CN117399776A

CN117399776A - Welding head, welding part, battery monomer, battery and power utilization device

Info

Publication number: CN117399776A
Application number: CN202311339373.7A
Authority: CN
Inventors: 吴凯; 白清林; 张正
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2023-10-17
Filing date: 2023-10-17
Publication date: 2024-01-16

Abstract

The application provides a welding head, a welding part, a battery monomer, a battery and an electric device. The welding member includes a first metal piece including a body portion and at least one welding region having opposing first and second surfaces that are convexly disposed toward a same side with respect to the body portion. The second metal piece is arranged on one side, close to the first surface, of the first metal piece, and comprises at least one welding part, and at least part of the welding part is attached to at least part of the first surface. The welding part that this application embodiment provided is favorable to increasing the effective welding area of welding head to first metalwork and second metalwork, and then is favorable to improving the welding reliability of first metalwork and second metalwork, is favorable to improving battery cell's overflow ability under the circumstances that welding part was applied to in the battery cell, and then is favorable to improving battery cell's reliability.

Description

Welding head, welding part, battery monomer, battery and power utilization device

Technical Field

The application relates to the technical field of batteries, in particular to a welding head, a welding part, a battery monomer, a battery and an electric device.

Background

Batteries are widely used in electronic devices such as cellular phones, notebook computers, battery cars, electric vehicles, electric airplanes, electric ships, electric toy vehicles, electric toy ships, electric toy airplanes, electric tools, and the like.

In the development of battery cell technology, in addition to improving the service performance of the battery cell, the reliability of the battery cell is also a problem to be considered. Therefore, how to improve the reliability of the battery cell is a continuous improvement in the battery cell technology.

Disclosure of Invention

The embodiment of the application provides a welding head, a welding part, a battery monomer, a battery and an electric device, and can improve the reliability of the battery monomer.

In a first aspect, embodiments of the present application provide a welded component comprising a first metal piece and a second metal piece, the first metal piece comprising a body portion and at least one weld region, the weld region having opposing first and second surfaces, the first and second surfaces being convexly disposed toward a same side relative to the body portion. The second metal piece is arranged on one side, close to the first surface, of the first metal piece, and comprises at least one welding part, and at least part of the welding part is attached to at least part of the first surface.

According to the welding component provided by the embodiment of the application, the first surface and the second surface of the welding area of the first metal piece are arranged towards the same side in a protruding mode relative to the body part, at least part of the welding part of the second metal piece is attached to at least part of the first surface, the shape of the welding head can be matched with the second surface in the ultrasonic welding process of the first metal piece and the second metal piece, so that the effective welding area of the welding head to the first metal piece and the second metal piece is increased on the premise that the radial size of the welding head is not increased, the welding reliability of the first metal piece and the second metal piece is improved, and the improvement of the overcurrent capacity of a battery monomer is facilitated under the condition that the welding component is applied to the battery monomer is facilitated, and the reliability of the battery monomer is improved.

In some embodiments, the first metal piece includes a plurality of weld areas, the plurality of weld areas being spaced apart; the second metal piece comprises a plurality of welding parts, and the welding parts are arranged in one-to-one correspondence with the welding areas. Therefore, the first metal piece and the second metal piece can be subjected to ultrasonic welding for a plurality of times, so that the effective welding area of the first metal piece and the effective welding area of the second metal piece are increased, the welding reliability of the first metal piece and the second metal piece is improved, and the overcurrent capacity of the battery is further improved under the condition that the welding part is applied to the battery cell.

In some embodiments, the first and second surfaces of the at least one weld region are convexly disposed in a direction away from the second metal piece, and the at least one weld includes a protrusion convexly disposed in a direction toward the first metal piece, at least a portion of the protrusion conforming to the first surface. At this time, the welding head can be arranged concave relative to the first metal piece so as to realize at least partial fitting of the welding head and the second surface, and thus, the effective welding area of the first metal piece and the second metal piece can be increased.

In some embodiments, the first and second surfaces of the at least one weld zone are convexly disposed toward the second metal piece, and the weld includes a recess recessed away from the first metal piece, at least a portion of the recess conforming to the first surface. At this time, the welding head can be arranged in a protruding manner relative to the first metal piece so as to realize at least partial fitting between the welding head and the second surface, and thus, the effective welding area of the first metal piece and the effective welding area of the second metal piece can be increased.

In some embodiments, the first metal piece is sheet-shaped and the weld area is formed by a stamping process. Therefore, the welding area is convenient for a craftsman to mold, the equal thickness of each part corresponding to the welding area is set, and after the welding of the first metal piece and the second metal piece is finished, the welding uniformity of the welding area and the welding part is improved, and the welding quality of the first metal piece and the second metal piece is improved.

In some embodiments, the welding region has at least one first recess disposed concave downward toward the second metal piece; the welding part is provided with at least one second concave part, the second concave part is concave away from the first metal piece, and the first concave part and the second concave part are mutually attached. The first concave part of the welding area of the first metal piece and the second concave part of the welding part of the second metal piece are mutually attached, in the welding process of the welding area and the welding part, the welding area and the welding part can be extruded and rubbed by the welding teeth of the welding head, plastic flow is generated between the welding area and the welding part conveniently, metal bonding is formed, and further the welding reliability of the first metal piece and the second metal piece is improved.

In some embodiments, the welding area is semi-ellipsoidal or truncated cone-shaped, and the welding area is arranged to protrude towards the second metal piece relative to the body portion, and the second metal piece points to the direction of the first metal piece, so that the cross section of the welding area tends to increase. Therefore, on the basis of increasing the effective welding area of the welding area and the welding part, the processing and forming of the welding area are facilitated. And under the condition that the welding area is arranged towards the second metal piece in a protruding way relative to the body part, the second metal piece points to the first metal piece, the section of the welding area is in an increasing trend, and the convenience of the welding head and the second surface in the fitting process of the welding head and the second surface is improved.

In some embodiments, the welding area is semi-ellipsoidal or truncated cone-shaped, and the welding area is arranged to protrude away from the second metal piece relative to the body portion, and the second metal piece points to the direction of the first metal piece, so that the cross section of the welding area is in a decreasing trend. Under the condition that the welding area is arranged opposite to the second metal piece in a protruding mode, the second metal piece points to the first metal piece, the section of the welding area is a reduced area, and convenience of the welding head and the second surface in cooperation is improved in the process of bonding the welding head and the second surface.

In some embodiments, the maximum dimension d of the orthographic projection of the second surface on the body portion satisfies: d is more than or equal to 30mm and less than or equal to 50mm.

In a second aspect, embodiments of the present application provide a battery cell including the welding component provided in any one of the embodiments above. On the premise of not increasing the radial dimension of the welding head, the contact area between the second surface and the welding head is favorably increased, and the effective welding area of the first metal piece and the second metal piece is favorably increased.

