Welded member, battery cell, battery, and electric device

Abstract

The invention provides a welding part, a battery monomer, a battery and a power utilization device. The welding part comprises a first metal part and a second metal part, the first metal piece is provided with at least one welding pattern; the first metal piece and the second metal piece are welded and connected in an area where at least one welding pattern is located, and the welding pattern is arranged on the surface, deviating from the second metal piece, of the first metal piece; wherein one welding pattern is provided with a first straight edge and a second straight edge which are adjacent to each other, a first included angle is formed between the first straight edge and the second straight edge, and the first included angle is smaller than 90 degrees. According to the welding part provided by the invention, the first straight edge and the second straight edge can be utilized to repeatedly reflect welding energy such as laser between the first straight edge and the second straight edge, so that the absorption rate of a welding pattern to the welding energy such as the laser is improved, and the welding strength of the first metal part and the second metal part is favorably improved; and the risk of pseudo soldering or local weld penetration of the first metal piece and the second metal piece is reduced.

Description

Welding components, battery cells, batteries and electrical devices Technical Field

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

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

[0003] In the development of battery cell technology, in addition to improving cell performance, increasing the lifespan of cells is also a crucial issue that cannot be ignored. Improving the lifespan of cells significantly impacts energy conservation. Therefore, increasing the lifespan of cells is a key technical issue requiring continuous improvement in battery cell technology.

[0004] Summary of the Invention

[0005] The present application provides a welding component, a battery cell, a battery, and an electrical device, which can improve the cycle life of the battery cell.

[0006] In a first aspect, the welding component provided in an embodiment of the present application includes a first metal part and a second metal part; the first metal part has at least one welding pattern; the first metal part and the second metal part are welded together in the area where at least one welding pattern is located, and the welding pattern is arranged on the surface of the first metal part facing away from the second metal part; wherein, at least one welding pattern has adjacent first and second straight edges, the first straight edges and the second straight edges have a first angle, and the first angle is less than 90°.

[0007] The welding component provided in the embodiment of the present application is configured such that the welding pattern of the first metal part has adjacent first and second straight edges, the first and second straight edges have a first angle, and the first angle is configured to be less than 90°. In the process of welding the welding pattern and the second metal part, the first and second straight edges can be utilized to repeatedly reflect welding energy such as laser between the first and second straight edges, thereby improving the absorption rate of the welding pattern to welding energy such as laser, and further improving the utilization rate of the welding energy. This is beneficial to improving the welding strength of the first metal part and the second metal part, and reducing the risk of cold welding or partial welding through of the first metal part and the second metal part. In the embodiment in which the first metal part and the second metal part are applied to battery cells, it is beneficial to improving the cycle life of the battery cell.

[0008] In some embodiments, the first angle is less than or equal to 60°. This can further increase the number of reflections of welding energy, such as laser light, between the first straight edge and the second straight edge, thereby further increasing the absorption rate of welding energy, such as laser light, by the welding pattern, thereby improving the utilization rate of welding energy, and facilitating further improvement of the weld strength between the first metal member and the second metal member.

[0009] In some embodiments, the first angle is greater than or equal to 30° and less than or equal to 60°. During the processing of the welding pattern, the processing of the first straight edge and the second straight edge is facilitated, which is beneficial to improving the machinability of the welding pattern and improving the yield rate of the welding pattern processing.

[0010] In some embodiments, a welding pattern has at least two first angles, which is beneficial for further improving the absorption rate of the welding pattern to welding energy such as laser, thereby improving the welding strength between the welding pattern and the second metal part.

[0011] In some embodiments, the first straight edge and the second straight edge are connected by an arcuate edge, the first straight edge and the second straight edge are tangent to the arcuate edge, and the radius of curvature r of the arcuate edge satisfies: r≤0.1 mm. Arranging the first straight edge and the second straight edge to be connected by an arcuate edge facilitates processing of the welding pattern, and setting r≤0.1 mm helps ensure that the spacing between the first straight edge and the second straight edge allows for repeated reflection of the laser between the two edges, thereby improving laser utilization.

[0012] In some embodiments, the length l1 of the first straight side satisfies the following conditions: 0.1 mm ≤ l1 ≤ 1 mm; and / or the length l2 of the second straight side satisfies the following conditions: 0.1 mm ≤ l2 ≤ 1 mm. This configuration can improve the utilization of welding energy, such as laser energy, so that the weld pattern absorbs more energy and improves weld strength.

[0013] In some embodiments, the second metal member and the first metal member are arranged along a first direction, the first straight edge, the second straight edge, and the connection of the first and second straight edges away from the first angle form a first sub-area. The sum of the areas of the projections of the first sub-area of ​​the weld pattern on the first metal member along the first direction is S1, the area of ​​the projection of the weld pattern on the first metal member along the first direction is S, and S1 / S ≥ 70%. This helps improve the utilization of energy such as laser light, thereby enhancing the weld strength between the first and second metal members.

[0014] In some embodiments, the first metal member and the second metal member are arranged along a first direction, and the projection area S of at least one welding pattern along the first direction on the first metal member satisfies: 0.1 mm 2 ≤S≤0.3mm 2Such an arrangement can improve the absorption rate of the welding pattern to welding energy such as laser, thereby improving the strength of the welding connection between the first metal member and the second metal member.

[0015] In some embodiments, 0.12 mm 2 ≤S≤0.2mm 2 This is beneficial for further improving the absorption rate of the welding pattern to welding energy such as laser, further improving the welding strength between the first metal member and the second metal member, and thus improving the strength of the weld connection between the two.

[0016] In some embodiments, the first and second metal members are arranged along a first direction, and the projection of at least one weld pattern onto the first metal member along the first direction forms a triangle, with the lengths a and b of any two adjacent sides of the triangle satisfying the condition a ≤ b / 2. This arrangement facilitates forming a first angle, allowing laser light to be repeatedly reflected from both sides of the first angle, thereby increasing the weld pattern's absorption rate of the laser light and improving weld strength.

[0017] In some embodiments, the triangle is an isosceles triangle; and / or the triangle is a right triangle. The weld pattern has at least two first included angles, and can have up to three first included angles. When the laser is irradiated onto any area of ​​the weld pattern, it can be repeatedly reflected between the first straight edge and the second straight edge, further facilitating increased laser absorption by the weld pattern and improving weld strength.

[0018] In some embodiments, the first and second metal members are arranged along a first direction, and the projection of at least one weld pattern onto the first metal member along the first direction forms a quadrilateral, with the lengths d1 and d2 of the two diagonals of the quadrilateral satisfying the following: d1 ≤ d2 / 2. This arrangement allows laser light to illuminate a large portion of the corresponding weld pattern, resulting in repeated reflections between the first and second straight edges. This further improves the weld pattern's absorption rate of the laser light, thereby enhancing the weld strength between the first and second metal members.

