacturing device, battery apparatus, and electric apparatus

Abstract

The present application relates to the technical field of batteries, and provides a battery cell, a manufacturing method, a manufacturing device, a battery apparatus, and an electric apparatus. The present application provides a battery cell. The battery cell comprises an electrode assembly, support spacers, and electrode terminals. The electrode assembly comprises a plurality of first tabs stacked in a first direction. The support spacers are stacked with the plurality of first tabs in the first direction, and the support spacers are connected to the plurality of first tabs by means of a first welding portion. The electrode terminals are connected to the plurality of first tabs and the support spacers by means of 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 of the tabs and the connection terminals can be improved, and the presence of the support spacers can provide support for the first tabs and improve the current-carrying capacity of the first tabs, thereby increasing the energy density of the battery.

Description

Battery cell, preparation method, manufacturing device, battery device and electric device

[0001] Cross-reference to related applications

[0002] This application is based on Chinese Patent Application No. 202411240752.5, filed on September 5, 2024, entitled "Battery cell, preparation method, manufacturing device, battery device and electric device", which is incorporated by reference in its entirety into this application. TECHNICAL FIELD

[0003] The present application relates to the technical field of battery, and in particular, to a battery cell, a preparation method, a manufacturing device, a battery device and an electric device. BACKGROUND

[0004] Energy saving and emission reduction is the key to the sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry due to their energy-saving and environmentally friendly advantages. For electric vehicles, battery technology is an important factor for their development.

[0005] In the manufacturing process of the battery, the welding of the tab of the battery cell is a very important process. The quality of the welding not only affects the reliability of the tab connection, but also affects the overcurrent capacity of the tab. SUMMARY

[0006] The present application aims to at least solve 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 electric device to improve the reliability of the tab connection of the battery.

[0007] An embodiment of the first aspect of the present application provides a battery cell. The battery cell includes an electrode assembly, a support pad and an electrode terminal. The electrode assembly includes a plurality of first tabs stacked along a first direction; the support pad is stacked along the first direction with the plurality of first tabs, and the support pad and the plurality of first tabs are connected by a first fusion portion; and the electrode terminal is connected with the plurality of first tabs and the support pad by a second fusion portion; wherein the projection of the first fusion portion and the second fusion portion in a plane perpendicular to the first direction at least partially overlaps.

[0008] The first welding part between the support pad and the plurality of first tabs can realize electrical connection between the plurality of first tabs, and the second welding part can realize electrical connection between the electrode terminal and the plurality of first tabs. The connection between the plurality of first tabs, the support pad and the electrode terminal through the first welding part and the second welding part that are at least partially overlapped can help improve the reliability of electrical connection between the plurality of tabs and the electrode terminal, and meanwhile, can improve the overcurrent capacity between the tabs and the electrode terminal. In addition, the support pad can be arranged to provide support for welding the first welding part for the plurality of first tabs, so as to reduce the probability of false welding and realize more reliable connection.

[0009] In some embodiments, a projection of the second welding part on a plane perpendicular to the first direction completely falls within a projection range of the first welding part on the plane. In this way, the force of the first tab on the edge of the first welding part can be reduced when the second welding part is formed, so as to reduce the risk of crack of the first tab and improve the reliability of connection between the first tab and the electrode terminal.

[0010] In some embodiments, the first welding part is formed by a first welding manner, and the second welding part is formed by a second welding manner; and the welding energy of the first welding manner is less than the welding energy of the second welding manner. The welding energy of the first welding manner is less than the welding energy of the second welding manner, which is conducive to protecting the first tab, reducing the risk of crack of the first tab and improving the reliability of welding connection.

[0011] In some embodiments, the first welding manner is ultrasonic welding, and the second welding manner is laser welding. Different welding manners are selected according to different welding objects, which is conducive to improving the welding quality between the plurality of first tabs and between the plurality of first tabs and the electrode terminal, reducing the risk of welding crack of the first tab and improving the overcurrent capacity of the tab after welding.

[0012] In some embodiments, the plurality of first tabs are located on one side of the support pad, and the electrode terminal is located on the other side of the support pad. In this way, the plurality of first tabs and the electrode terminal are respectively located on the two sides of the support pad, which is conducive to welding, so as to improve the welding efficiency of the first tab and the electrode terminal.

[0013] In some embodiments, a part of the plurality of first tabs is located on a side of the support pad away from the electrode terminal, and another part of the plurality of first tabs is located on a side of the support pad facing the electrode terminal. In this way, the contact area of the first tab and the support pad can be increased, the heat distribution can be more uniform, the welding quality can be higher, and the mechanical strength of the welding point and the stability of the electrical connection can be improved.

[0014] 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 support pad thickness is between 0.2 mm and 0.5 mm to better enable welding and improve weld quality, and to improve the reliability of the connection between the first tab and the electrode terminal.

[0015] In some embodiments, the electrode assembly includes first tabs and second tabs alternately arranged in a first direction; the first tab includes a current collector and an active material layer on at least one side surface of the current collector, and a portion of the current collector beyond the active material layer forms a first tab. By stacking the first tab and the second tab, and by connecting the first tab and the second tab to different electrode terminals, current transmission can be achieved.

[0016] Embodiments of the second aspect of the application provide a method for manufacturing a battery cell, the method comprising: providing an electrode assembly, the electrode assembly comprising a plurality of first tabs arranged in a first direction; welding the plurality of first tabs to form a first weld, comprising: providing a support pad, the support pad arranged in the first direction with the plurality of first tabs; welding the plurality of first tabs to the support pad to form the first weld; providing an electrode terminal; welding the electrode terminal to the plurality of first tabs and the support pad to form a second weld, a projection of the first weld and the second weld in a plane perpendicular to the first direction at least partially overlaps. The connection between the plurality of first tabs, the support pad, and the electrode terminal through the at least partially overlapping first weld and second weld helps to improve the reliability of the electrical connection between the plurality of first tabs and the electrode terminal, and to improve the efficiency of the welding.

[0017] In some embodiments, welding the plurality of first tabs to the support pad to form the first weld comprises: arranging all of the plurality of first tabs on one side of the support pad and welding to form the first weld; or arranging a portion of the plurality of first tabs on one side of the support pad and another portion of the plurality of first tabs on another side of the support pad, and welding to form the first weld. This can 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, thereby improving the welding efficiency of the first tab and the electrode terminal.

[0018] In some embodiments, the projection of the second weld in the plane perpendicular to the first direction falls completely within the projection range of the first weld in the plane. This can improve the current transfer capability 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.

