Structural member and preparation method therefor, battery cell, battery, and electrical device

Abstract

A structural member (1) and a preparation method therefor, a battery cell (10), a battery (100), and an electrical device. The structural member (1) is provided with a welding area (11) for welding with a target member (2). The welding area (11) comprises a first portion (111) and a second portion (112). The second portion (112) has a weaker capability to receive welding energy compared to the first portion (111), and the capability to receive welding energy refers to the depth of weld penetration formed at the welding location.

Description

Structural component and preparation method thereof, battery cell, battery and electrical equipment

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application (202310871172.5) filed on July 17, 2023, entitled “Structural parts and preparation methods thereof, battery cells, batteries and electrical equipment”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to the field of battery technology, and in particular to a structural part, a battery cell, a battery, an electrical device, a method for judging the welding quality of a structural part and a target part, and a method for preparing the structural part. Background Art

[0004] With the popularization and promotion of new energy vehicles, the charging and discharging performance and endurance of new energy vehicles are attracting increasing attention and attention. As a rechargeable battery, power batteries are the power source of new energy vehicles and are widely used in the field of new energy vehicles.

[0005] The battery manufacturing process involves welding between components, and the components are prone to deformation and cracking during welding.

[0006] Summary of the Invention

[0007] The embodiments of the present application provide a structural part for penetration welding and a preparation method thereof, a battery cell, a battery and an electrical device. When the structural part is used for welding with a target part, the structural part is not easily deformed or cracked, and the welded product has a high welding quality.

[0008] In a first aspect, an embodiment of the present application provides a structural part for penetration welding, the structural part having a welding area for welding to a target part, the welding area including a first part and a second part, wherein the ability of the second part to receive welding energy is weaker than the ability of the first part to receive welding energy, wherein the ability to receive welding energy refers to the depth of penetration formed at the weld.

[0009] In the above technical solution, the structural part has a welding area, and the welding area includes a first part and a second part. The energy of the second part receiving welding energy is weaker than the ability of the first part to receive welding energy. With such an arrangement, the second part can be used to preheat the first part, and the first part can achieve effective welding. The welding of the structural part and the target part is not easy to deform and has higher welding quality.

[0010] In addition, the above-mentioned structural parts can also serve as an intermediate product. This intermediate product, which is between the raw materials and the standard products, can reduce the difficulty of preparing the standard products and facilitate the preparation of standard products with the performance of identifying the welding quality by color in appearance.

[0011] In some embodiments, the first portion has a first surface for receiving welding energy, and the second portion protrudes from the first surface.

[0012] In the above technical solution, by increasing the thickness of the first portion, the second portion's ability to receive welding energy is weakened. Thus, when positive defocus welding is employed and the welding equipment provides the same welding energy, the surface of the second portion that receives the welding energy is closer to the laser source than the first surface. The area of ​​the light spot formed on the second surface is larger than that formed on the first surface. The welding energy per unit area of ​​the second portion's surface that receives the welding energy is lower than that per unit area of ​​the first surface. Consequently, the second weld mark formed on the second portion has a smaller penetration depth than the first weld mark formed on the first portion.

[0013] In addition, increasing the thickness of the second part weakens the second part's ability to receive welding energy, and the first part and the second part can be made of the same material, which further reduces the difficulty of preparation, facilitates production, and improves the production efficiency of structural parts.

[0014] In some embodiments, the first portion has a first surface for receiving welding energy, the second portion includes a second surface for receiving welding energy, and the roughness of the first surface is greater than the roughness of the second surface.

[0015] In the above technical solution, the roughness of the first surface is greater than the roughness of the second surface, so that the ability of the second part to receive welding energy is weaker than that of the first part.

[0016] In some embodiments, the second portion protrudes from the first surface.

[0017] In the above technical solution, the structural member is adjusted by increasing the thickness of the second portion and changing the roughness of the second portion, which facilitates production and manufacturing. At the same time, the structural member is also suitable for products that require roughness.

[0018] In some embodiments, the first portion has a first surface for receiving welding energy, the second portion has a second surface for receiving welding energy, the area of ​​the first surface is S1, the area of ​​the second surface is S2, and 0.1≤S2 / S1≤0.4.

[0019] In the above technical solution, the proportion of the second surface in the entire welding area can be controlled within a certain range, so that the second part can be used to identify the welding quality after welding and has little effect on the connection stability between the structural part and the target part.