The battery monomer that this application provided owing to adopted the welding part that the arbitrary embodiment provided of above-mentioned, welding part's first metalwork and second metalwork have higher effective welding area, are favorable to improving first metalwork and second metalwork's welding reliability to be favorable to improving battery monomer's overflow ability, and then be favorable to improving battery monomer's reliability.

In some embodiments, the electrode terminal of the battery cell includes a second metal piece, and the current collector of the battery cell includes a first metal piece, the current collector electrically connecting the electrode terminal and the tab of the electrode assembly. By the arrangement, after the electrode terminal and the current collector are welded, the effective welding area of the electrode terminal and the current collector can be increased, the connection reliability of the electrode terminal and the current collector can be improved, the overcurrent capacity of the battery cell can be improved, and the reliability of the battery cell can be further improved.

In some embodiments, the electrode terminal of the battery cell includes a second metal piece, and the tab of the electrode assembly of the battery cell includes a first metal piece, and the tab is welded to the electrode terminal. Therefore, the connection reliability of the electrode lug and the electrode terminal is improved, the effective welding area of the electrode terminal and the electrode lug is improved, the overcurrent capacity of the battery cell is improved, and the reliability of the battery cell is further improved.

In a third aspect, embodiments of the present application provide a battery including the welded component provided in any of the embodiments described above or the battery cell provided in any of the embodiments described above.

The battery provided in the embodiment of the present application has the same technical effects due to the adoption of the welding component or the battery cell provided in any one of the embodiments, and is not described herein again.

In a fourth aspect, an embodiment of the present application provides an electrical device, including a battery provided in the foregoing embodiment, where the battery is configured to provide electrical energy.

The power utilization device provided by the embodiment of the present application has the same technical effects due to the battery provided by the above embodiment, and is not described herein again.

In a fifth aspect, embodiments of the present application provide a welding head, the welding head including a welding head body and a welding tooth, one end of the welding head body having a welding surface, the welding surface being arcuate and configured to cooperate with a second surface of a first metal piece of the welding component provided in any of the embodiments above to weld the welding region and the welding portion, the welding tooth being disposed on the welding surface.

The welding head that this embodiment provided has the welding surface through setting up the bonding tool body to set up the second surface looks adaptation of welding surface and the first metalwork of the welding part that any embodiment provided above, with adopt the welding head to carry out ultrasonic welding to the first metalwork and the second metalwork of the welding part that this embodiment provided, under the prerequisite that does not increase the radial dimension of welding head, be favorable to improving the effective welding area of first metalwork and second metalwork, when the welding part is applied to the battery monomer, be favorable to improving the free overflow ability of battery, and then improve the free reliability of battery.

In some embodiments, the bonding tool body has a protrusion or recess, and the bonding surface is an outer surface of the protrusion, or the bonding surface is an inner wall of the recess. The arrangement is convenient for realizing the matching of the welding surface and the second surface, and the welding head can smoothly carry out the welding work of the first metal piece and the second metal piece.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments of the present application will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present application, and that other drawings may be obtained according to the drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural view of a vehicle provided in an embodiment of the present application;

fig. 2 is a schematic structural view of a battery provided in an embodiment of the present application;

fig. 3 is a schematic structural view of a battery module in a battery according to an embodiment of the present disclosure;

fig. 4 is an exploded view of a battery cell according to an embodiment of the present disclosure;

fig. 5 is a schematic view of an exploded structure of another battery cell according to an embodiment of the present application;

FIG. 6 is a schematic structural view of a welded component provided in an embodiment of the present application;

FIG. 7 is a front view of a welded component provided in an embodiment of the present application;

FIG. 8 is a schematic cross-sectional view of FIG. 7 taken along line A-A;

FIG. 9 is a schematic cross-sectional view of a weld head provided in an embodiment of the present application;

FIG. 10 is a schematic view of another weld component provided in an embodiment of the present application;

FIG. 11 is a front view of another weld component provided by an embodiment of the present application;

FIG. 12 is a schematic cross-sectional view of the structure of FIG. 11 taken along B-B;

FIG. 13 is a schematic cross-sectional view of another weld head provided in an embodiment of the present application;

FIG. 14 is a schematic view of a still further weld assembly provided in accordance with an embodiment of the present application;

FIG. 15 is a front view of yet another weld component provided by an embodiment of the present application;

FIG. 16 is a schematic cross-sectional view of the structure of FIG. 15 taken along line C-C;

FIG. 17 is another cross-sectional structural schematic view taken along line C-C of FIG. 15;

FIG. 18 is a schematic view of a weld head provided in an embodiment of the present application;

fig. 19 is a schematic structural view of a battery cell according to an embodiment of the present disclosure;

FIG. 20 is a schematic cross-sectional view of the structure of FIG. 19 taken along D-D;

fig. 21 is a partial enlarged view at E in fig. 20.

In the drawings, the drawings are not necessarily to scale.

Marking:

1. a vehicle; 1a, a motor; 1b, a controller;

10. a battery; 11. a first box portion; 12. a second box portion; 13. a confluence member;

20. a battery module;

30. a battery cell;

31. a housing; 31a, a receiving cavity; 311. An end cap; 312. a housing;

32. an electrode assembly; 321. an electrode body; 322. a tab;

33. an electrode terminal;

34. a current collector;

40. welding parts; 41. a first metal piece; 411. a body portion; 412. a welding region; 412a, a first surface; 412b, a second surface; 4121. a first concave portion; 42. a second metal piece; 421. a welding part; 421a, a convex portion; 421b, grooves; 4211. a second concave portion;

50. a welding head; 51. a welding head body; 51a, a welding surface; 511. a protruding portion; 512. a recessed portion; 52. and welding teeth.

Detailed Description

Embodiments of the present application are described in further detail below with reference to the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are provided to illustrate the principles of the present application and are not intended to limit the scope of the application, i.e., the application is not limited to the embodiments described.

In the description of the present application, it is to be noted that, unless otherwise indicated, the meaning of "plurality" is two or more; the terms "upper," "lower," "left," "right," "inner," "outer," and the like indicate an orientation or positional relationship merely for convenience of description and to simplify the description, and do not indicate or imply that the devices or elements being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus are not to be construed as limiting the present application. Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. The "vertical" is not strictly vertical but is within the allowable error range. "parallel" is not strictly parallel but is within the tolerance of the error.

Reference in the specification to "an embodiment" means 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 appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly understand that the embodiments described herein may be combined with other embodiments.

In the description of the present application, it should also be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be directly connected or indirectly connected through an intermediate medium. The specific meaning of the terms in the present application can be understood as appropriate by one of ordinary skill in the art.

The term "plurality" as used herein refers to more than two (including two).

In the present application, the 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, and the embodiment of the present application is not limited thereto. The battery cells may be cylindrical, flat, rectangular, or otherwise shaped, as well as the embodiments herein are not limited in this regard.