[0019] In some embodiments, the first welding part is formed by a first welding manner, and the second welding part is formed by a second welding manner; and the welding energy of the first welding manner is less than the welding energy of the second welding manner. In this way, the first tab can be protected, and the reliability of the welding connection can be improved.

[0020] In some embodiments, the first welding manner is ultrasonic welding, and the second welding manner is laser welding. In this way, the welding quality between the plurality of first tabs and between the plurality of first tabs and the electrode terminal can be improved, the risk of welding cracks in the first tab can be reduced, and the overcurrent capacity of the first tab after welding can be improved.

[0021] Embodiments of the third aspect of the application provide a battery manufacturing device, which includes a first providing assembly, a second providing assembly, a first welding assembly, and a second welding assembly. The first providing assembly is configured to provide an electrode assembly and an electrode terminal, the electrode assembly including a plurality of first tabs stacked along a first direction; the second providing assembly is configured to provide a support pad, the support pad being stacked with the plurality of first tabs along the first direction; the first welding assembly is configured to weld the support pad and the plurality of first tabs to form a first welding part; and the second welding assembly is configured to weld the electrode terminal, the plurality of first tabs, and the support pad to form a second welding part, a projection of the first welding part and the second welding part on a plane perpendicular to the first direction at least partially overlaps. In this way, the reliability of the electrical connection between the plurality of first tabs and the electrode terminal can be improved, and the overcurrent capacity between the first tab and the electrode terminal can be improved.

[0022] In some embodiments, the welding energy output by the first welding assembly is less than the welding energy output by the second welding assembly. In this way, the first tab can be protected, the risk of cracks in the first tab can be reduced, and the reliability of the welding connection can be improved.

[0023] In some embodiments, the first welding assembly is an ultrasonic welding assembly, and the second welding assembly is a laser welding assembly. In this way, the welding quality between the plurality of first tabs and between the plurality of first tabs and the electrode terminal can be improved, the risk of welding cracks in the first tab can be reduced, and the overcurrent capacity of the first tab after welding can be improved.

[0024] Embodiments of the fourth aspect of the application provide a battery device, which includes the battery cell in the above embodiments.

[0025] Embodiments of the fifth aspect of the application provide a power consumption device, which includes the battery device in the above embodiments, and the battery device is configured to provide electrical energy.

[0026] The above description is only a summary of the technical solutions of the present application. In order to make the technical means of the present application more clearly understood and implemented according to the content of the specification, and in order to make the above and other purposes, characteristics and advantages of the present application more obvious and easy to understand, the following specific embodiments of the present application are described. BRIEF DESCRIPTION OF DRAWINGS

[0027] In the drawings, like reference numerals refer to same or similar components throughout the several views, unless otherwise indicated. These drawings are not necessarily to scale. It should be understood that these drawings only depict some embodiments in accordance with the disclosure and should not be considered limiting of the scope of the disclosure. In order to make the technical solutions of the embodiments of the present application more clearly understood, the drawings required to be used in the embodiments of the present application will be briefly introduced as follows. Obviously, the drawings described below are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the drawings.

[0028] FIG. 1 is a structural schematic diagram of a vehicle according to some embodiments of the present application;

[0029] FIG. 2 is an exploded structural schematic diagram of a battery according to some embodiments of the present application;

[0030] FIG. 3 is a structural schematic diagram of a battery cell according to some embodiments of the present application;

[0031] FIG. 4 is a structural schematic diagram of an electrode assembly according to some embodiments of the present application;

[0032] FIG. 5 is a structural schematic diagram of a battery cell according to some embodiments of the present application;

[0033] FIG. 6 is a partial enlarged view of FIG. 5;

[0034] FIG. 7 is a structural schematic diagram of a battery cell according to some embodiments of the present application;

[0035] FIG. 8 is a partial enlarged view of FIG. 7;

[0036] FIG. 9 is a flowchart of a method for manufacturing a battery cell according to some embodiments of the present application;

[0037] FIG. 10 is a structural block diagram of a battery manufacturing apparatus according to some embodiments of the present application.

[0038] Explanation of Reference Numerals: vehicle 1000; battery 100, controller 200, motor 300; case 10, first portion 11, second portion 12; battery cell 20, electrode assembly 21, first tab 211, case 22, end cap 23; electrode terminal 30, first fusion portion 40, second fusion portion 50, support gasket 60; battery manufacturing apparatus 700, first supply assembly 710, first welding assembly 720, second welding assembly 730, second supply assembly 740; first direction X. DETAILED DESCRIPTION

[0039] The embodiments of the technical solutions of the present application will be described in detail below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application; the terms "comprising" and "having," and any variations thereof, as used in the specification and claims and the aforementioned description of the drawings, are intended to cover not exclusively inclusive.

[0041] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0042] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearance of the phrase in various places in the specification does not necessarily all refer to the same embodiment, nor is it necessarily independent or alternative embodiments to each other. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0043] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " in this paper generally represents that the front and rear associated objects are a "or" relationship.

[0044] In the description of the embodiments of the present application, the term "a plurality of" refers to two or more (including two), and similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of pieces" refers to two or more pieces (including two pieces).

[0045] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the embodiments of the present application and simplifying the description, and does not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0046] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connection", "connection", "fixing" and the like should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrated; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0047] At present, from the development of market situation, the application of power battery is more and more extensive. Power battery is not only applied to energy storage power supply system of hydropower, thermal power, wind power and solar power station, but also widely used in electric bicycles, electric motorcycles, electric vehicles and other electric vehicles, as well as military equipment, aerospace and other fields. With the continuous expansion of the application field of power battery, the demand of its market is also increasing.

[0048] The tab is a metal conductor led out from the electrode tab of the electrode assembly, which is connected with the electrode terminal on the battery shell, and the current must flow through the tab and the electrode terminal to realize the connection with the outside of the battery. In the process of battery manufacturing, the tab and the electrode terminal can be connected by high temperature melting through welding method. Common welding methods include laser welding, ultrasonic welding and resistance hot melting welding.

[0049] Tab welding, as a key process in battery manufacturing, directly affects the performance and reliability of the battery. Because the thickness of the tab is thin, if the welding energy applied during welding with the pole is too high, cracks may occur on the tab, affecting the reliability of the connection between the tab and the pole, and the problem of insufficient flow of the tab during welding with the pole will also limit the energy density of the battery monomer.