[0019] In some embodiments, the first metal member and the second metal member are arranged along a first direction, and the projection of at least one welding pattern on the first metal member along the first direction is a parallelogram. With this arrangement, the corresponding welding pattern has at least two first angles. During welding of the welding pattern, welding energy, such as laser energy, is repeatedly reflected at the first straight edge and the second straight edge after being irradiated by the welding pattern. The reflected laser energy is more evenly irradiated on the welding pattern, which helps to increase the welding pattern's absorption rate of the laser energy, further improves the weld strength between the welding pattern and the second metal member, and reduces the risk of a cold weld or weld perforation between the welding pattern and the second metal member.

[0020] In some embodiments, at least one welding pattern includes a protrusion that protrudes away from the second metal member. This facilitates machining of the welding pattern while ensuring welding strength between the welding pattern and the second metal member, thereby improving the machinability of the welding pattern.

[0021] In some embodiments, at least one welding pattern includes a recessed portion that is recessed toward the second metal member, thereby facilitating processing of the welding pattern while ensuring welding strength between the welding pattern and the second metal member, thereby improving the processability of the welding pattern.

[0022] In some embodiments, along the arrangement direction of the first metal member and the second metal member, the dimension h of the weld pattern satisfies the following conditions: 0.03 mm ≤ h ≤ 0.5 mm. This arrangement helps reduce the difficulty of machining the weld pattern while ensuring the weld strength between the weld pattern and the second metal member, thereby improving the machinability of the weld pattern.

[0023] In some embodiments, 0.03 mm ≤ h ≤ 0.11 mm. In this way, the difficulty of processing the welding pattern can be further reduced, and the machinability of the welding pattern can be improved, while ensuring the welding strength between the welding pattern and the second metal member.

[0024] In some embodiments, there are multiple welding patterns, each of which is spaced apart. During the welding process, the multiple welding patterns simultaneously absorb welding energy such as laser light, melt, and solidify to connect with the second metal member, thereby further improving the weld strength between the first metal member and the second metal member.

[0025] In some embodiments, multiple welding patterns are evenly spaced along the second direction; and / or multiple welding patterns are evenly spaced along the third direction, with the first metal member and the second metal member arranged along the first direction, and the first, second, and third directions intersecting with each other. This arrangement helps improve the absorption rate of laser energy or other energy absorbed by the welding patterns during welding of the first and second metal members, thereby improving the weld strength between the first and second metal members.

[0026] In some embodiments, the minimum spacing m between two adjacent weld patterns satisfies the following conditions: 0.1 mm ≤ m ≤ 2 mm. This helps maximize the weld pattern's absorption rate of laser or other welding energy, thereby maximizing the weld strength between the first and second metal parts and reducing the likelihood of partial weld penetration or cold welds.

[0027] In some embodiments, 0.2 mm ≤ m ≤ 0.8 mm. This configuration can maximize the absorption rate of the welding pattern to welding energy such as laser energy, thereby maximizing the welding strength between the first metal member and the second metal member and reducing the possibility of local weld penetration or cold weld.

[0028] In a second aspect, an embodiment of the present application provides a battery cell comprising a welding component as in any embodiment of the first aspect.

[0029] The battery cell provided in the embodiment of the present application has the same technical effect as that provided in any of the above embodiments because it adopts the welding component provided in any of the above embodiments, and thus will not be described in detail here.

[0030] In some embodiments, the electrode terminals of the battery cells include a second metal member, and the adapters of the battery cells include a first metal member. The adapters electrically connect the electrode terminals to the tabs of the electrode assembly. This arrangement improves the connection reliability between the electrode terminals and the adapters, reduces the risk of electrical connection failure between the electrode terminals and the adapters, and improves the cycle life of the battery cells.

[0031] In some embodiments, the electrode terminal of a battery cell includes a second metal member, and the tab of the electrode assembly of the battery cell includes a first metal member. The tab is welded to the electrode terminal. This improves the reliability of the connection between the tab and the electrode terminal and reduces the risk of connection failure due to cold welding or welding through, thereby improving the cycle life of the battery cell.

[0032] In a third aspect, an embodiment of the present application provides a battery, comprising a welding component provided in the embodiment of the first aspect or a battery cell provided in the embodiment of the second aspect.

[0033] The battery provided in the embodiment of the present application has the same technical effect as the welding components or battery cells provided in the embodiment of the present application, and will not be described in detail here.

[0034] In a fourth aspect, an embodiment of the present application provides an electrical device, comprising a battery as in the embodiment of the third aspect, the battery being used to provide electrical energy.

[0035] The electrical device provided in the embodiment of the present application has the same technical effects as the battery provided in the embodiment of the present application, and thus will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings without creative work.

[0037] FIG1 is a schematic structural diagram of a vehicle provided in one embodiment of the present application;

[0038] FIG2 is a schematic diagram of an explosion of a battery provided in one embodiment of the present application;

[0039] FIG3 is a schematic structural diagram of a battery module in a battery provided in an embodiment of the present application;

[0040] FIG4 is a schematic diagram of an explosion of a battery cell provided in some embodiments of the present application;

[0041] FIG5 is a front view of a welding component provided in an embodiment of the present application;

[0042] FIG6 is a partial enlarged view of point A in FIG5 ;

[0043] FIG7 is a schematic cross-sectional view of the structure along line BB in FIG5 ;

[0044] FIG8 is a front view of a welding pattern in a welding component provided in an embodiment of the present application;

[0045] FIG9 is a front view of a cross section of a welding pattern in a welding component provided in an embodiment of the present application;

[0046] FIG10 is a front view of another cross section of a welding pattern in a welding component provided in an embodiment of the present application;

[0047] FIG11 is a partial enlarged view of point C in FIG7 ;

[0048] FIG12 is a partial enlarged view of point D in FIG7 .

[0049] In the drawings, the drawings are not drawn to scale.

[0050] Description of reference numerals:

[0051] 1. Vehicle; 1a. Motor; 1b. Controller;

[0052] 10. Battery; 11. First housing; 12. Second housing;

[0053] 20. Battery module;

[0054] 30. Battery cell; 31. Housing; 311. Shell; 311a. Opening; 312. End cap; 32. Electrode assembly; 321. Tab; 33. Electrode terminal; 34. Adapter;

[0055] 40. Welding component; 41. First metal member; 411. Welding pattern; 411b. Protrusion; 411c. Concave portion; 4111. First straight edge; 4112. Second straight edge; 4113. Arc edge; α. First angle; 42. Second metal member;

[0056] 50. Busbars;

[0057] X, first direction; Y, second direction; Z, third direction. DETAILED DESCRIPTION

[0058] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0059] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0060] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0061] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0062] The term "and / or" in this application simply describes the relationship between related objects, indicating that three possible relationships exist. For example, C and / or D can mean: C exists alone, C and D exist simultaneously, or D exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0063] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0064] The term "plurality" used in this application refers to two or more (including two).

[0065] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.

[0066] In some embodiments, the battery may be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0067] In some embodiments, the battery may be a battery pack, which includes a case and battery cells, wherein the battery cells or battery modules are housed in the case.