The battery referred to in embodiments of the present application may include one or more battery cells to provide a single physical module of higher voltage and capacity. When a plurality of battery cells are provided, the plurality of battery cells are connected in series, in parallel or in series-parallel through the converging component.

In some embodiments, the battery may be a battery module; when a plurality of battery cells are provided, the plurality of battery cells are arranged and fixed to form a battery module.

In some embodiments, the battery may be a battery pack including a case and a battery cell, the battery cell or battery module being housed in the case.

In some embodiments, the tank may be part of the chassis structure of the vehicle. For example, a portion of the tank may become at least a portion of the floor of the vehicle, or a portion of the tank may become at least a portion of the cross member and the side member of the vehicle.

In some embodiments, the battery may be an energy storage device. The energy storage device comprises an energy storage container, an energy storage electric cabinet and the like.

The battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge of the battery cell, active ions (e.g., lithium ions) are inserted and extracted back and forth between the positive electrode and the negative electrode. The isolating film is arranged between the positive electrode and the negative electrode, can play a role in preventing the positive electrode and the negative electrode from being short-circuited, and can enable active ions to pass through.

In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

As an example, the positive electrode current collector has two surfaces opposing in its own thickness direction, and the positive electrode active material is provided on either or both of the two surfaces opposing the positive electrode current collector.

As an example, the positive electrode current collector may employ a metal foil or a composite current collector. For example, as the metal foil, silver-surface-treated stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, titanium, or the like can be used. The composite current collector may include a polymeric material base layer and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel alloy, titanium alloy, silver alloy, etc.) on a polymer material substrate (e.g., polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

As an example, the positive electrode active material may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. However, the present application is not limited to these materials, and other conventional materials that can be used as a battery positive electrode active material may be used. These positive electrode active materials may be used alone or in combination of two or more.

In some embodiments, the positive electrode may employ carbon foam or metal foam. The foam metal can be foam nickel, foam copper, foam aluminum or foam alloy. When the metal foam is used as the positive electrode, the surface of the metal foam may not be provided with the positive electrode active material, but may be provided with the positive electrode active material. As an example, a lithium source material, which is lithium metal and/or a lithium-rich material, potassium metal or sodium metal, may also be filled and/or deposited within the foam metal.

In some embodiments, the negative electrode may be a negative electrode tab, which may include a negative electrode current collector.

As an example, the negative electrode current collector may employ a metal foil or a composite current collector. For example, as the metal foil, silver surface treated stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, titanium, or the like can be used. The composite current collector may include a polymeric material base layer and a metal layer. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel alloy, titanium alloy, silver alloy, etc.) on a polymer material substrate (e.g., polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

As an example, the anode current collector has two surfaces opposing in its own thickness direction, and the anode active material is provided on either or both of the two surfaces opposing the anode current collector.

As an example, a negative active material for a battery cell, which is well known in the art, may be used. As an example, the anode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, and the like.

In some embodiments, the negative electrode may be carbon foam or metal foam. The foam metal can be foam nickel, foam copper, foam aluminum or foam alloy. When the foam metal is used as the negative electrode sheet, the surface of the foam metal does not need to be provided with a negative electrode active material, and the surface of the foam metal can be provided with the negative electrode active material.

As an example, a lithium source material, which is a lithium metal and/or a lithium-rich material, potassium metal, or sodium metal, may also be filled and/or deposited within the negative electrode current collector.

In some embodiments, the material of the positive electrode current collector may be aluminum and the material of the negative electrode current collector may be copper.

In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode. The type of the separator is not particularly limited, and any known porous separator having good chemical stability and mechanical stability may be used.

As an example, the main material of the separator may be at least one selected from glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic.

In some embodiments, the battery cell further includes an electrolyte that serves to conduct ions between the positive and negative electrodes. The type of electrolyte is not particularly limited in this application, and may be selected according to the need. The electrolyte may be liquid, gel or solid.

In some embodiments, the electrode assembly is a rolled structure. The positive plate and the negative plate are wound into a winding structure.

In some embodiments, the electrode assembly is a lamination stack.

The positive plate and the negative plate can be respectively arranged in a plurality, and the positive plates and the negative plates are alternately laminated.

As an example, a plurality of positive electrode sheets may be provided, and the negative electrode sheets are folded to form a plurality of folded sections arranged in a stacked manner, with one positive electrode sheet sandwiched between adjacent folded sections.

As an example, the positive and negative electrode sheets are each folded to form a plurality of folded sections in a stacked arrangement.

As an example, the separator may be provided in plurality, respectively between any adjacent positive electrode sheet or negative electrode sheet.

As an example, the separator may be continuously provided, being disposed between any adjacent positive or negative electrode sheets by folding or winding.

In some embodiments, the electrode assembly may have a cylindrical shape, a flat shape, a polygonal column shape, or the like.

In some embodiments, the electrode assembly is provided with tabs that can conduct current away from the electrode assembly. The tab includes a positive tab and a negative tab.

The battery cell further includes a case inside which a receiving chamber for receiving the electrode assembly is formed. The case may protect the electrode assembly from the outside to prevent foreign substances from affecting the charge or discharge of the electrode assembly.

In the related art, related metal parts inside the battery cell, such as an electrode terminal and a current collector of the battery cell or an electrode terminal and a tab of the battery cell, need to be welded and connected in an ultrasonic welding manner, so as to realize normal operation of the cycle operation of the battery cell. However, in the ultrasonic welding process, the diameter size of the welding head is limited, so that after the related metal parts are welded and connected, the effective welding area is smaller, and the improvement of the overcurrent capacity of the related metal parts is limited, so that the reliability of the battery cell is seriously affected.

In view of this, this embodiment provides a technical scheme, it is through setting up the at least partial laminating of the welded part of second metalwork and the welded area's of first metalwork first surface, in carrying out ultrasonic welding's in-process to first metalwork and second metalwork, can make the second surface butt of soldered connection and first metalwork, so, can increase the area of contact of soldered connection and first metalwork, be favorable to improving the effective welding area of first metalwork and second metalwork, and then be favorable to improving the overflow ability of first metalwork and second metalwork, when first metalwork and second metalwork are applied to the battery monomer, be favorable to improving the reliability of battery monomer.

The technical scheme described in the embodiments of the application is applicable to a welding head, a welding part, a battery cell comprising the welding part, a battery comprising the battery cell and an electric device using the battery.

The electric device may be a vehicle, a mobile phone, a portable device, a notebook computer, a ship, a spacecraft, an electric toy, an electric tool, or the like. The vehicle can be a fuel oil vehicle, a fuel gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle or a range-extended vehicle; spacecraft including airplanes, rockets, space planes, spacecraft, and the like; the electric toy includes fixed or mobile electric toys, such as a game machine, an electric car toy, an electric ship toy, and an electric airplane toy; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railroad power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete shakers, and electric planers, among others. The embodiment of the application does not limit the electric device in particular.