[0050] Based on this, the application provides a battery monomer, which comprises an electrode assembly, a support pad and an electrode terminal. The electrode assembly comprises a plurality of first tabs stacked along a first direction; the support pad is stacked along the first direction with the plurality of first tabs, and the support pad is connected with the plurality of first tabs through a first fusion part; and the electrode terminal is connected with the plurality of first tabs and the support pad through a second fusion part; wherein the projection of the first fusion part and the second fusion part on a plane perpendicular to the first direction at least partially overlaps. The plurality of first tabs are connected with the support pad and the electrode terminal through the first fusion part and the second fusion part which at least partially overlap, so that the welding mark of the first fusion part can be directly used to improve the connection strength of the second fusion part, improve the connection reliability of the first tab and the connecting terminal, and the presence of the support pad can provide support for the first tab and improve the overcurrent capacity of the first tab, which is conducive to improving the energy density of the battery.

[0051] The battery monomer disclosed in the embodiments of the application can be used in, but is not limited to, an electric device such as a vehicle, a ship or an aircraft. The power supply system of the electric device can be composed of the battery monomer and the battery disclosed in the application.

[0052] The embodiments of the application provide an electric device using a battery as a power supply. The electric device can be, but is not limited to, a mobile phone, a tablet, a notebook computer, an electric toy, an electric tool, an electric vehicle, an electric car, a ship, a spacecraft and the like. The electric toy can include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy and an electric aircraft toy, and the spacecraft can include an airplane, a rocket, a space shuttle and a spacecraft.

[0053] The following embodiments are described with reference to a vehicle 1000 as an example of an electric device of an embodiment of the application for convenience of description.

[0054] Please refer to FIG. 1, which is a structural schematic diagram of a vehicle provided by some embodiments of the application. The vehicle 1000 can be a fuel automobile, a gas automobile or a new energy automobile, and the new energy automobile can be a pure electric automobile, a hybrid electric automobile or a range extended automobile. The vehicle 1000 is internally provided with a battery 100, which can be arranged at the bottom, the head or the tail of the vehicle 1000. The battery 100 can be used for power supply of the vehicle 1000, for example, the battery 100 can be used as an operating power supply of the vehicle 1000. The vehicle 1000 can further include a controller 200 and a motor 300, and the controller 200 is used to control the battery 100 to supply power to the motor 300, for example, to meet the working power demand of the vehicle 1000 during starting, navigation and driving.

[0055] In some embodiments of the present application, the battery 100 can not only serve as the operating power source of the vehicle 1000, but also serve as the driving power source of the vehicle 1000, replacing or partially replacing the fuel or natural gas to provide driving power for the vehicle 1000.

[0056] Please refer to FIG. 2, which is an exploded structural schematic diagram of a battery provided in some embodiments of the present application. The battery 100 includes a box body 10 and a battery monomer 20, and the battery monomer 20 is contained in the box body 10. The box body 10 is used to provide a containing space for the battery monomer 20, and the box body 10 can adopt various structures. In some embodiments, the box body 10 can include a first part 11 and a second part 12, and the first part 11 and the second part 12 are mutually covered. The first part 11 and the second part 12 jointly define a containing space for containing the battery monomer 20. The second part 12 can be a hollow structure with one end open, and the first part 11 can be a plate-shaped structure, which is covered on the open side of the second part 12 to jointly define the containing space with the second part 12. The first part 11 and the second part 12 can also be hollow structures with one side open, and the open side of the first part 11 is covered on the open side of the second part 12. Of course, the box body 10 formed by the first part 11 and the second part 12 can have various shapes, such as a cylinder, a cuboid, etc.

[0057] In the battery 100, the battery monomer 20 can be multiple, and the multiple battery monomers 20 can be connected in series, in parallel or in a mixed manner. The mixed manner means that the multiple battery monomers 20 are connected in series and in parallel. The multiple battery monomers 20 can be directly connected in series, in parallel or in a mixed manner, and then the whole of the multiple battery monomers 20 is contained in the box body 10. Of course, the battery 100 can also be that the multiple battery monomers 20 are first connected in series, in parallel or in a mixed manner to form a battery module, and then the multiple battery modules are connected in series, in parallel or in a mixed manner to form a whole, which is contained in the box body 10. The battery 100 can also include other structures, for example, the battery 100 can also include a current combing component for realizing the electrical connection between the multiple battery monomers 20.

[0058] Each battery monomer 20 can be a secondary battery or a primary battery, and can also be a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery, but is not limited thereto. The battery monomer 20 can be in the shape of a cylinder, a flat body, a cuboid or other shapes, etc.

[0059] As shown in the examples of FIGS. 3-10, FIG. 3 is a schematic structural diagram of a battery cell according to some embodiments of the present application; FIG. 4 is a schematic structural diagram of an electrode assembly according to some embodiments of the present application; FIG. 5 is a schematic structural diagram of a battery cell according to some embodiments of the present application; FIG. 6 is a partial enlarged view of FIG. 5; FIG. 7 is a schematic structural diagram of a battery cell according to some embodiments of the present application; FIG. 8 is a partial enlarged view of FIG. 7; FIG. 9 is a flowchart of a method for manufacturing a battery cell according to some embodiments of the present application; and FIG. 10 is a structural block diagram of a battery manufacturing apparatus according to some embodiments of the present application.

[0060] The battery cell 20 according to an embodiment of the present application includes an electrode assembly 21, a support pad 60, and an electrode terminal 30. The electrode assembly 21 includes a plurality of first tabs 211 stacked along a first direction X; the support pad 60 is stacked along the first direction X with the plurality of first tabs 211, and the support pad 60 is connected with the plurality of first tabs 211 through a first fusion portion 40; and the electrode terminal 30 is connected with the plurality of first tabs 211 and the support pad 60 through a second fusion portion 50; wherein a projection of the first fusion portion 40 and the second fusion portion 50 on a plane perpendicular to the first direction X at least partially overlaps.

[0061] As shown in FIG. 3, the electrode assembly 21 is a component where electrochemical reactions occur in the battery cell 20, and the electrode assembly 21 is arranged inside a housing 22 of the battery cell 20, which can contain one or more electrode assemblies 21. The electrode assembly 21 is mainly formed by winding or stacking a positive electrode sheet and a negative electrode sheet, and a separator is usually arranged between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet and the negative electrode sheet have portions with active materials constituting a main body of the electrode assembly, and portions without active materials of the positive electrode sheet and the negative electrode sheet each constitute a tab. The positive electrode tab and the negative electrode tab can be located together at one end of the main body or at two ends of the main body respectively. During the charging and discharging of the battery, the positive active material and the negative active material react with the electrolyte, and the tabs are connected to the electrode terminal to form a current loop. The first tab 211 can be a positive electrode tab or a negative electrode tab.

[0062] The first tab 211 can be a portion of foil material extending from a current collector of the electrode sheet, and the plurality of first tabs 211 extending from the wound electrode sheet are stacked along the first direction, which means that the plurality of foil materials extending from the wound layers as the first tabs are arranged in a stack along the first direction X, and the first direction is parallel to the thickness direction of the first tab 211.