[0068] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0069] In some embodiments, the battery may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0070] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0071] The battery cells can be lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-hydrogen batteries, nickel-cadmium batteries, lead-acid batteries, etc., which are not limited in the embodiments of the present application.

[0072] A battery cell typically includes an electrode assembly. This assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of a battery cell, active ions (such as lithium ions) are inserted and removed between the positive and negative electrodes. The separator, placed between the positive and negative electrodes, prevents short circuits between the positive and negative electrodes while allowing the active ions to pass through.

[0073] 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.

[0074] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0075] 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.

[0076] 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.

[0077] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0078] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0079] In some embodiments, the electrode assembly is provided with tabs that can conduct current from the electrode assembly. The tabs include a positive tab and a negative tab.

[0080] In some embodiments, a battery cell may include a housing that is used to encapsulate components such as an electrode assembly and an electrolyte.

[0081] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell or a battery cell of other shapes. The prismatic battery cell includes a square-shell battery cell, a blade-shaped battery cell, and a polygonal battery. The polygonal battery is, for example, a hexagonal battery, etc. There is no special limitation in this application.

[0082] After discovering the problem of a short service life of battery cells, the inventors conducted a systematic analysis and research on the structure and operating process of battery cells. The results revealed that during the manufacturing process of battery cells, the electrode terminals need to be welded to the adapter or the electrode terminals to the tabs to achieve an electrical connection between the electrode terminals and the electrode assembly. However, during this welding process, welding energy, such as laser energy, is not fully absorbed by the welding area between the electrode terminals and the adapter or the tabs, resulting in a weak weld. As the number of charge and discharge cycles of the battery cells increases, or as the number of times the battery cells are subjected to vibration or impact loads increases, the connection between the electrode terminals and the adapter or the tabs fails, and the battery cells can no longer be charged or discharged, thus seriously affecting the service life of the battery cells.

[0083] Based on the above problems discovered by the inventors, the inventors have improved the structure of the battery cell. The technical solutions described in the embodiments of this application are applicable to welding components, battery cells containing welding components, batteries containing battery cells, and electrical devices using batteries.

[0084] A welded component provided according to an embodiment of the present application includes a first metal member and a second metal member. The first metal member has at least one welding pattern. The first metal member and the second metal member are welded together within a region where the at least one welding pattern is located. The welding pattern is disposed on a surface of the first metal member facing away from the second metal member. The at least one welding pattern has a first straight side and a second straight side adjacent to each other, the first straight side and the second straight side having a first angle formed therebetween, and the first angle being less than 90°.

[0085] The welding component provided in the embodiment of the present application is configured such that a welding pattern of a first metal part has adjacent first and second straight edges, the first and second straight edges have a first angle, and the first angle is less than 90°. During welding of the welding pattern and the second metal part, the gap between the first and second straight edges can be utilized to repeatedly reflect welding light, such as laser, thereby increasing the absorption rate of the welding pattern to welding light, such as laser, and thereby increasing the utilization rate of welding energy. This is beneficial to increasing the welding strength of the first metal part and the second metal part. In the embodiment where the first and second metal parts are applied to battery cells, this is beneficial to increasing the cycle life of the battery cells.

[0086] Electrical devices may include vehicles, mobile phones, portable devices, laptop computers, ships, spacecraft, electric toys, and electric tools, etc. Vehicles may include fuel vehicles, gas vehicles, or new energy vehicles. New energy vehicles may include pure electric vehicles, hybrid vehicles, or extended-range vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0087] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle and the battery as a battery pack as an example.

[0088] As shown in FIG1 , a battery 10 is provided inside a vehicle 1. The battery 10 may be provided at the bottom, head, or tail of the vehicle 1. The battery 10 may be used to power the vehicle 1, for example, the battery 10 may serve as an operating power source for the vehicle 1.

[0089] 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, to meet the power requirements of the vehicle 1 during starting, navigation, and driving.

[0090] In some embodiments of the present application, the battery 10 can not only serve as the operating power source of the vehicle 1, but also serve as the driving power source of the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0091] 2 , the battery 10 includes battery cells (not shown in FIG2 ) and may further include a case for accommodating the battery cells.

[0092] The box body is used to accommodate battery cells, and the box body can be of various structural forms. In some embodiments, the box body may include a first box body portion 11 and a second box body portion 12. The first box body portion 11 and the second box body portion 12 cover each other. The first box body portion 11 and the second box body portion 12 jointly define a storage space for accommodating battery cells. The second box body portion 12 can be a hollow structure with one end open, and the first box body portion 11 is a plate-like structure. The first box body portion 11 covers the open side of the second box body portion 12 to form a box body with a storage space; the first box body portion 11 and the second box body portion 12 can also be hollow structures with one side open. The open side of the first box body portion 11 covers the open side of the second box body portion 12 to form a box body with a storage space. Of course, the first box body portion 11 and the second box body portion 12 can be of various shapes, such as cylinders, cuboids, etc.

[0093] In order to improve the sealing performance after the first box body 11 and the second box body 12 are connected, a sealing member such as a sealant or a sealing ring may be provided between the first box body 11 and the second box body 12 .

[0094] Assuming that the first box body portion 11 covers the second box body portion 12 , the first box body portion 11 can also be referred to as an upper box cover, and the second box body portion 12 can also be referred to as a lower box body.

[0095] In the battery 10, there can be one or more battery cells. If there are multiple battery cells, they can be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections. Multiple battery cells can be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery module 20 is housed in a housing. Alternatively, multiple battery cells can be first connected in series, in parallel, or in a hybrid connection to form a battery module 20. Multiple battery modules 20 are then connected in series, in parallel, or in a hybrid connection to form a single unit, which is then housed in a housing.

[0096] In some embodiments, as shown in FIG3 , which is a schematic diagram of the structure of the battery module 20 shown in FIG2 , the battery module 20 includes multiple battery cells 30. The multiple battery cells 30 are first connected in series, parallel, or in a mixed series to form the battery module 20. The multiple battery modules 20 are then connected in series, parallel, or in a mixed series to form a single unit, which is then housed in a housing.

[0097] In some embodiments, the multiple battery cells 30 in the battery module 20 may be electrically connected via a busbar to achieve parallel connection, series connection, or mixed connection of the multiple battery cells 30 in the battery module 20 .

[0098] Please refer to Figure 4, which is an exploded view of the battery cell 30 shown in Figure 3. The battery cell 30 provided in the embodiment of the present application includes an electrode assembly 32 and a housing 31. The housing 31 has a receiving cavity, and the electrode assembly 32 is received in the receiving cavity.

[0099] In some embodiments, the housing 31 may include a shell 311 and an end cap 312, wherein the shell 311 is a hollow structure with an opening on one side, and the end cap 312 covers the opening 311a of the shell 311 and forms a sealed connection to form a sealed space for accommodating the electrode assembly 32 and the electrolyte.