For convenience of explanation, the following examples will be described taking an electric device as an example of a vehicle.

As shown in fig. 1, a battery 10 is provided inside a vehicle 1. The battery 10 may be provided at the bottom or the head or the tail of the vehicle 1. The battery 10 may be used for power supply of the vehicle 1, for example, the battery 10 may serve as an operating power source of the vehicle 1.

The vehicle 1 may further include a controller 1b and a motor 1a. The controller 1b is used to control the battery 10 to supply power to the motor 1a, for example, for operating power requirements at start-up, navigation and travel of the vehicle 1.

In some embodiments of the present application, the battery 10 may not only serve as an operating power source for the vehicle 1, but also as a driving power source for the vehicle 1, providing driving power for the vehicle 1 instead of or in part instead of fuel oil or natural gas.

Referring to fig. 2, the battery 10 includes a battery cell 30. The battery 10 may further include a case for accommodating the battery cells 30.

The box is used for holding battery monomer, and the box can be multiple structural style. In some embodiments, the housing may include a first housing portion 11 and a second housing portion 12. The first housing part 11 and the second housing part 12 are mutually covered. The first and second casing parts 11 and 12 together define an accommodating space for accommodating the battery cells. The second case 12 may have a hollow structure with one end opened, the first case 11 has a plate-like structure, and the first case 11 is covered on the opening side of the second case 12 to form a case having an accommodation space; the first housing part 11 and the second housing part 12 may each have a hollow structure with one side opened. The open side of the first casing part 11 is closed to the open side of the second casing part 12 to form a casing having an accommodation space. Of course, the first and second case portions 11 and 12 may be of various shapes, such as a cylinder, a rectangular parallelepiped, or the like.

In order to improve the sealing property after the first casing part 11 and the second casing part 12 are connected, a sealing member, such as a sealant, a sealing ring, or the like, may be further provided between the first casing part 11 and the second casing part 12.

Assuming that the first housing part 11 is covered with the second housing part 12, the first housing part 11 may also be referred to as an upper case cover, and the second housing part 12 may also be referred to as a lower case.

In the battery 10, the number of battery cells may be one or more. If the number of the battery cells is multiple, the battery cells can be connected in series, in parallel or in series-parallel. The series-parallel connection refers to that a plurality of battery monomers are connected in series or in parallel. The plurality of battery cells can be directly connected in series or in parallel or in series-parallel, and then the whole formed by the plurality of battery cells is accommodated in the box body, or the plurality of battery cells can be connected in series or in parallel or in series-parallel to form the battery module 20. The plurality of battery modules 20 are then connected in series or parallel or a series-parallel combination to form a unit and are accommodated in a case.

In some embodiments, in the battery module 20, the battery cells are plural. The plurality of battery cells are first connected in series or parallel or a series-parallel combination to form the battery module 20. The plurality of battery modules 20 are then connected in series or parallel or a series-parallel combination to form a unit and are accommodated in a case.

In some embodiments, electrical connection between the plurality of battery cells in the battery module 20 may be achieved through a bus bar component to achieve parallel or series-parallel connection of the plurality of battery cells in the battery module 20.

Referring to fig. 4 and 5, a battery cell 30 provided in an embodiment of the present application includes an electrode assembly 32 and a housing 31, the housing 31 has a receiving cavity 31a, and the electrode assembly 32 is received in the receiving cavity 31 a.

The electrode assembly 32 may include an electrode body 321 and a tab 322, the tab 322 being drawn from an end of the electrode body 321.

In assembling the battery cell 30, the electrode assembly 32 may be placed in the receiving chamber 31a, the cap 311 is then capped on the case 312, and then an electrolyte is injected into the receiving chamber 31a through an electrolyte injection port formed in the cap 311.

In some embodiments, the housing 31 may also be used to contain an electrolyte, such as an electrolyte. The housing 31 may take a variety of structural forms.

The housing 31 may be of various shapes, such as a cylinder, a rectangular parallelepiped, etc. The shape of the case 31 may be determined according to the specific shape of the electrode assembly 32. For example, if the electrode assembly 32 has a cylindrical structure, the case 31 may alternatively have a cylindrical structure. If the electrode assembly 32 has a rectangular parallelepiped structure, the case 31 may alternatively have a rectangular parallelepiped structure. In fig. 4, the case 31 and the electrode assembly 32 are each of a cylindrical structure, and in fig. 5, the case 31 and the electrode assembly 32 are each of a rectangular parallelepiped structure, as an example.

The material of the housing 31 may be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc., which is not particularly limited in the embodiment of the present application.

The electrode assembly 32 accommodated in the case 31 may be one or more. In fig. 4, the number of electrode assemblies 32 accommodated in the case 31 is two.

As shown in fig. 3 to 9, the welding member 40 provided according to the embodiment of the present application includes a first metal piece 41 and a second metal piece 42, the first metal piece 41 includes a body portion 411 and at least one welding region 412, the welding region 412 has opposite first and second surfaces 412a and 412b, and the first and second surfaces 412a and 412b are convexly disposed toward the same side with respect to the body portion 411. The second metal piece 42 is disposed on a side of the first metal piece 41 near the first surface 412a, and the second metal piece 42 includes at least one welding portion 421, where at least a portion of the welding portion 421 is attached to at least a portion of the first surface 412 a.

The materials of the first and second metal pieces 41 and 42 may include copper, aluminum, iron, or the like, respectively.

The first metal piece 41 and the second metal piece 42 may be components within the battery cell 30, respectively, and illustratively, the first metal piece 41 is at least part of the current collecting piece 34 of the battery cell 30, the second metal piece 42 is at least part of the electrode terminal 33 of the battery cell 30, the first metal piece 41 and the second metal piece 42 are welded, and the first metal piece 41 and the second metal piece 42 are electrically connected, so that the electrical connection between the electrode terminal 33 and the tab 322 may be achieved; alternatively, the first metal member 41 is at least part of the electrode terminal 33 of the battery cell 30, the second metal member 42 is at least part of the tab 322 of the battery cell 30, and the first metal member 41 and the second metal member 42 are welded to each other, so that the battery cell 30 and the tab 322 are electrically connected.

Of course, it is also possible to provide the first metal member 41 as at least part of the electrode terminal 33 and the second metal member 42 as at least part of the bus bar 13, and the first metal member 41 and the second metal member 42 are welded to each other to electrically connect the electrode terminal 33 and the bus bar 13, and to connect a plurality of battery cells 30 in series or in parallel through the bus bar 13.