[0063] The support pad 60 has a sheet structure, and the material of the support pad 60 can be a conductive metal, such as copper, copper alloy, aluminum, or aluminum alloy, etc., which is not limited in the present embodiment.

[0064] The electrode terminal 30 can be a post provided on the end cover 23. The end cover 23 is a component that cooperates with the case 22 to form an internal environment of the battery cell 20. The electrode terminal 30 can be used to electrically connect with the tabs of the electrode assembly 21 for outputting or inputting electric energy of the battery cell 20.

[0065] The first fusion portion 40 is a tight connection structure formed by heat, pressure, or a combination of both between the plurality of first tabs 211. The first fusion portion 40 can achieve mechanical connection and electrical connection of the plurality of first tabs 211. In some embodiments, the first fusion portion 40 can be formed by welding.

[0066] The second fusion portion 50 is a tight connection structure formed by heat, pressure, or a combination of both between the first tabs 211 and the electrode terminal 30. The second fusion portion 50 can achieve mechanical connection and electrical connection of the plurality of first tabs 211 and the electrode terminal 30. In some embodiments, the second fusion portion 50 can be formed by welding.

[0067] In some examples, in order to reduce the influence on each other, the first fusion portion 40 and the second fusion portion 50 on the support pad 60 are arranged staggered, but this will cause the current on the tab to flow through the support pad to achieve overcurrent, thereby limiting the overcurrent capacity of the tab. In the embodiments of the present application, the support pad 60 can be connected to the plurality of first tabs 211 through the first fusion portion 40, and connected to the electrode terminal 30 through the second fusion portion 50, and the first fusion portion 40 and the second fusion portion 50 at least partially overlap, so that the current on the first tab 211 can flow directly to the electrode terminal 30 through the first fusion portion 40 and the second fusion portion 50, and the presence of the support pad 60 can increase the size of the welding mark of the first fusion portion 40 and the second fusion portion 50, thereby solving the problem of insufficient overcurrent capacity of the tab welding, and since the current can flow from the first tab 211 to the electrode terminal 30, the size requirement of the support pad 60 can be reduced, thereby reducing the arrangement space of the support pad 60, thereby improving the energy density of the battery cell 20.

[0068] In some embodiments, the number of support pads 60 can be multiple, and the plurality of support pads 60 are arranged alternately with the first tabs in the first direction, thereby providing more uniform support and more sufficient overcurrent area for the plurality of first tabs 211. For example, the number of support pads 60 is only one less than the number of first tabs 211, and any one support pad is located between two adjacent first tabs 211.

[0069] The first welding portion 40 and the second welding portion 50 at least partially overlap in the projection of the plane perpendicular to the first direction X, including the cases of cross overlap and full overlap. In some embodiments, the first welding portion 40 and the second welding portion 50 have cross overlap in the projection of the plane perpendicular to the first direction X. In other embodiments, the cases of full overlap of the first welding portion 40 and the second welding portion 50 include: the projection of the first welding portion 40 in the plane perpendicular to the first direction X falls entirely into the projection of the second welding portion 50, the projection of the second welding portion 50 in the plane perpendicular to the first direction X falls entirely into the projection of the first welding portion 40, or the first welding portion 40 and the second welding portion 50 completely overlap in the projection of the plane perpendicular to the first direction X.

[0070] Since the first tab 211 is a very thin sheet in thickness, during the process of connecting the plurality of first tabs 211 with the electrode terminal 30, if the welding energy is insufficient, it can cause a virtual weld, and if the welding energy is too large, the edge position of the welding mark is prone to cracks, thereby affecting the reliability of the tab connection. In some embodiments, a part of the first welding portion 40 can be arranged in the welding area for forming the second welding portion 50, so that the first welding portion 40 which has been formed can be used to weld with the electrode terminal 30 to form the second welding portion 50. At this time, due to the presence of the support pad 60, the thickness of the first welding portion 40 is significantly increased compared to the thickness of a single first tab 211, and the possibility of cracks during welding is reduced, thereby achieving more reliable connection. On the other hand, the partial overlap of the first welding portion 40 and the second welding portion 50 actually means that at least a part of the first welding portion 40 is directly fused and connected with the electrode terminal 30, solving the problem of insufficient current flow caused by the narrow welding tab.

[0071] The first welding portion 40 formed between the plurality of first tabs 211 can achieve electrical connection between the first tabs 211, and the second welding portion 50 can achieve electrical connection between the plurality of tabs and the electrode terminal 30. The partial overlap of the first welding portion 40 and the second welding portion 50 in the projection of a specific plane helps to improve the reliability of the electrical connection between the plurality of first tabs 211 and the electrode terminal 30, and at the same time can improve the current carrying capacity between the first tab 211 and the electrode terminal 30.

[0072] According to some embodiments of the present application, the projection of the second welding portion 50 in the plane perpendicular to the first direction X falls entirely within the projection range of the first welding portion 40 in the plane.

[0073] In some embodiments, at least a part of the first welding portion 40 can be directly connected with the electrode terminal 30 to form the second welding portion 50, for example, at least a part of the first welding portion 40 is fused and welded with the electrode terminal 30 to form the second welding portion 50, so that the welding mark formed by the second welding portion 50 falls entirely into the projection range of the welding mark of the first welding portion 40.

[0074] The second welding portion 50 is projected to completely fall within the projection range of the first welding portion 40, so that the force acting on the first tab 211 at the edge of the first welding portion 40 can be reduced when the second welding portion 50 is formed, thereby reducing the risk of cracks in the first tab 211 and improving the reliability of the connection between the tab and the electrode terminal.

[0075] According to some embodiments of the present application, the first welding portion 40 is formed by a first welding method, and the second welding 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.

[0076] The first welding method is used to weld a plurality of first tabs 211 to form the first welding portion 40, and the second welding method is used to weld the plurality of first tabs 211 and the electrode terminal 30 to form the second welding portion 50. The first welding method can be the same welding form as the second welding method, or can be a different welding form.

[0077] Welding energy refers to the heat input to the weld joint per unit length during welding. Since the tab material is usually thin, a first welding method with lower welding energy can be used for welding. Since the thickness of the electrode terminal 30 (such as a pole) is relatively thick compared to the tab, the second welding portion 50 formed by the two needs to withstand higher strength connection and larger current, so the second welding method requires higher welding energy to meet the requirements.