[0100] When assembling the battery cell 30 , the electrode assembly 32 may be placed in the housing 311 first, the end cap 312 may be placed over the opening of the housing 311 , and then the electrolyte may be injected into the housing 311 through the electrolyte injection port on the end cap 312 .

[0101] In some embodiments, the housing 31 may also be used to contain electrolyte, such as electrolyte solution. The housing 31 may have various structural forms.

[0102] FIG4 shows a schematic structural diagram of a battery cell provided in an embodiment of the present application.

[0103] The housing 311 can have a variety of shapes, such as a cylinder, a rectangular parallelepiped, etc. The shape of the housing 311 can be determined based on the specific shape of the electrode assembly 32. For example, if the electrode assembly 32 has a cylindrical structure, the housing 311 can also be a cylindrical structure. If the electrode assembly 32 has a rectangular parallelepiped structure, the housing 311 can also be a rectangular parallelepiped structure. In FIG4 , for example, both the housing 311 and the electrode assembly 32 have rectangular parallelepiped structures.

[0104] The shell 311 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc., and the embodiment of the present application does not impose any special restrictions on this.

[0105] There may be one or more electrode assemblies 32 housed in the housing 311. In FIG4 , there are two electrode assemblies 32 housed in the housing 311.

[0106] In some embodiments, the electrode assembly 32 further includes a positive electrode sheet, a negative electrode sheet, and a separator. The electrode assembly 32 may be a wound structure formed by winding the positive electrode sheet, the separator, and the negative electrode sheet. The electrode assembly 32 may also be a stacked structure formed by stacking the positive electrode sheet, the separator, and the negative electrode sheet.

[0107] The positive electrode sheet may include a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector. The negative electrode sheet may include a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative current collector. The separator is located between the positive and negative electrode sheets, isolating the positive and negative electrode sheets to reduce the risk of short circuits between the positive and negative electrode sheets.

[0108] The tabs 321 in the electrode assembly 32 are divided into positive tabs and negative tabs. The positive tab is the portion of the positive electrode current collector that is not coated with the positive electrode active material layer. The negative tab is the portion of the negative electrode current collector that is not coated with the negative electrode active material layer.

[0109] As shown in Figures 5, 6, and 7, a welding component 40 provided according to an embodiment of the present application includes a first metal member 41 and a second metal member 42. The first metal member 41 has at least one welding pattern 411. The first metal member 41 and the second metal member 42 are welded together in the region where the at least one welding pattern 411 is located. The welding pattern 411 is provided on the surface of the first metal member 41 facing away from the second metal member 42. The at least one welding pattern 411 has a first straight edge 4111 and a second straight edge 4112 adjacent to each other. The first straight edge 4111 and the second straight edge 4112 have a first angle α formed therebetween, and the first angle α is less than 90°.

[0110] The first metal part 41 and the second metal part 42 can be components in the battery cell 30 respectively. For example, the first metal part 41 is at least a part of the adapter 34, the second metal part 42 is at least a part of the electrode terminal 33, the first metal part 41 and the second metal part 42 are in contact, and the first metal part 41 is electrically connected to the tab 321. In this way, the electrical connection between the electrode terminal 33 and the tab 321 can be achieved; or, the first metal part 41 is at least a part of the electrode terminal 33, the second metal part 42 is at least a part of the tab 321, the first metal part 41 and the second metal part 42 are in contact, and the electrical connection between the electrode terminal 33 and the tab 321 can be achieved.

[0111] Of course, the first metal part 41 can also be set as a part of the electrode terminal 33, and the second metal part 42 can be set as a part of the busbar 50. The first metal part 41 and the second metal part 42 are welded together to realize the electrical connection between the electrode terminal 33 and the busbar 50, and realize the series or parallel connection of multiple battery cells 30 through the busbar 50.

[0112] It should be noted that the term "at least one" in the present description can refer to one, multiple, or all of the components, and the specific term can be selected based on actual needs. Accordingly, if the first metal member 41 has at least one welding pattern 411, then the first metal member 41 may have only one welding pattern 411 or multiple welding patterns 411. The multiple welding patterns 411 may be arranged in a regular pattern, such as a circular array or a rectangular array. Alternatively, the multiple welding patterns 411 may be arranged in an irregular pattern.

[0113] The welding pattern 411 may be a protrusion or a groove formed on the first metal part 41 . The welding pattern 411 may be formed by a deposition process, or the welding pattern 411 may be formed by etching, cutting, or other processes. The selection may be based on the specific structural type of the welding pattern 411 .

[0114] The first metal member 41 may be welded to the second metal member 42 only in the region with the welding pattern 411 , or the first metal member 41 may be welded to the second metal member 42 in both the region with the welding pattern 411 and the region without the welding pattern 411 .

[0115] A welding pattern 411 can be in the shape of a triangular prism, a quadrangular prism, or other polygonal prisms. Of course, the welding pattern 411 can also be in an irregular shape. For example, the cross section of the welding pattern 411 perpendicular to its own axis can be in the shape of a triangle, a quadrangle, a pentagonal star, or other irregular shapes.

[0116] Optionally, the first metal member 41 and the second metal member 42 are arranged along the first direction X, and the cross-sections of the welding pattern 411 along the first direction X may be equal, or the cross-sections of the welding pattern 411 along the first direction X may not be completely equal. In an embodiment where the cross-sections of the welding pattern 411 along the first direction X are not equal, the closer the welding pattern 411 is to the second metal member 41, the smaller its cross-sectional area along the first direction X may be.

[0117] The welding pattern 411 includes a first straight side 4111 and a second straight side 4112 , and the welding pattern 411 may be formed by only straight sides, or the welding pattern 411 may further have an arcuate side 4113 .

[0118] If the first straight side 4111 and the second straight side 4112 are adjacent, there are no other straight sides between either end of the first straight side 4111 and the second straight side 4112, but there may be curved sides. That is to say, if the first straight side 4111 and the second straight side 4112 are adjacent, the first straight side 4111 and the second straight side 4112 may be directly connected, or the first straight side 4111 and the second straight side 4112 may be connected via the curved side 4113.

[0119] In the embodiment where the first straight side 4111 and the second straight side 4112 are connected by the arcuate side 4113 , the first included angle α between the first straight side 4111 and the second straight side 4112 is the included angle between the planes where the first straight side 4111 and the second straight side 4112 are located.

[0120] If the first angle α is less than 90°, the first angle α may be 89°, 80°, 75°, 70°, 60°, 50°, 45°, 40°, 30°, 25°, 20° or 10°, etc.

[0121] One welding pattern 411 may have one first straight side 4111 and one second straight side 4112 , or one welding pattern 411 may have multiple first straight sides 4111 or multiple second straight sides 4112 .