It should be noted that, in the description of the present application, the "at least one" may be one, a plurality of or all, and may be specifically selected according to actual needs. Correspondingly, the first metal piece 41 includes at least one welding area 412, so that the first metal piece 41 may have only one welding area 412, or may have a plurality of welding areas 412, and the plurality of welding areas 412 may be arranged in a regular manner, such as a circular array arrangement or a rectangular array arrangement; of course, the plurality of welding areas 412 may be arranged in an irregular manner.

The welding region 412 has a first surface 412a and a second surface 412b opposite to each other, and the first surface 412a and the second surface 412b are disposed to protrude toward the same side with respect to the body portion 411, so that the first surface 412a and the second surface 412b may be disposed opposite to each other in the thickness direction of the first metal piece 41 and located on both side surfaces of the first metal piece 41 in the thickness direction. Alternatively, the first metal piece 41 may have a block shape, and the first surface 412a and the second surface 412b may be located at two sides of the welding direction of the first metal piece 41 and the second metal piece 42, respectively.

Alternatively, the first surface 412a and the second surface 412b may be respectively provided in a convex arc shape or a tapered shape, and the first surface 412a and the second surface 412b may be parallel to each other, i.e. the first surface 412a and the second surface 412b are provided at equal intervals, or the corresponding intervals between different positions of the first surface 412a and the second surface 412b are different.

The welding region 412 of the first metal member 41 may be formed by using a stamping process such that the first surface 412a and the second surface 412b are parallel to each other. Alternatively, the weld area 412 is formed by removing material.

The second metal piece 42 is disposed on a side of the first metal piece 41 near the first surface 412a, and the first surface 412a and the second surface 412b may be disposed to protrude toward the second metal piece 42 at the same time, or the first surface 412a and the second surface 412b may be disposed to protrude along a direction opposite to the second metal piece 42 at the same time.

Since at least part of the welding portion 421 of the second metal member 42 is attached to at least part of the first surface 412a, in the case where the first surface 412a and the second surface 412b are simultaneously provided to protrude toward the second metal member 42, the welding portion 421 of the second metal member 42 is provided to be recessed in a direction away from the first metal member 41 so as to be attached to at least part of the first surface 412 a; in the case where the first surface 412a and the second surface 412b are simultaneously protruded in a direction away from the second metal member 42, the welding portion 421 of the second metal member 42 is protruded toward the first metal member 41 so as to be at least partially adhered to the first surface 412 a.

In this way, in the process of performing ultrasonic welding on the first metal piece 41 and the second metal piece 42, the side of the first metal piece 41 away from the second metal piece 42 may be welded, and the welding head 50 may be attached to at least a portion of the second surface 412b of the first metal piece 41, so as to achieve welding on the welding region 412 of the first metal piece 41 and the welding portion 421 of the second metal piece 42.

Since the second surface 412b is disposed to protrude from the body 411, the second surface 412b is arc-shaped or polyhedral, so that the welding head 50 and the second surface 412b can be adapted by providing an appropriate shape of the welding head 50, for example, the welding head 50 shown in fig. 9 can be used to weld the first metal piece 41 and the second metal piece 42 shown in fig. 8, and the contact area between the welding head 50 and the second surface 412b is increased without increasing the radial size of the welding head 50, which is beneficial to increasing the effective welding area of the first metal piece 41 and the second metal piece 42, further improving the welding reliability of the first metal piece 41 and the second metal piece 42, and improving the current flowing capability of the battery cell 30 and providing the reliability of the battery cell 30 when the first metal piece 41 and the second metal piece 42 are applied to the battery cell 30.

It will be appreciated that, in the case where the first surface 412a and the second surface 412b are simultaneously disposed to protrude toward the second metal member 42, the portion where the welding head 50 is attached to the second surface 412b is disposed to protrude toward the second surface 412b, and for example, the welding head 50 shown in fig. 18 may be used to perform laser welding on the first metal member 41 and the second metal member 42 shown in fig. 14 to 16. In the case where the first surface 412a and the second surface 412b are simultaneously protruded in the direction away from the second metal member 42, the portion where the bonding head 50 is bonded to the second surface 412b is recessed away from the second surface 412b, for example, the bonding head 50 shown in fig. 9 may be used to perform laser welding on the first metal member 41 and the second metal member 42 shown in fig. 6 to 8, and the bonding head 50 shown in fig. 13 may be used to perform laser welding on the first metal member 41 and the second metal member 42 shown in fig. 10 to 11.

According to the welding component 40 provided by the embodiment of the application, the first surface 412a and the second surface 412b of the welding area 412 of the first metal piece 41 are arranged to protrude towards the same side relative to the body 411, at least part of the welding portion 421 of the second metal piece 42 is attached to at least part of the first surface 412a, and the shape of the welding head 50 can be matched with that of the second surface 412b in the ultrasonic welding process of the first metal piece 41 and the second metal piece 42, so that on the premise that the radial size of the welding head 50 is not increased, the effective welding area of the welding head 50 to the first metal piece 41 and the second metal piece 42 is increased, and further, the welding reliability of the first metal piece 41 and the second metal piece 42 is improved.

In some embodiments, the first metal piece 41 includes a plurality of welding areas 412, the plurality of welding areas 412 being spaced apart. The second metal piece 42 includes a plurality of welding portions 421, and the welding portions 421 are disposed in one-to-one correspondence with the welding regions 412.

The arrangement of the first metal piece 41 having a plurality of welding areas 412 and the arrangement of the second metal piece 42 having a plurality of welding portions 421 corresponding to the welding areas 412 allows the first metal piece 41 and the second metal piece 42 to be ultrasonically welded a plurality of times, which is advantageous for increasing the effective welding area of the first metal piece 41 and the second metal piece 42, improving the welding reliability of the first metal piece 41 and the second metal piece 42, and further improving the overcurrent capability of the battery cell 30 in the case that the welding member 40 is applied to the battery cell 30.

As shown in fig. 6 to 8 and fig. 10 to 12, in some embodiments, the first surface 412a and the second surface 412b of the at least one welding area 412 are convexly disposed toward a direction away from the second metal piece 42, and the at least one welding portion 421 includes a protrusion 421a convexly disposed toward the first metal piece 41, and at least a portion of the protrusion 421a is in contact with the first surface 412 a.

In this way, the protruding portion 421a may be completely attached to the first surface 412a, and in the process of performing ultrasonic welding on the first metal piece 41 and the second metal piece 42, the protruding portion 421a is completely attached to the first surface 412a, so that the shape of the welding head 50 is adapted to the shape of the second surface 412b by providing a suitable structure of the welding head 50, and at this time, the welding head 50 may be concavely disposed relative to the first metal piece 41, so as to achieve at least partial attachment of the welding head 50 to the second surface 412b, thereby increasing the effective welding area of the first metal piece 41 and the second metal piece 42.

As shown in fig. 14 to 16, in some embodiments, the first surface 412a and the second surface 412b of the at least one welding area 412 are convexly disposed toward the second metal piece 42, and the welding portion 421 includes a groove 421b recessed away from the first metal piece 41, and at least a portion of the groove 421b is in contact with the first surface 412 a.