[0078] For commonly used welding methods, such as ultrasonic welding and laser welding, the welding energy is calculated as follows: for ultrasonic welding, the welding energy generally refers to the energy applied to the welded joint per unit time during welding, and the calculation formula is: E = P x t;

[0079] wherein E represents the welding energy, the unit is joule (J); P represents the welding power, the unit is watt (W); t represents the welding time, the unit is second (s). In addition, the calculation formula of ultrasonic welding power is: P = 2p f A AT / d, wherein f is the ultrasonic frequency, A is the amplitude of the welding head, AT is the friction heat generated on the surface of the welding head, and d is the contact pressure between the welding head and the workpiece surface.

[0080] For laser welding, the welding energy is the total energy delivered to the welding material by the laser beam during welding, and the welding power is the energy delivered to the welding material by the laser beam per unit time during laser welding, which is usually expressed in watts (W). The calculation formula of the welding energy of laser welding is: E = P x t;

[0081] Wherein, E is the welding energy, unit is Joule (J); P is the laser welding power, which is the energy delivered by the laser beam to the welding material per unit time in the laser welding process, unit is Watt (W); t is the time required for welding, usually expressed in seconds (s).

[0082] In some embodiments, the plurality of first tabs 211 can be welded to form the first fusion portion 40 in a first welding manner with a lower welding energy, and then the first fusion portion 40 and the electrode terminal 30 are welded to form the second fusion portion 50 in a second welding manner with a higher welding energy.

[0083] The welding manner of the present embodiment is beneficial to protect the first tab 211, reduce the risk of crack of the first tab 211, and improve the reliability of the welding connection.

[0084] According to some embodiments of the present application, the first welding manner is ultrasonic welding, and the second welding manner is laser welding.

[0085] Ultrasonic welding is a method of welding using heat energy generated by high-frequency vibration. The ultrasonic energy is conducted to the contact surface of the workpiece to be welded, so that heat energy is generated due to friction to realize the connection of the material. This welding method is more suitable for welding between thin metals such as tabs, and can reduce the risk of crack.

[0086] Laser welding is a method of using high-energy laser beam as heat source to locally heat and melt the material to form a molten pool or keyhole, and realize the connection of the material. Laser welding is suitable for a variety of materials, including the connection between different metals. Laser welding has the advantages of high energy density, concentrated heating, fast welding speed, and small welding deformation. The second welding manner adopts laser welding to realize a higher connection strength and a welding print with higher current-carrying capacity.

[0087] According to the different welding objects, the corresponding welding manner is selected, which is beneficial to improve the welding quality between the plurality of first tabs 211 and between the plurality of first tabs 211 and the electrode terminal 30, reduce the risk of welding crack of the first tab 211, and improve the current-carrying capacity of the tab after welding.

[0088] Since the thickness of the first tab 211 is thin, by setting the support pad 60, support can be provided for the plurality of first tabs 211 to weld to form the first fusion portion 40 without affecting the current-carrying capacity, the probability of false welding is reduced, and more reliable connection is realized.

[0089] According to some embodiments of the present application, the plurality of first tabs 211 are located on one side of the support pad 60, and the electrode terminal 30 is located on the other side of the support pad 60.

[0090] As shown in the examples of FIG. 5 and FIG. 6, the plurality of first tabs 211 and the support pad 60 can be connected and fixed by ultrasonic welding in the first welding portion 40, and then the support pad 60 and the electrode terminal 30 are fixed and connected by laser welding in the second welding portion 50, wherein the projection of the first welding portion 40 and the second welding portion 50 on the plane perpendicular to the first direction X at least partially overlaps.

[0091] The plurality of first tabs 211 and the electrode terminal 30 are respectively arranged on both sides of the support pad 60, which is conducive to welding, thereby improving the welding efficiency of the first tabs 211 and the electrode terminal 30.

[0092] According to some embodiments of the present application, a part of the plurality of first tabs 211 is located on the side of the support pad 60 away from the electrode terminal 30, and another part of the plurality of first tabs 211 is located on the side of the support pad 60 facing the electrode terminal 30.

[0093] As shown in the examples of FIG. 7 and FIG. 8, a part of the plurality of first tabs 211, the support pad 60, another part of the plurality of first tabs 211 and the electrode terminal 30 are respectively placed along the first direction X, that is, the support pad 60 is connected and fixed to the middle position of the plurality of first tabs 211 by ultrasonic welding in the first welding portion 40, and then the support pad 60 and the electrode terminal 30 are fixed and connected by laser welding in the second welding portion 50, wherein the projection of the first welding portion 40 and the second welding portion 50 on the plane perpendicular to the first direction X at least partially overlaps.

[0094] The support pad 60 is welded to the middle position of the plurality of first tabs 211, which can increase the contact area of the first tabs 211 and the support pad 60, achieve more uniform heat distribution and higher welding quality, and improve the mechanical strength of the welding point and the stability of the electrical connection.

[0095] According to some embodiments of the present application, the thickness of the support pad 60 is greater than or equal to 0.2 millimeters and less than or equal to 0.5 millimeters.

[0096] The thickness of the support pad 60 is defined as the dimension along the first direction X. In some examples, the first tabs 211 and the electrode terminal 30 can be electrically connected by setting an adapter piece, at this time the adapter piece has an overcurrent capacity requirement, and usually needs to be designed to have a thickness of 0.6-0.8 millimeters, and sometimes even reaches 0.8 millimeters or more, which puts higher requirements on the arrangement space of the adapter piece, and too large thickness also leads to increased weight, which is not conducive to the energy density of the battery.

[0097] In this embodiment, the support pad 60 between the first tab 211 and the electrode terminal 30 is different from the commonly used adapter plate. The thickness of the support pad 60 can be designed to be thinner, for example, 0.2 mm, 0.3 mm, 0.4 mm or 0.5 mm, so as to improve the welding quality, the reliability of the tab connection and the overcurrent capacity of the tab.

[0098] According to some embodiments of the present application, the electrode assembly 21 comprises first and second tabs arranged alternately and stacked along the first direction X; the first tab comprises a current collector and an active material layer located on at least one side surface of the current collector, and a part of the current collector beyond the active material layer forms the first tab 211.

[0099] The first tab can be a positive tab or a negative tab, wherein in the electrode assembly 21, the positive and negative tabs are alternately stacked and arranged along the first direction X.