[0122] A first included angle α between the first straight edge 4111 and the second straight edge 4112 is set to be less than 90°. During the welding process of the welding pattern 411 and the second metal part 42, after the welding energy, such as a laser light, is irradiated onto the first straight edge 4111 or the second straight edge 4112, the included angle between the first straight edge 4111 and the second straight edge 4112 is less than 90°. The laser light will be reflected on the first straight edge 4111 or the second straight edge 4112 and reflected onto the second straight edge 4112 or the first straight edge 4111. In this way, the welding light, such as the laser light, irradiated onto any one of the first straight edge 4111 and the second straight edge 4112 will be repeatedly reflected between the first straight edge 4111 and the second straight edge 4112, so as to be absorbed more by the first straight edge 4111 or the second straight edge 4112, thereby improving the utilization rate of the welding energy, such as the laser light, and thereby improving the welding strength of the first metal part 41 and the second metal part 42.

[0123] The welding component 40 provided in the embodiment of the present application is configured such that the welding pattern 411 of the first metal part 41 has adjacent first straight edges 4111 and second straight edges 4112, the first straight edges 4111 and the second straight edges 4112 have a first angle α, and the first angle α is configured to be less than 90°. During welding of the welding pattern 411 and the second metal part 42, the first straight edges 4111 and the second straight edges 4112 can be utilized to repeatedly reflect welding energy, such as laser, between the first straight edges 4111 and the second straight edges 4112, thereby increasing the absorption rate of the welding pattern 411 to welding energy, such as laser, and thereby increasing the utilization rate of the welding energy. This is beneficial to increasing the welding strength of the first metal part 41 and the second metal part 42, and reducing the risk of cold welding or partial welding through of the first metal part 41 and the second metal part 42. In the embodiment in which the first metal part 41 and the second metal part 42 are applied to the battery cell 30, this is beneficial to increasing the cycle life of the battery cell 30.

[0124] In some embodiments, the first angle α is less than or equal to 60°.

[0125] For example, the first angle α may be 60°, 50°, 45°, 40°, 35°, 30°, 25° or 20°, etc.

[0126] After systematic analysis and a large number of experiments, the inventors found that setting the first angle α to be less than or equal to 60° can further increase the number of reflections of welding energy, such as laser, between the first straight edge 4111 and the second straight edge 4112, so as to further improve the utilization rate of welding energy, which is conducive to further improving the welding strength of the first metal part 41 and the second metal part 42.

[0127] In some embodiments, the first angle α is greater than or equal to 30° and less than or equal to 60°.

[0128] For example, the first angle α may be 30°, 40°, 45°, 50° or 60°, etc.

[0129] After systematic analysis and a large number of experiments, the inventors found that setting the first angle α to be greater than or equal to 30° facilitates the processing of the first straight edge 4111 and the second straight edge 4112 during the processing of the welding pattern 411, which is beneficial to improving the machinability of the welding pattern 411 and improving the yield rate of the processing of the welding pattern 411.

[0130] In some embodiments, a welding pattern 411 has at least two first angles α.

[0131] According to different shapes of the welding pattern 411 , one welding pattern 411 may have two or more first angles α.

[0132] It can be understood that the more first angles α a welding pattern 411 has, the more first straight edges 4111 or second straight edges 4112 of the corresponding welding pattern 411. During the welding process of the welding pattern 411, the greater the absorption rate of the welding pattern 411 to welding energy such as laser is. This is conducive to further improving the absorption rate of the welding pattern 411 to welding energy such as laser, thereby improving the welding strength between the welding pattern 411 and the second metal part 42.

[0133] As shown in FIG8 , in some embodiments, the first straight edge 4111 and the second straight edge 4112 are connected by an arcuate edge 4113 , the first straight edge 4111 and the second straight edge 4112 are tangent to the arcuate edge 4113 , and the curvature radius r of the arcuate edge 4113 satisfies: r≤0.1 mm.

[0134] For example, the radius of curvature of the arc-shaped edge 4113 may be 0.1 mm, 0.08 mm, 0.06 mm, 0.05 mm, 0.04 mm or 0.02 mm, etc.

[0135] The first straight edge 4111 and the second straight edge 4112 are connected by the arc edge 4113 to facilitate the processing of the welding pattern 411, and setting r≤0.1mm is conducive to ensuring that the distance between the first straight edge 4111 and the second straight edge 4112 can enable the laser to be repeatedly reflected between the two, thereby improving the utilization rate of the laser.

[0136] In some embodiments, the side length l1 of the first straight side 4111 satisfies: 0.1 mm ≤ l1 ≤ 1 mm; and / or the side length l2 of the second straight side 4112 satisfies: 0.1 mm ≤ l2 ≤ 1 mm.

[0137] As an example, l1 can be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm or 1 mm, etc.

[0138] As an example, l2 can be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, or 1 mm, etc. It is understandable that the smaller the length l1 of the first straight side or the length l2 of the second straight side 4112 is, the fewer times the laser light is repeatedly reflected between the first straight side 4111 and the second straight side 4112. On the other hand, the larger the length l1 of the first straight side or the length l2 of the second straight side 4112 is, the greater the distance between the ends of the first straight side 4111 or the second straight side 4112 that are far away from each other is, which is less conducive to the reflection of the laser light between the two ends and occupies more space.

[0139] After systematic analysis and a large number of experiments, the inventors found that setting 0.1mm≤l1≤1mm, and / or 0.1mm≤l2≤1mm, can improve the absorption rate of the welding pattern to welding energy such as laser, so that the welding pattern 411 absorbs more energy and improves the welding strength of the first metal part 41 and the second metal part 42.

[0140] In some embodiments, the first metal member 41 and the second metal member are arranged along the first direction X, and the first straight edge 4111, the second straight edge 4112, and the connection between the first straight edge 4111 and the second straight edge 4112 at one end away from the first angle α form a first sub-area. The sum of the areas of the projections of the first sub-area of ​​the welding pattern 411 on the first metal member 41 along the first direction X is S1. The area of ​​the projection of the welding pattern 411 on the first metal member 41 along the first direction X is S, and S1 / S ≥ 70%.

[0141] A welding pattern 411 may have one or more first sub-regions. When a welding pattern 411 has multiple first sub-regions, S1 is the sum of the cross-sectional areas of all the first sub-regions of the welding pattern 411 along the first direction X.

[0142] When the cross-sections of the welding pattern 411 at various positions along the direction perpendicular to the first direction X are equal, the area of ​​the projection of the welding pattern 411 on the first metal part 41 along the first direction X is equal to the cross-sectional area of ​​the welding pattern 411 at the direction perpendicular to the first direction X; when the cross-sections of the welding pattern 411 at various positions along the direction perpendicular to the first direction X are not equal, the area of ​​the projection of the welding pattern 411 on the first metal part 41 along the direction X is equal to the area of ​​the largest cross-section of the welding pattern 411 at the direction perpendicular to the first direction X.

[0143] For example, S1 / S may be 70%, 75%, 80%, 85%, 90%, 95% or 100%, etc.

[0144] It is understood that laser or other welding energy is more likely to be reflected between the first straight edge 4111 and the second straight edge 4112 in the first sub-area, and is therefore more easily absorbed by the welding pattern 411. Therefore, setting S1 / S ≥ 70% is beneficial for further improving the energy utilization rate of laser or other welding energy.