In this way, the groove 421b may be completely attached to the first surface 412a, and in the process of performing ultrasonic welding on the first metal piece 41 and the second metal piece 42, the groove 421b is attached to the first surface 412a, so that the shape of the welding head 50 is adapted to the shape of the second surface 412b by setting a suitable structure of the welding head 50, at this time, the welding head 50 may be convexly disposed with respect to the first metal piece 41, so as to achieve at least partial attachment of the welding head 50 to the second surface 412b, thereby increasing the effective welding area of the first metal piece 41 and the second metal piece 42.

In some embodiments, first metal piece 41 is sheet-shaped and weld area 412 is formed by a stamping process.

The first metal piece 41 is sheet-shaped, the welding area 412 is formed through a stamping process, so that the welding area 412 is convenient to process and shape, the first surface 412a and the second surface 412b of the welding area 412 formed after stamping are parallel to each other, the equal thickness of each part corresponding to the welding area 412 is set, and after the welding of the first metal piece 41 and the second metal piece 42 is finished, the welding uniformity of the welding area 412 and the welding part 421 is improved, and the welding quality of the first metal piece 41 and the second metal piece 42 is improved.

As shown in fig. 16 and 17, in some embodiments, the welding region 412 has at least one first recess 4121, the first recess 4121 being disposed concave toward the second metal 42; the welding portion 421 has at least one second concave portion 4211, the second concave portion 4211 is concave away from the first metal member 41, and the first concave portion 4121 and the second concave portion 4211 are bonded to each other.

The first recess 4121 is disposed concave toward the second metal member 42, and the positions of the first recess 4121 corresponding to the first surface 412a and the second surface 412b are disposed concave toward the second metal member 42.

The second recess 4211 is concave away from the first metal member 41, and the first recess 4121 and the second recess 4211 are mutually fitted, so that the shapes of the first recess 4121 and the second recess 4211 are matched, and the first recess 4121 and the second recess 4211 can be mutually fitted.

The welding region 412 may have one or more first recesses 4121, and similarly, the welding portion 421 may have one or more second recesses 4211 such that the second recesses 4211 are disposed in one-to-one correspondence with the first recesses 4121.

In the process of welding the welding region 412 of the first metal piece 41 and the welding portion 421 of the second metal piece 42 using the welding head 50 shown in fig. 18, the welding head 50 is provided with the welding teeth 52 protruding therefrom, and the welding region 412 and the welding portion 421 are pressed and rubbed by the welding teeth 52, so that the interface between the first metal piece 41 and the second metal piece 42 generates high temperature to reach or approach the metal recrystallization temperature to cause plastic deformation, and as the welding process continues, a certain shaping flow occurs between the first metal piece 41 and the second metal piece 42 and a metal bond is formed.

In this way, in the process of ultrasonic welding the first metal piece 41 and the second metal piece 42 by the welding head 50, the welding teeth 52 of the welding head 50 press the welding region 412 of the first metal piece 41 and the welding portion 421 of the second metal piece 42, and after the welding of the first metal piece 41 and the second metal piece 42 is completed, the first concave portions 4121 and the second concave portions 4211 corresponding to the number of the welding teeth 52 are formed in the welding region 412 of the first metal piece 41 and the welding portion 421 of the second metal piece 42.

Therefore, the first concave portion 4121 of the welding region 412 of the first metal member 41 and the second concave portion 4211 of the welding portion 421 of the second metal member 42 are bonded to each other, and the welding region 412 and the welding portion 421 can be pressed and rubbed by the welding teeth 52 of the welding head 50 during the welding of the welding region 412 and the welding portion 421, so that plastic flow is generated in the welding region 412 and the welding portion 421 and metal bonding is formed, thereby improving the welding reliability of the first metal member 41 and the second metal member 42.

As shown in fig. 16, in some embodiments, the welding area 412 is semi-ellipsoidal or truncated cone-shaped, the welding area 412 is protruding toward the second metal piece 42 relative to the body 411, and the second metal piece 42 points in the direction of the first metal piece 41, and the cross section of the welding area 412 tends to increase.

The welding area 412 is semi-ellipsoidal or truncated cone-shaped, and the welding head 50 has a shape matching with the welding area 412, so that the welding area 412 and the welding portion 421 are respectively in regular shapes, and the welding area 412 and the effective welding area of the welding portion 421 are increased, so that the welding area 412 can be conveniently machined and molded. The welding area 412 is protruded toward the second metal member 42 with respect to the main body 411, so that the welding head 50 has a shape matching with the welding area 412, and in the case of using the welding head 50 shown in fig. 18 to protrude toward the second surface 412b, the second metal member 42 is disposed to be directed toward the first metal member 41, the cross section of the welding area 412 tends to increase, and in the process of attaching the welding head 50 to the second surface 412b, the convenience of the welding head 50 and the second surface 412b can be improved.

As shown in fig. 8 and 12, in some embodiments, the welding area 412 is semi-ellipsoidal or truncated cone-shaped, the welding area 412 is disposed opposite to the second metal piece 42 with respect to the body 411, and the second metal piece 42 points to the direction of the first metal piece 41, and the cross section of the welding area 412 is in a decreasing trend.

The welding area 412 is semi-ellipsoidal or truncated cone-shaped, and the welding head 50 has a shape matching with the welding area 412, so that the welding area 412 and the welding portion 421 are respectively in regular shapes, and the welding area 412 and the effective welding area of the welding portion 421 are increased, so that the welding area 412 can be conveniently machined and molded. The welding area 412 is protruded away from the second metal member 42 with respect to the main body 411, so that the welding head 50 has a shape matching with the welding area 412, and the welding head 50 shown in fig. 9 can be used to weld the welding component 40 shown in fig. 8, while the welding head 50 shown in fig. 13 is used to weld the welding component 40 shown in fig. 12, that is, when the welding head 50 is concavely disposed away from the second surface 412b, the second metal member 42 is disposed to point to the direction of the first metal member 41, and the cross section of the welding area 412 is in a decreasing trend, so that the convenience of the welding head 50 matching with the second surface 412b is improved in the process of bonding the welding head 50 with the second surface 412 b.

As shown in fig. 7, in some embodiments, the maximum dimension d of the orthographic projection of the second surface 412b at the body portion 411 satisfies: d is more than or equal to 50mm and less than or equal to 50mm.

The orthographic projection of the second surface 412b on the body 411 may be circular or elliptical, and the maximum dimension d of the orthographic projection of the second surface 412b on the body 411 is the maximum dimension inside the orthographic projection of the second surface 412b on the body 411, and in the case that the orthographic projection of the second surface 412b on the body 411 is circular, d is the diameter of the circle.