[0100] The current collector is one of the indispensable components in the battery, which not only can carry the active material, but also can collect and output the current generated by the electrode active material, which is beneficial to reduce the internal resistance of the lithium ion battery and improve the coulomb efficiency, cycle stability and rate performance of the battery. The active material is a substance that can participate in the flow reaction in the positive and negative electrodes of the battery. For the positive tab, the commonly used current collector is aluminum foil, and the thickness is generally between 10 microns and 20 microns. The aluminum foil is mainly rolled aluminum foil, which has good electrical conductivity and chemical stability. The active material of the commonly used positive tab includes but is not limited to the following: lithium cobaltate, lithium manganate, ternary material or lithium iron phosphate, etc. For the negative tab, the commonly used current collector is copper foil, and the thickness is generally between 6 microns and 8 microns. The copper foil is mainly electrolytic copper foil, which has high electrical conductivity and flexibility. The active material of the commonly used negative tab includes but is not limited to the following: graphite, silicon-based material or carbon nanomaterial. In some embodiments, the first tab 211 can be a part of the current collector of the positive tab or the current collector of the negative tab beyond the active material layer.

[0101] In some embodiments, a separator is further arranged between the stacked first and second tabs. The main function of the separator is to separate the positive and negative electrodes of the battery, while ensuring the passage of lithium ions, forming a charge and discharge circuit, and preventing the positive and negative electrodes from contacting to form a short circuit. The material of the separator is mainly polyolefin, such as polypropylene (PP) and polyethylene (PE) etc.

[0102] By stacking the first and second tabs and connecting the first and second tabs with different electrode terminals 30, current transmission can be achieved.

[0103] The embodiments of the second aspect of the present application provide a preparation method of a battery monomer, which comprises:

[0104] S101, provide an electrode assembly 21, the electrode assembly 21 includes a plurality of first tabs 211 arranged in a first direction X;

[0105] S102, a plurality of first tabs 211 are welded to form a first welding portion 40, comprising:

[0106] A support gasket 60 is provided, which is arranged in a first direction X with a plurality of first tabs 211;

[0107] A plurality of first tabs 211 and support gasket 60 are welded to form a first welding portion;

[0108] S103, provide an electrode terminal 30;

[0109] S104, the electrode terminal 30 is welded with a plurality of first tabs 211, support gasket 60 to form a second welding portion 50, the first welding portion 40 and the second welding portion 50 in the plane perpendicular to the first direction X projection at least partially overlap.

[0110] In step S101, the electrode assembly 21 can be a winding electrode core wound by stacking first and second polar plates with different polarities, or a laminated electrode core stacked by stacking first and second polar plates with different polarities. The current collector of the first polar plate extends to form a first tab, and a plurality of first tabs are arranged in a first direction X, wherein the first direction is parallel to the thickness of the first polar plate.

[0111] In step S102, the support gasket 60 is a sheet structure, which is a key component connecting the battery cover plate and the electrode core, and must meet the requirements of current overflow, strength and low spatter. The support gasket 60 is connected to a plurality of first tabs 211 and an electrode terminal 30 through a first welding portion 40 and a second welding portion 50, so that the current can be directly transferred from the first tab 211 to the electrode terminal 30 through the first welding portion 40 and the second welding portion 50.

[0112] In step S103, the electrode terminal 30 can be a pole provided on the end cover 23, one end of the electrode terminal 30 is connected with the tab, and the other end is connected with the outside, so as to realize the charging of the battery or the external discharge.

[0113] In step S104, the plurality of first tabs 211 and the electronic terminal are arranged in the first direction X and are fused together by welding to form a second fusion portion 50. The projections of the first fusion portion 40 and the second fusion portion 50 in a plane perpendicular to the first direction X at least partially overlap, including the cases of cross overlap and full overlap. In some embodiments, the projections of the first fusion portion 40 and the second fusion portion 50 in a plane perpendicular to the first direction X have cross overlap. In other embodiments, the cases of full overlap of the projections of the first fusion portion 40 and the second fusion portion 50 include: the projection of the first fusion portion 40 in a plane perpendicular to the first direction X falls entirely within the projection of the second fusion portion 50, the projection of the second fusion portion 50 in a plane perpendicular to the first direction X falls entirely within the projection of the first fusion portion 40, or the projections of the first fusion portion 40 and the second fusion portion 50 in a plane perpendicular to the first direction X completely overlap.

[0114] In some embodiments, a portion of the first fusion portion 40 can be disposed within a welding area used to form the second fusion portion 50, so that the second fusion portion 50 can be formed by welding the already formed first fusion portion 40 with the electrode terminal 30.

[0115] The formation of the first fusion portion 40 between the plurality of first tabs 211 can achieve electrical connection between the first tabs 211, and the second fusion portion 50 can achieve electrical connection between the plurality of tabs and the electrode terminal 30. The connection between the plurality of first tabs 211, the support pad 60, and the electrode terminal 60 through the first fusion portion and the second fusion portion that at least partially overlap helps to improve the reliability of the electrical connection between the plurality of first tabs 211 and the electrode terminal 30 and improve the welding fixation efficiency.

[0116] According to some embodiments of the present application, welding the plurality of first tabs 211 with the support pad 60 to form the first fusion portion 40 includes: disposing all of the plurality of first tabs 211 on one side of the support pad 60 and welding to form the first fusion portion 40; or disposing a portion of the plurality of first tabs 211 on one side of the support pad 60 and disposing another portion of the plurality of first tabs 211 on another side of the support pad 60, and welding to form the first fusion portion 40.

[0117] In some embodiments, the plurality of first tabs 211, the support pad 60, and the electrode terminal 30 are placed in the first direction X, respectively, the plurality of first tabs 211 and the support pad 60 can be connected and fixed by ultrasonic welding in the first fusion portion 40, and then the support pad 60 and the electrode terminal 30 are fixed and connected by laser welding to form the second fusion portion 50.

[0118] In some embodiments, the first welding method is ultrasonic welding, and the second welding method is laser welding.

[0119] In some embodiments, the plurality of tabs and the electrode terminal 30 are arranged on both sides of the support pad 60 or the support pad 60 is welded to the middle position of the plurality of first tabs 211, which can increase the contact area of the first tabs 211 and the support pad 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, and thus improve the welding efficiency of the first tabs 211 and the electrode terminal 30.

[0120] According to some methods for manufacturing a battery cell provided by the present application, the projection of the second welding portion 50 on the plane perpendicular to the first direction X completely falls within the projection range of the first welding portion 40 on the plane.

[0121] In some embodiments, at least a portion of the first welding portion 40 can be fusion welded with the electrode terminal 30 to form the second welding portion 50, so that the welding mark of the second welding portion 50 completely falls within the projection range of the welding mark of the first welding portion 40.

[0122] In the welding process, the projection of the second welding portion 50 completely falls within the projection range of the first welding portion 40, so that the force of the first tabs 211 on the edge of the first welding portion 40 can be reduced when the second welding portion 50 is formed, the transfer ability of the current to the first tabs 211 and the electrode terminal 30 is improved, the risk of cracks in the first tabs 211 is reduced, and the reliability of the connection between the tabs and the electrode terminal is improved.