[0145] In some embodiments, the first metal member 41 and the second metal member 42 are arranged along the first direction X, and the projection area S of at least one welding pattern 411 along the first direction X on the first metal member 41 satisfies: 0.1 mm 2 ≤S≤0.3mm 2 .

[0146] For example, S may be 0.1 mm. 2 , 0.12mm 2 , 0.15mm 2 , 0.16mm 2 , 0.18mm 2 , 0.2mm 2 , 0.25mm 2 , 0.28mm 2 or 0.3mm 2 wait.

[0147] After systematic analysis and a large number of experiments, the inventor found that setting 0.1mm 2 ≤S≤0.3mm 2 , which is beneficial to further improve the absorption rate of the welding pattern 411 to welding energy such as laser, thereby improving the strength of the welding connection between the two.

[0148] In some embodiments, 0.12 mm 2≤S≤0.2mm 2 .

[0149] For example, S may be 0.12 mm. 2 , 0.14mm 2 , 0.15mm 2 , 0.16mm 2 , 0.18mm 2 or 0.2mm 2 wait.

[0150] After further research and experiments, the inventor found that setting 0.12mm 2 ≤S≤0.2mm 2 This is beneficial to further reduce the area of ​​the first metal part 41 occupied by a single welding pattern 411 while ensuring that the welding pattern 411 has a high absorption rate of welding energy such as laser, and is beneficial to further improve the strength of the welding connection between the first metal part 41 and the second metal part 42.

[0151] As shown in FIG9 , in some embodiments, the first metal member 41 and the second metal member 42 are arranged along a first direction X, and the projection of at least one welding pattern 411 along the first direction X on the first metal member 41 is a triangle, and the lengths a and b of any two adjacent sides of the triangle satisfy: a≤b / 2.

[0152] The projection of the welding pattern 411 on the first metal part 41 along the first direction X is a triangle, so the cross-section of the welding pattern 411 perpendicular to the first direction X is a triangle, and the corresponding welding pattern 411 is a triangular prism. If a≤b / 2 is set, the angle relative to the side of the triangle with a length of a is the first angle α. Such a setting is conducive to forming the first angle α, so that the laser and the like are repeatedly reflected on both sides of the first angle α, thereby improving the absorption rate of the welding pattern 411 to the laser and helping to improve the welding strength.

[0153] In some embodiments, the triangle is an isosceles triangle; and / or, the triangle is a right triangle.

[0154] Optionally, the triangle is an isosceles triangle, or the triangle is a right triangle, or the triangle can be an isosceles right triangle.

[0155] When the triangle is an isosceles triangle, the welding pattern 411 has at least two first angles α, and can have up to three first angles α. Then, when the laser is irradiated to any area of ​​the corresponding welding pattern 411, it can be repeatedly reflected between the first straight edge 4111 and the second straight edge 4112, which is further beneficial to improve the absorption rate of the welding pattern 411 to the laser, thereby improving the welding strength between the first metal part 41 and the second metal part 42.

[0156] In the embodiment where the triangle is a right triangle, the corresponding welding pattern 411 has two first angles α, and when the laser is irradiated to any area of ​​the welding pattern 411, repeated reflection can occur between the first straight edge 4111 and the second straight edge 4112. This can further help improve the absorption rate of the welding pattern 411 to the laser, thereby improving the welding strength between the first metal part 41 and the second metal part 42.

[0157] As shown in FIG10 , in some embodiments, the first metal member 41 and the second metal member 42 are arranged along a first direction X, and the projection of at least one welding pattern 411 along the first direction X on the first metal member 41 is a quadrilateral, and the lengths d1 and d2 of the two diagonals of the quadrilateral satisfy: d1≤d2 / 2.

[0158] In this way, the two angles relative to the diagonal of the quadrilateral with a side length of d1 are both the first angle α. The laser irradiates most areas of the corresponding welding pattern 411, and can be repeatedly reflected between the first straight edge 4111 and the second straight edge 4112, which is further beneficial to improve the absorption rate of the welding pattern 411 to the laser, thereby improving the welding strength of the first metal part 41 and the second metal part 42.

[0159] Continuing to refer to FIG. 10 , in some embodiments, the first metal member 41 and the second metal member 42 are arranged along the first direction X, and the projection of at least one welding pattern 411 along the first direction X on the first metal member 41 is a parallelogram.

[0160] In some embodiments, at least one welding pattern 411 is diamond-shaped.

[0161] With such a configuration, the corresponding welding pattern 411 has at least two first angles α. During the welding process of the welding pattern 411, after welding energy such as laser is irradiated to the welding pattern 411, most of the energy can be repeatedly reflected at the first straight edge 4111 and the second straight edge 4112, and the reflected laser energy will be more evenly irradiated on the welding pattern 411, which is beneficial to ensure the absorption rate of the welding pattern 411 to welding energy such as laser, further improve the welding strength between the welding pattern 411 and the second metal part 42, and reduce the risk of cold welding or welding perforation between the welding pattern 411 and the second metal part 42.

[0162] In some embodiments, the projection of the welding pattern 411 on the first metal member 41 along the first direction X may be in the shape of a triangle, a parallelogram, or other shapes.

[0163] As shown in FIG. 7 and FIG. 11 , in some embodiments, at least one welding pattern 411 includes a protrusion 411 b , and the protrusion 411 b is protruded in a direction away from the second metal member 42 .

[0164] Optionally, each welding pattern 411 of a first metal member 41 may include a convex portion 411 b , or a portion of a plurality of welding patterns 411 of a first metal member 41 may include a convex portion 411 b , which may be selected according to actual needs.

[0165] Optionally, the protrusions 411b may be formed by etching or cutting, etc. For example, the area between the protrusions 411b is etched away on the first metal member 41 by a laser etching process, and only the protrusions 411b are retained.

[0166] The welding pattern 411 includes the protrusion 411 b , which facilitates the processing of the welding pattern 411 while ensuring the welding strength between the welding pattern 411 and the second metal member 42 , thereby improving the machinability of the welding pattern 411 .

[0167] As shown in FIG. 7 and FIG. 12 , in some embodiments, at least one welding pattern 411 includes a recessed portion 411 c , and the recessed portion 411 c is recessed toward the second metal member 42 .

[0168] Optionally, each welding pattern 411 of a first metal member 41 may be provided with a recessed portion 411 c , or a portion of a plurality of welding patterns 411 of a first metal member 41 may be provided with a recessed portion 411 c , which may be selected according to actual needs.

[0169] In this way, during the process of welding the welding pattern 411 and the second metal part 42, welding is performed on the side of the welding pattern 411 facing away from the second metal part 42, and the inner wall of the recess 411c is irradiated by the laser, absorbs energy and melts. The welding pattern 411 in the molten state contacts the first metal part 41 and is connected to the first metal part 41 as a whole during the solidification process. In this way, the welding connection between the first metal part 41 and the second metal part 42 is realized.

[0170] Optionally, the recess 411 c may be formed by punching, etching, cutting, etc. For example, a portion of the metal of the first metal member 41 is etched away by a laser etching process to form the recess 411 c.