Alternatively, d may be 30mm, 35mm, 40mm, 45mm, 50mm, or the like.

Since the diameter of the welding head 50 is mostly between 30mm and 50mm, and the welding head 50 is attached to the second surface 412b during the welding of the first metal piece 41 and the second metal piece 42, the setting of d is 50mm less than or equal to 50mm, which is beneficial to increasing the contact area between the second surface 412b and the welding head 50 without increasing the radial dimension of the welding head 50, and is further beneficial to increasing the effective welding area of the first metal piece 41 and the second metal piece 42.

As shown in fig. 6, 19 and 20, the battery cell 30 provided according to the embodiment of the present application includes the welding member 40 provided in any one of the above embodiments.

The battery cell 30 provided in the embodiment of the present application may be a cylindrical battery cell, a directional battery cell, a soft pack battery cell, or the like.

Alternatively, the first metal piece 41 of the welding member 40 may be at least part of the current collector 34 of the battery cell 30, and the second metal piece 42 may be at least part of the electrode terminal 33 of the battery cell 30; alternatively, the first metal piece 41 of the welding part 40 may be at least part of the tab 322 of the battery cell 30, and the second metal piece 42 may be at least part of the electrode terminal 33 of the battery cell 30; alternatively, the first metal piece 41 of the welding member 40 may be at least part of the tab 322 of the battery cell 30, and the second metal piece 42 may be at least part of the current collector 34 of the battery cell 30.

The battery unit 30 provided in this embodiment of the present application, due to the adoption of the welding component 40 provided in any one of the embodiments, the first metal piece 41 and the second metal piece 42 of the welding component 40 have a relatively high effective welding area, which is beneficial to improving the welding reliability of the first metal piece 41 and the second metal piece 42, and is beneficial to improving the overcurrent capacity of the battery unit 30, and is further beneficial to improving the reliability of the battery unit 30.

As shown in fig. 4, 5, 19, and 20, in some embodiments, the electrode terminal 33 of the battery cell 30 includes a second metal member 42, and the current collector 34 of the battery cell 30 includes a first metal member 41. The current collector 34 electrically connects the electrode terminal 33 with the tab 322 of the electrode assembly 32.

The battery cell 30 may be a cylindrical battery cell or a prismatic battery cell, and in the case that the battery cell 30 is a prismatic battery cell, the current collector 34 may be sheet-shaped and electrically connect the tab 322 of the electrode assembly 32 with the structure of the electrode terminal 33, and the tab 322 of the electrode assembly 32 protrudes from the electrode body 321 of the electrode assembly 32. In the case of the cylindrical battery cell 30, the current collector 34 may have a disk shape, and the tab 322 of the electrode assembly 32 is welded to the disk-shaped current collector 34 after being flattened.

Alternatively, the second metal member 42 may be the whole of the electrode terminal 33, or the second metal member 42 may be a part of the electrode terminal 33. Similarly, the first metal member 41 may be the entire current collector 34, or the first metal member 41 may be a part of the structure of the current collector 34.

By such arrangement, after the electrode terminal 33 and the current collector 34 are welded, the effective welding area of the electrode terminal 33 and the current collector 34 can be increased, which is beneficial to improving the connection reliability of the electrode terminal 33 and the current collector 34, improving the overcurrent capacity of the battery cell 30, and further improving the reliability of the battery cell 30.

In some embodiments, the electrode terminal 33 of the battery cell 30 includes the second metal member 42, and the tab 322 of the electrode assembly 32 of the battery cell 30 includes the first metal member 41, and the tab 322 is welded to the electrode terminal 33.

The battery cell 30 may be a prismatic battery cell, alternatively, the second metal member 42 may be the whole of the electrode terminal 33, or the second metal member 42 may be a part of the structure of the electrode terminal 33, and similarly, the first metal member 41 may be the whole of the tab 322, or the first metal member 41 may be a part of the structure of the tab 322.

The tab 322 is directly welded to the electrode terminal 33 without using a transfer member, which is advantageous in saving space inside the battery cell 30 and improving energy density of the battery cell 30.

The electrode terminal 33 provided with the battery cell 30 includes the second metal member 42, the tab 322 includes the first metal member 41, which is favorable for improving the connection reliability of the tab 322 and the electrode terminal 33, and is favorable for improving the effective welding area of the electrode terminal 33 and the tab 322, thereby improving the overcurrent capacity of the battery cell 30 and further improving the reliability of the battery cell 30.

As shown in fig. 2 to 5, the battery 10 provided according to the embodiment of the present application includes the welding member 40 provided in any of the above embodiments, or includes the battery cell 30 provided in any of the above embodiments.

In the case where the welding member 40 is applied to the battery 10, the first metal piece 41 of the welding member 40 may be provided as at least part of the bus bar 13, and the second metal piece 42 may be provided as at least part of the electrode terminal 33, and the first metal piece 41 and the second metal piece 42 may be welded to each other to electrically connect the bus bar 13 and the electrode terminal 33, thereby realizing series connection or parallel connection of the plurality of battery cells 30.

The battery 10 provided in the embodiment of the present application has the same technical effects due to the welding component 40 or the battery cell 30 provided in the embodiment of the present application, and will not be described herein again.

As shown in fig. 9, 13 and 18, the welding head 50 provided according to the embodiment of the present application includes a welding head body 51 and a tooth 52, one end of the welding head body 51 has a welding surface 51a, the welding surface 51a is arc-shaped and is used to cooperate with the second surface 412b of the first metal piece 41 of the welding component 40 provided in any of the above embodiments to weld the welding region 412 and the welding portion 421, and the tooth 52 is provided on the welding surface 51a.

The welding head body 51 of the welding head 50 has a welding surface 51a, the welding surface 51a cooperating with at least part of the second surface 412b to effect welding of the welding region 412 of the first metal piece 41 and the weld 421 of the second metal piece 42. The welding teeth 52 are provided on the welding head body 51, and during the ultrasonic welding process, the welding teeth 52 generate extrusion and friction to the welding area 412 and the welding, which is beneficial to improving the welding quality of the first metal piece 41 and the second metal piece 42.

Therefore, the welding head 50 provided in this embodiment of the present application is configured to have the welding surface 51a by providing the welding head body 51 and providing the welding surface 51a to be matched with the second surface 412b of the first metal part 41 of the welding component 40 provided in any one of the embodiments described above, so that the welding head 50 is used to perform ultrasonic welding on the first metal part 41 and the second metal part 42 of the welding component 40 provided in this embodiment of the present application, which is beneficial to improving the effective welding area of the first metal part 41 and the second metal part 42 without increasing the radial dimension of the welding head 50, and is beneficial to improving the overcurrent capability of the battery cell 30 when the welding component 40 is applied in the battery cell 30, thereby improving the reliability of the battery cell 30.