[0123] According to some embodiments of the present application, the first welding portion 40 is formed by a first welding method, and the second welding 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.

[0124] In some embodiments, the plurality of first tabs 211 can be welded to form the first welding portion 40 by the first welding method with lower welding energy, and then the first welding portion 40 and the electrode terminal 30 can be welded to form the second welding portion 50 by the second welding method with higher welding energy.

[0125] By using different welding methods, the first tab 211 can be protected, the risk of cracks in the first tab 211 can be reduced, and the reliability of the welding connection can be improved.

[0126] According to some embodiments of the present application, the first welding method is ultrasonic welding, and the second welding method is laser welding.

[0127] Since the tab material is usually thin, the first welding method with lower welding energy can be used. Since the thickness of the electrode terminal 30 (for example, the pole) is relatively thick compared to the tab, the second fusion portion 50 formed by the two needs to withstand higher strength connection and larger current, and therefore the second welding method needs higher welding energy to meet the requirements. Therefore, the first welding method is set to ultrasonic welding, and the second welding method is set to laser welding.

[0128] According to the different welding objects, the corresponding welding methods are selected respectively, which is beneficial to improve the welding quality between the plurality of first tabs 211 and between the plurality of first tabs 211 and the electrode terminal 30, reduce the risk of welding cracks in the first tab 211, and improve the overcurrent capacity of the tab after welding.

[0129] The embodiments of the present application provide a battery manufacturing device 700, which includes 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, the electrode assembly including a plurality of first tabs 211 stacked along a first direction X; the second providing assembly 740 is configured to provide a support pad 60, the support pad 60 being stacked with the plurality of first tabs 211 along the first direction X; the first welding assembly 720 is configured to weld the support pad 60 and the plurality of first tabs 211 to form a first fusion portion 40; and the second welding assembly 730 is configured to weld the electrode terminal 60, the plurality of first tabs 211, and the support pad 60 to form a second fusion portion 50, and a projection of the first fusion portion 40 and the second fusion portion 50 in a plane perpendicular to the first direction X at least partially overlaps.

[0130] 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 can be a tray, a track, or a mechanical arm device.

[0131] The second providing assembly 740 is used to provide the support pad 60. In some embodiments, the second providing assembly 740 can be a tray, a track, or a mechanical arm device. The support pad 60 is a sheet structure, and the material of the support pad 60 can be copper, copper alloy, aluminum, or aluminum alloy, etc., which is not limited in the embodiments.

[0132] The first welding assembly 720 can be a welding device, and the first welding assembly 720 can form the first fusion portion 40 between the plurality of first tabs 211 by heat, pressure, or a combination thereof. The first fusion portion 40 can achieve mechanical and electrical connection between the plurality of first tabs 211. In some embodiments, the first fusion portion 40 can be formed by welding.

[0133] The second welding assembly 730 can be a welding device, and the second welding assembly 730 can form the second fusion portion 50 between the first tabs 211 and the electrode terminal 30 by heat, pressure, or a combination thereof. The second fusion portion 50 can achieve mechanical and electrical connection between the plurality of first tabs 211 and the electrode terminal 30. In some embodiments, the second fusion portion 50 can be formed by welding.

[0134] The projection of the first fusion portion 40 and the second fusion portion 50 in a plane perpendicular to the first direction X at least partially overlaps, including cross overlap and full overlap. In some embodiments, the projection of the first fusion portion 40 and the second fusion portion 50 in a plane perpendicular to the first direction X has cross overlap. In other embodiments, the projection of the first fusion portion 40 and the second fusion portion 50 fully overlaps, including: the projection of the first fusion portion 40 in a plane perpendicular to the first direction X falls entirely within the projection of the second fusion portion 50, the projection of the second fusion portion 50 in a plane perpendicular to the first direction X falls entirely within the projection of the first fusion portion 40, or the projection of the first fusion portion 40 and the second fusion portion 50 in a plane perpendicular to the first direction X fully overlaps.

[0135] The first fusion portion 40 formed between the plurality of first tabs 211 can achieve electrical connection between the plurality of first tabs 211, and the second fusion portion 50 can achieve electrical connection between the plurality of first tabs 211 and the electrode terminal 30. The connection between the plurality of first tabs 211, the support pad 60, and the electrode terminal 60 through the first fusion portion and the second fusion portion that at least partially overlaps can help improve the reliability of the electrical connection between the plurality of first tabs 211 and the electrode terminal 30, and can also improve the overcurrent capacity between the plurality of first tabs 211 and the electrode terminal 30.

[0136] 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. The welding energy refers to the heat input to the unit length of the weld during welding.

[0137] 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 protect the first tabs 211, reduce the risk of cracks in the first tabs 211, and improve the reliability of the welding connection.

[0138] 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.

[0139] Since the first tab 211 is a very thin sheet, if the welding energy is insufficient during the connection of the plurality of first tabs 211 and the electrode terminal 30, a false weld can be caused, and if the welding energy is too large, cracks can easily occur at the edge position of the welding mark, thereby affecting the reliability of the tab connection. Therefore, according to the material properties, the first welding assembly 720 can be an ultrasonic welding assembly to protect the first tab 211, and the second welding assembly 730 can be a laser welding assembly to achieve a higher connection strength and overcurrent capacity of the welding mark.

[0140] According to the different welding objects, the corresponding welding methods are selected respectively, which is beneficial to improve the welding quality between the plurality of first tabs 211 and between the plurality of first tabs 211 and the electrode terminal 30, reduce the risk of welding cracks of the first tab 211, and improve the overcurrent capacity of the tab after welding.

[0141] The embodiments of the present application provide a battery device, which includes the battery cell 20 of the foregoing embodiments.

[0142] The first fusion portion 40 and the second fusion portion 50 of the battery cell 20 at least partially overlap in a certain plane projection, which is beneficial to improve the connection reliability of the tab and the connection terminal in the battery cell, thereby improving the safety and service life of the battery device.

[0143] The embodiments of the present application provide a power consumption device, which includes the battery device of the foregoing embodiments, and the battery device is used to provide electric energy.

[0144] The power consumption device can be, but is not limited to, a mobile phone, a tablet, a notebook computer, an electric toy, an electric tool, an electric vehicle, an electric automobile, a ship, a spacecraft, etc. The electric toy can include a fixed or mobile electric toy, such as a game console, an electric automobile toy, an electric ship toy, an electric aircraft toy, etc. The spacecraft can include an airplane, a rocket, a space shuttle, a spacecraft, etc. The power consumption device provided by the embodiments of the present application can achieve the same technical effects as the battery cell provided by the embodiments of the present application, and thus the details are not described herein.