[0171] The welding pattern 411 includes the recess 411 c , which facilitates the processing of the welding pattern 411 while ensuring the welding strength between the welding pattern 411 and the second metal member 42 , thereby improving the machinability of the welding pattern 411 .

[0172] In some embodiments, the welding pattern 411 includes both convex portions 411 b and concave portions 411 c .

[0173] As shown in FIG. 11 and FIG. 12 , in some embodiments, along the arrangement direction of the first metal member 41 and the second metal member 42 , a size h of the welding pattern 411 satisfies: 0.03 mm ≤ h ≤ 0.5 mm.

[0174] The arrangement direction of the first metal member 41 and the second metal member 42 is the first direction X. In the embodiment where the welding pattern 411 includes a convex portion 411b, the dimension h of the convex portion 411b along the first direction X is the dimension of the convex portion 411b protruding from other parts of the first metal member 41 along the first direction X. In the embodiment where the welding pattern 411 includes a concave portion 411c, the dimension h of the concave portion 411c along the first direction X is the depth of the concave portion 411c relative to other parts of the first metal member 41.

[0175] Illustratively, h may be 0.03 mm, 0.04 mm, 0.05 mm, 0.06 mm, 0.08 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm or 0.5 mm, etc.

[0176] After systematic analysis and numerous experiments, the inventors found that setting 0.03mm≤h≤0.5mm is beneficial to reducing the processing difficulty of the welding pattern 411 and improving the machinability of the welding pattern 411 while ensuring the welding strength between the welding pattern 411 and the second metal part 42.

[0177] In some embodiments, 0.03 mm ≤ h ≤ 0.11 mm.

[0178] Illustratively, h may be 0.03 mm, 0.04 mm, 0.05 mm, 0.06 mm, 0.08 mm, 0.1 mm or 0.11 mm, etc.

[0179] After further research, the inventors found that setting 0.03mm≤h≤0.11mm can further reduce the processing difficulty of the welding pattern 411 and improve the machinability of the welding pattern 411 while ensuring the welding strength between the welding pattern 411 and the second metal part 42.

[0180] In some embodiments, there are multiple welding patterns 411, and the multiple welding patterns 411 are arranged at intervals.

[0181] There are multiple welding patterns 411, and the multiple welding patterns 411 are arranged at intervals. During the welding process, the multiple welding patterns 411 simultaneously absorb welding energy such as laser, and the multiple welding patterns 411 melt and solidify and connect with the second metal part 42, which is beneficial to further improve the welding strength between the first metal part 41 and the second metal part 42.

[0182] Optionally, the plurality of welding patterns 411 may be regularly arranged in a circular array or a rectangular array, or the plurality of welding patterns 411 may be arranged on the first metal member 41 in any manner.

[0183] As shown in Figures 5 and 6, in some embodiments, multiple welding patterns 411 are evenly spaced along the second direction Y; and / or, multiple welding patterns 411 are evenly spaced along the third direction Z, the second metal member 42 is welded to the welding pattern 411 on one side of the first metal member 41 along the first direction X, and the first direction X, the second direction Y, and the third direction Z intersect with each other.

[0184] The plurality of welding patterns 411 are evenly spaced along the second direction Y, and the spacing between any two adjacent welding patterns 411 is equal along the second direction Y. The plurality of welding patterns 411 are evenly spaced along the third direction Z, and the spacing between any two adjacent welding patterns 411 is equal along the third direction Z.

[0185] The first direction X, the second direction Y, and the third direction Z intersect each other, and the angles between each of the first direction X, the second direction Y, and the third direction Z can be acute angles or right angles. For example, the first direction X, the second direction Y, and the third direction Z are perpendicular to each other.

[0186] The plurality of welding patterns 411 may be evenly spaced only along the second direction Y, or evenly spaced only along the third direction Z. Of course, the plurality of welding patterns 411 may be evenly spaced along both the second direction Y and the third direction Z.

[0187] A plurality of welding patterns 411 are arranged evenly spaced along at least one of the third direction Z and the second direction Y. During the welding process of the first metal part 41 and the second metal part 42, the welding patterns 411 can absorb as much welding energy as possible, such as laser energy, thereby improving the welding strength of the first metal part 41 and the second metal part 42.

[0188] As shown in FIG. 6 , in some embodiments, the minimum distance m between two adjacent welding patterns 411 satisfies: 0.1 mm≤m≤2 mm.

[0189] For example, the minimum distance m between two adjacent welding patterns 411 may be 0.1 mm, 0.12 mm, 0.15 mm, 0.18 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.5 mm, 0.8 mm, 1 mm, 1.5 mm, 1.8 mm or 2 mm, etc.

[0190] After systematic research and long-term practice, the inventors found that setting 0.1mm≤m≤2mm is conducive to maximizing the absorption rate of the welding pattern 411 to welding energy such as laser, so as to maximize the welding strength of the first metal part 41 and the second metal part 42 and reduce the possibility of local welding through or cold welding.

[0191] In some embodiments, 0.2 mm ≤ m ≤ 0.8 mm.

[0192] Illustratively, m may be 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm or 0.8 mm, etc.

[0193] After further research and experiments, the inventors found that setting 0.2mm≤m≤0.8mm can maximize the absorption rate of the welding pattern 411 to absorb welding energy such as laser, so as to maximize the welding strength of the first metal part 41 and the second metal part 42 and reduce the possibility of local welding through or cold welding.

[0194] The battery cell 30 provided according to an embodiment of the present application includes the welding component 40 provided in any of the above embodiments.

[0195] The battery cell 30 provided in the embodiment of the present application has the same technical effect as that provided in any of the above embodiments because it adopts the welding component 40 provided in any of the above embodiments, and therefore will not be described in detail here.

[0196] In some embodiments, the electrode terminal 33 of the battery cell 30 includes a second metal member 42 , the adapter 34 of the battery cell 30 includes a first metal member 41 , and the adapter 34 electrically connects the electrode terminal 33 and the tab 321 of the electrode assembly 32 .

[0197] Optionally, the second metal member 42 may be the entire electrode terminal 33, or the second metal member 42 may be a portion of the electrode terminal 33. Similarly, the first metal member 41 may be the entire adapter 34, or the first metal member 41 may be a portion of the adapter 34.

[0198] With such a configuration, during the welding process of the electrode terminal 33 and the adapter 34, the welding strength between the two can be improved, and the absorption rate of the adapter 34 to the laser can be increased, thereby reducing the risk of cold welding or welding through between the two, which is beneficial to improving the connection reliability of the electrode terminal 33 and the adapter 34, reducing the risk of electrical connection failure between the electrode terminal 33 and the adapter 34, and helping to improve the cycle life of the battery cell 30.

[0199] In some embodiments, the electrode terminal 33 of the battery cell 30 includes a second metal member 42 , the tab 321 of the electrode assembly 32 of the battery cell 30 includes a first metal member 41 , and the tab 321 is welded to the electrode terminal 33 .