With continued reference to fig. 9, 13 and 18, in some embodiments, the bonding tool body 51 has a protrusion 511 or a recess 512, and the bonding surface 51a is an outer surface of the protrusion 511 or the bonding surface 51a is an inner wall of the recess 512.

The shape of the welding surface 51a of the horn body 51 is also changed adaptively according to the difference in the protruding direction of the second surface 412b of the first metal member 41 with respect to the body 411. In the case where the second surface 412b is provided to protrude in a direction toward the second metal 42 with respect to the body portion 411, the second surface 412b is provided to be recessed with respect to the horn body 51, and at this time, the horn body 51 may be provided with a protrusion 511, and the welding surface 51a is an outer surface of the protrusion 511 to achieve engagement of the welding surface 51a with the second surface 412 b. In the case where the second surface 412b is disposed to protrude in a direction opposite to the second metal member 42 with respect to the body portion 411, the second surface 412b may be disposed to protrude with respect to the bonding tool body 51, and in this case, the bonding tool body 51 may be provided with a recess 512, and the bonding surface 51a may be an inner wall of the recess 512, so as to achieve the engagement of the bonding surface 51a with the second surface 412 b.

Therefore, the welding head body 51 is provided with the convex portion 511 or the concave portion 512, and the welding surface 51a is provided as the outer surface of the convex portion 511, or the welding surface 51a is provided as the inside of the concave portion 512, so that the cooperation of the welding surface 51a and the second surface 412b is facilitated, and the smooth welding work of the welding head 50 on the first metal piece 41 and the second metal piece 42 is facilitated.

In some embodiments, the welding component 40 provided according to the embodiments of the present application includes a first metal piece 41 and a second metal piece 42, where the first metal piece 41 includes a body portion 411 and at least one welding area 412, the welding area 412 is semi-ellipsoidal or truncated cone-shaped, the welding area 412 is protruding toward the second metal piece 42 relative to the body portion 411, the second metal piece 42 points to the direction of the first metal piece 41, and the cross section of the welding area 412 is in an increasing trend. The welding region 412 has opposite first and second surfaces 412a and 412b, the first and second surfaces 412a and 412b being convexly disposed toward the same side with respect to the body portion 411. The second metal piece 42 is disposed on a side of the first metal piece 41 near the first surface 412a, and the second metal piece 42 includes at least one welding portion 421, where at least a portion of the welding portion 421 is attached to at least a portion of the first surface 412 a. The first metal piece 41 is sheet-shaped, and the welding area 412 is formed by a stamping process. The welding area 412 has at least one first recess 4121, the first recess 4121 being arranged concave downward toward the second metal piece 42; the welding portion 421 has at least one second concave portion 4211, the second concave portion 4211 is concave away from the first metal member 41, and the first concave portion 4121 and the second concave portion 4211 are bonded to each other. The maximum dimension d of the orthographic projection of the second surface 412b at the body portion 411 satisfies: d is more than or equal to 30mm and less than or equal to 50mm.

The welding component 40 provided in this embodiment is beneficial to increasing the effective welding area of the welding head 50 to the first metal piece 41 and the second metal piece 42 without increasing the radial size of the welding head 50, and further is beneficial to improving the welding reliability of the first metal piece 41 and the second metal piece 42, and is beneficial to improving the overcurrent capacity of the battery cell 30 and further beneficial to improving the reliability of the battery cell 30 when the welding component 40 is applied to the battery cell 30.

While the present application has been described with reference to a preferred embodiment, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the present application, and in particular, the technical features mentioned in the various embodiments may be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions falling within the scope of the claims.

Claims

1. A welded component, comprising:

a first metal piece comprising a body portion and at least one weld zone having opposed first and second surfaces, the first and second surfaces being convexly disposed toward the same side relative to the body portion;

The second metal piece is arranged on one side, close to the first surface, of the first metal piece, and comprises at least one welding part, and at least part of the welding part is attached to at least part of the first surface.

2. The welded component of claim 1, wherein the first metal piece comprises a plurality of the weld areas, the plurality of weld areas being spaced apart; the second metal piece comprises a plurality of welding parts, and the welding parts are arranged in one-to-one correspondence with the welding areas.

3. The welded component of claim 1, wherein the first and second surfaces of at least one of the weld areas are convexly disposed in a direction away from the second metal piece, and at least one of the weld portions includes a convex portion convexly disposed in a direction toward the first metal piece, at least a portion of the convex portion conforming to the first surface.

4. The welded component of claim 1, wherein the first and second surfaces of at least one of the weld areas are convexly disposed toward the second metal piece, the weld including a groove recessed away from the first metal piece, at least a portion of the groove conforming to the first surface.

5. The welded component of claim 1, wherein the first metal piece is sheet-shaped and the weld area is formed by a stamping process.

6. The welded component according to claim 1, characterized in that the welding area has at least one first recess, which is arranged concave downwards in the direction of the second metal part; the welding part is provided with at least one second concave part, the second concave part is concave away from the first metal piece, and the first concave part and the second concave part are mutually attached.

7. The welded component according to any one of claims 1 to 6, wherein the welding area is semi-ellipsoidal or truncated cone-shaped, the welding area is provided protruding toward the second metal piece with respect to the body portion, the second metal piece is directed toward the first metal piece, and a cross section of the welding area is in an increasing tendency; or,

the welding area is semi-ellipsoidal or truncated cone-shaped, the welding area is arranged opposite to the second metal piece in a protruding mode relative to the body part, the second metal piece points to the direction of the first metal piece, and the section of the welding area is in a decreasing trend.

8. The welded component according to any one of claims 1 to 6, characterized in that the largest dimension d of the orthographic projection of the second surface at the body portion satisfies: d is more than or equal to 30mm and less than or equal to 50mm.

9. A battery cell comprising the welded component of any one of claims 1 to 8.

10. The battery cell of claim 9, wherein an electrode terminal of the battery cell comprises the second metal piece, and a current collector of the battery cell comprises the first metal piece, the current collector electrically connecting the electrode terminal with a tab of an electrode assembly.

11. The battery cell of claim 9, wherein the electrode terminal of the battery cell comprises the second metal piece, and the tab of the electrode assembly of the battery cell comprises the first metal piece, and the tab is welded to the electrode terminal.

12. A battery comprising the welded part according to any one of claims 1 to 8 or the battery cell according to any one of claims 9 to 11.

13. An electrical device comprising a battery as claimed in claim 12, said battery being arranged to provide electrical energy.

14. A welding head, characterized in that it comprises a welding head body having a welding surface at one end, which is arc-shaped and is adapted to cooperate with the second surface of the first metal part of the welding part according to any one of claims 1 to 8, so as to weld the welding area and the welding portion, and a welding tooth provided on the welding surface.

15. The welding head of claim 14, wherein the weld head body has a protrusion or a recess, the weld surface being an outer surface of the protrusion or the weld surface being an inner wall of the recess.