[0145] As shown in the examples of FIGS. 3-10, the battery cell 20 provided by the present application includes the electrode assembly 21, the support pad 60, and the electrode terminal 30.

[0146] The electrode assembly 21 includes first and second electrode sheets alternately and layerwisely arranged along the 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 beyond the active material layer forms a first tab 211. The first electrode sheet is a positive electrode sheet, and the second electrode sheet is a negative electrode sheet. The number of layers of the positive and negative electrode sheets is greater than 1, and each layer is independent of each other. The first tab 211 with a thickness ranging from 1 micrometer to 50 micrometers is arranged on the end surface of the positive electrode sheet, and the tab with a thickness ranging from 1 micrometer to 50 micrometers is arranged on the end surface of the negative electrode sheet.

[0147] The positive electrode sheet can be selected from a ternary material, such as a lithium iron phosphate material, and a sulfide, halide, oxide or polymer solid-state electrolyte. The coating material of the negative electrode sheet is a silicon-carbon material, a negative electrode-free lithium metal, a stainless steel material, a hard carbon material or a nano-silver material. The first tabs are sequentially and layerwisely arranged to form a multi-layer copper tab body, and the tabs on the end surface of the negative electrode sheet are sequentially and layerwisely arranged to form a multi-layer aluminum tab body.

[0148] The electrode assembly 21 includes layerwisely arranged first electrode sheets. A plurality of layerwisely arranged first electrode sheets extend to form a plurality of first tabs 211. The plurality of first tabs 211 and the support pad 60 are ultrasonically welded to form a first fusion portion 40. The plurality of first tabs 211 and the support pad 60 are laser welded to form a second fusion portion 50. The thickness of the support pad 60 is greater than or equal to 0.2 millimeters and less than or equal to 0.5 millimeters. The projection of the second fusion portion 50 on a plane perpendicular to the first direction X falls completely within the projection range of the first fusion portion 40 on the plane.

[0149] In some embodiments, the plurality of first tabs 211 are located on one side of the support pad 60 along the first direction X, and the electrode terminal 30 is located on the other side of the support pad 60. In other embodiments, a portion of the plurality of first tabs 211 are located on the side of the support pad 60 away from the electrode terminal 30 along the first direction X, and another portion of the plurality of first tabs 211 are located on the side of the support pad 60 facing the electrode terminal 30.

[0150] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than limit them. Although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that the technical solutions recorded in the foregoing embodiments can be modified, or some or all of the technical features can be replaced equivalently. Such modifications or replacements do not change the essence of the corresponding technical solutions, which should be covered in the scope of the claims and the specification of the present application. In particular, the technical features mentioned in each embodiment can be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, comprising: an electrode assembly comprising a plurality of first tabs stacked along a first direction; and a support pad stacked along the first direction with the plurality of first tabs, the support pad being connected with the plurality of first tabs by a first weld, and an electrode terminal connected with the plurality of first tabs, the support pad by a second weld; wherein a projection of the first weld and a projection of the second weld on a plane perpendicular to the first direction at least partially overlap. The projection of the second weld on the plane falls completely within the projection of the first weld on the plane.

2. The battery cell of claim 1, wherein, The first weld is formed by a first welding method, and the second weld is formed by a second welding method; 3. The battery cell of claim 1 or 2, wherein, wherein a welding energy of the first welding method is less than a welding energy of the second welding method. The first welding method is ultrasonic welding, and the second welding method is laser welding.

4. The battery cell of claim 3, wherein, The plurality of first tabs are located on one side of the support pad, and the electrode terminal is located on the other side of the support pad.

5. The battery cell of any one of claims 1-4, wherein, A portion of the plurality of first tabs are located on one side of the support pad away from the electrode terminal, and another portion of the plurality of first tabs are located on the other side of the support pad facing the electrode terminal.

6. The battery cell of any one of claims 1-4, wherein, The thickness of the support pad is greater than or equal to 0.2 mm and less than or equal to 0.5 mm.

7. The battery cell of any one of claims 1-6, wherein, The electrode assembly comprises first and second tabs alternately stacked along the first direction; the first tab comprises a current collector and an active material layer on at least one side surface of the current collector, and a portion of the current collector beyond the active material layer forms the plurality of first tabs.

8. The battery cell of any one of claims 1-7, wherein, 9.A method for manufacturing a battery cell, comprising: providing an electrode assembly comprising a plurality of first tabs stacked along a first direction; welding the plurality of first tabs to form a first weld, comprising: providing a support pad stacked along the first direction with the plurality of first tabs; welding the plurality of first tabs and the support pad to form the first weld; providing an electrode terminal; welding the electrode terminal with the plurality of first tabs and the support pad to form a second weld, the first weld and the second weld at least partially overlap on a plane perpendicular to the first direction. The welding the plurality of first tabs and the support pad to form the first weld comprises:

10. The method of claim 9, wherein the battery cell is a lithium-ion battery cell. arranging all of the plurality of first tabs on one side of the support pad and welding to form the first weld; or arranging a portion of the plurality of first tabs on one side of the support pad, and another portion of the plurality of first tabs on the other side of the support pad, and welding to form the first weld. The projection of the second weld on the plane falls completely within the projection of the first weld on the plane.

11. The method of producing a battery cell according to claim 9 or 10, wherein, The first weld is formed by a first welding method, and the second weld is formed by a second welding method; 12. The method of producing a battery cell according to any one of claims 9-11, wherein, ​ The first welding mode has a welding energy less than a welding energy of the second welding mode.

13. The method of claim 12, wherein the battery cell is a lithium-ion battery cell. The first welding mode is ultrasonic welding, and the second welding mode is laser welding.

14. A battery manufacturing apparatus comprising: a first providing assembly configured to provide an electrode assembly and an electrode terminal, the electrode assembly comprising a plurality of first tabs stacked along a first direction; a second providing assembly configured to provide a support pad stacked along the first direction with the plurality of first tabs; a first welding assembly configured to weld the support pad with the plurality of first tabs to form a first weld; a second welding assembly configured to weld the electrode terminal with the plurality of first tabs and the support pad to form a second weld, a projection of the first weld and the second weld on a plane perpendicular to the first direction at least partially overlap.

15. The battery manufacturing apparatus according to claim 14, wherein, The first welding assembly outputs a welding energy less than a welding energy output by the second welding assembly.

16. The battery manufacturing apparatus according to claim 14 or 15, wherein The first welding assembly is an ultrasonic welding assembly, and the second welding assembly is a laser welding assembly.

17. A battery device comprising the battery cell of any one of claims 1-8.

18. An electrical device comprising the battery device of claim 17, the battery device configured to provide electrical energy.

Images