[0200] Optionally, the second metal member 42 may be the entire electrode terminal 33 or a portion of the electrode terminal 33. Similarly, the first metal member 41 may be the entire tab 321 or a portion of the tab 321.

[0201] In this way, the tab 321 is directly welded to the electrode terminal 33 without going through the adapter 34 , which helps save space inside the battery cell 30 and improve the energy density of the battery cell 30 .

[0202] The electrode terminal 33 of the battery cell 30 includes a second metal part 42, and the tab 321 of the electrode assembly 32 of the battery cell 30 includes a first metal part 41, which is beneficial to improving the connection reliability between the tab 321 and the electrode terminal 33, and reducing the risk of connection failure due to cold welding or welding through. This is beneficial to improving the cycle life of the battery cell 30.

[0203] The battery 10 provided according to an embodiment of the present application includes the welding component 40 provided by any of the above embodiments or the battery cell 30 provided by the above embodiments.

[0204] In the battery 10, the first metal part 41 can be at least a part of the busbar 50, and the second metal part 42 can be at least a part of the electrode terminal 33 of the battery cell 30. The first metal part 41 and the second metal part 42 are welded together to achieve electrical connection between the busbar 50 and the electrode terminal 33, thereby achieving series or parallel connection of multiple battery cells 30.

[0205] Of course, the first metal member 41 and the second metal member 42 can be parts of the battery cell 30 respectively, and the electrical connection of related components inside the battery cell 30 is achieved through the welding connection between the first metal member 41 and the second metal member 42.

[0206] The battery 10 provided in the embodiment of the present application has the same technical effects as the welding component 40 or the battery cell 30 provided in the embodiment of the present application, and thus will not be described in detail here.

[0207] The electrical device provided according to the embodiment of the present application includes the battery 10 provided in the embodiment of the present application, and the battery 10 is used to provide electrical energy.

[0208] The electrical device provided in the embodiment of the present application has the same technical effects as the battery 10 provided in the embodiment of the present application, and thus will not be described in detail here.

[0209] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0210] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application.

Claims

1. A welding component, comprising: a first metal member having at least one welding pattern; a second metal member, wherein the first metal member and the second metal member are welded to each other in a region where the at least one welding pattern is located, and the welding pattern is provided on a surface of the first metal member facing away from the second metal member; At least one of the welding patterns has a first straight side and a second straight side adjacent to each other, the first straight side and the second straight side have a first included angle, and the first included angle is less than 90°.

2. The welding component according to claim 1, wherein The first angle is less than or equal to 60°.

3. The welding component according to claim 2, wherein: The first angle is greater than or equal to 30° and less than or equal to 60°.

4. The welding component according to any one of claims 1 to 3, wherein: One of the welding patterns has at least two of the first angles.

5. The welding component according to any one of claims 1 to 4, wherein: The first straight edge and the second straight edge are connected by an arcuate edge, the first straight edge and the second straight edge are tangent to the arcuate edge, and a curvature radius r of the arcuate edge satisfies: r≤0.1 mm.

6. The welding component according to any one of claims 1 to 5, wherein: The side length l1 of the first straight side satisfies: 0.1 mm ≤ l1 ≤ 1 mm; and / or the side length l2 of the second straight side satisfies: 0.1 mm ≤ l2 ≤ 1 mm.

7. The welding component according to any one of claims 1 to 6, wherein: The first metal part and the second metal part are arranged along a first direction, the first straight edge, the second straight edge, and the connection of the first straight edge and the second straight edge away from one end of the first angle form a first sub-area, the sum of the areas of the first sub-area of ​​the welding pattern projected on the first metal part along the first direction is S1, the area of ​​the projection of the welding pattern on the first metal part along the first direction is S, and S1 / S ≥ 70%.

8. The welding component according to any one of claims 1 to 7, wherein: The first metal member and the second metal member are arranged along a first direction, and the projection area S of at least one of the welding patterns along the first direction on the first metal member satisfies: 0.1 mm 2 ≤S≤0.3mm 2 .

9. The welding component according to claim 8, wherein 0.12mm 2 ≤S≤0.2mm 2 。 10. The welded component according to any one of claims 1 to 9, wherein: The first metal member and the second metal member are arranged along a first direction, and a projection of at least one welding pattern on the first metal member along the first direction is a triangle, and any two adjacent side lengths a and b of the triangle satisfy: a≤b / 2.

11. The welding component according to claim 10, wherein The triangle is an isosceles triangle; and / or, the triangle is a right triangle.

12. The welded component according to any one of claims 1 to 11, wherein: The first metal member and the second metal member are arranged along a first direction, a projection of at least one welding pattern on the first metal member along the first direction is a quadrilateral, and lengths d1 and d2 of two diagonals of the quadrilateral satisfy: d1≤d2 / 2.

13. The welded component according to any one of claims 1 to 12, wherein: The first metal member and the second metal member are arranged along a first direction, and a projection of at least one of the welding patterns on the first metal member along the first direction is a parallelogram.

14. The welded component according to any one of claims 1 to 13, wherein: At least one of the welding patterns includes a protrusion, and the protrusion is arranged to protrude in a direction away from the second metal member.

15. The welded component according to any one of claims 1 to 14, wherein: At least one of the welding patterns includes a recessed portion, and the recessed portion is recessed toward the second metal member.

16. The welded component according to any one of claims 1 to 15, wherein: Along the arrangement direction of the first metal member and the second metal member, a size h of the welding pattern satisfies: 0.03 mm ≤ h ≤ 0.5 mm.

17. The welding component according to claim 16, wherein 0.03mm≤h≤0.11mm.

18. The welded component according to any one of claims 1 to 17, wherein: There are a plurality of welding patterns, and the plurality of welding patterns are arranged at intervals.

19. The welding component according to claim 18, wherein The plurality of welding patterns are evenly spaced along the second direction; and / or, the plurality of welding patterns are evenly spaced along the third direction, the first metal member and the second metal member are arranged along the first direction, and the first direction, the second direction and the third direction intersect each other.

20. The welded component according to any one of claims 1 to 19, wherein: The minimum distance m between two adjacent welding patterns satisfies: 0.1 mm ≤ m ≤ 2 mm.

21. The welding component according to claim 20, wherein 0.2mm≤m≤0.8mm.

22. A battery cell comprising the welding component according to any one of claims 1 to 21.

23. The battery cell according to claim 22, wherein: The electrode terminal of the battery cell includes the second metal part, the adapter of the battery cell includes the first metal part, and the adapter electrically connects the electrode terminal and the tab of the electrode assembly.

24. The battery cell according to claim 22, wherein: The electrode terminal of the battery cell includes the second metal member, the tab of the electrode assembly of the battery cell includes the first metal member, and the tab is welded to the electrode terminal. 25 . A battery comprising the welding component according to claim 1 or the battery cell according to claim 22 .

26. An electrical device comprising the battery according to claim 25, wherein the battery is used to provide electrical energy.

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