[0020] In some embodiments, the first portion has a greater absorption rate of welding energy than the second portion.

[0021] In the above technical solution, the absorption rate of the first part to welding energy is made greater than that of the second part, so that the ability of the second part to receive welding energy is weaker than that of the first part.

[0022] In some embodiments, the material of the first portion includes at least one of steel, aluminum, nickel, and copper.

[0023] In the above technical solution, the materials are easy to obtain and the production is convenient.

[0024] In some embodiments, the material of the second portion includes one of copper and aluminum.

[0025] In the above technical solution, the materials are easy to obtain and the production is convenient.

[0026] In some embodiments, the first portion is disposed around the outer periphery of the second portion.

[0027] In the above technical solution, the first part is arranged around the outer periphery of the second part, which is convenient for production and manufacturing. The first part and the second part also occupy less area, reducing the size occupied by the structural parts.

[0028] In a second aspect, an embodiment of the present application provides a battery cell, the battery comprising a target part and a structural part provided by any of the above embodiments; the target part is welded to the structural part.

[0029] In some embodiments, a battery cell includes an electrode terminal, a tab, and a current collecting member, wherein the current collecting member is used to connect the electrode terminal to the tab, and any two of the electrode terminal, the current collecting member, and the tab are the target component and the structural component, respectively.

[0030] In a third aspect, an embodiment of the present application provides a battery, comprising a battery cell provided by any embodiment of the second aspect.

[0031] In a fourth aspect, an embodiment of the present application further provides a battery, comprising a plurality of battery cells and the structural member provided by the above embodiment, wherein the battery cells have electrode terminals; the structural member is welded to the electrode terminals to achieve electrical connection of the plurality of battery cells.

[0032] In a fifth aspect, an embodiment of the present application provides an electrical device, which includes the battery cell provided by the above embodiment, and / or the electrical device protects the battery provided by the above embodiment, and the battery cell or the battery is used to provide electrical energy.

[0033] In a sixth aspect, an embodiment of the present application provides a method for judging the welding quality of a structural part and a target part, wherein the structural part has a welding area for welding with the target part, and the welding area includes a first part and a second part, wherein the ability of the second part to receive welding energy is weaker than the ability of the first part to receive welding energy, wherein the ability to receive welding energy refers to the depth of penetration formed at the weld, and the structural part and the target part are welded in the first part and the second part by a first welding energy value to form a first weld mark in the first part and a second weld mark in the second part. If the color of the second weld mark is a predetermined color, the penetration of the first weld mark is less than or equal to the thickness of the first part.

[0034] In the above technical solution, the method for judging the welding quality of the structural part and the target part can judge the welding quality by whether a predetermined color appears in appearance. The judgment method is simple and has high effect.

[0035] In a seventh aspect, an embodiment of the present application provides a method for preparing a structural member for penetration welding, comprising:

[0036] providing a structural member having a welding region for welding to a target member;

[0037] A first portion and a second portion are formed in the welding region, and the second portion has a weaker ability to receive welding energy than the first portion.

[0038] In the above technical solution, the structural part and the target part obtained by the preparation method can have high welding quality, and the structural part is not easily deformed during welding. The structural part 1 can also serve as an intermediate product, which can reduce the manufacturing difficulty of standard products such as those whose welding quality can be identified by appearance.

[0039] In some embodiments, the preparation method further includes: welding the structural component to the target component using a first welding energy value, forming a first weld mark on the first portion, wherein the penetration of the first weld mark is greater than the thickness of the first portion; gradually reducing the welding energy value until the penetration of the first weld mark is equal to the thickness of the first portion; when the penetration of the first weld mark is equal to the thickness of the first portion, the welding energy value is a second energy; if the second weld mark is formed on the second portion using the second welding energy value, and the color of the second weld mark just reaches a predetermined color, the preparation of the structural component is completed;

[0040] If the color of the second weld mark does not reach the predetermined color when the second weld energy value is used to weld the second part to form the second weld mark, the ability of the second part to receive welding energy is adjusted until the color of the second weld mark reaches the predetermined color when the second part is welded using the second welding energy value, and the preparation of the structural part is completed.

[0041] In the above technical solution, the above steps can be used to prepare the intermediate product into a standard product, and the standard product can be used to judge the welding quality based on the appearance, thereby improving production efficiency.

[0042] In some embodiments, the method of adjusting the ability of the second portion to receive welding energy includes at least one of changing a thickness of the second portion, changing a laser absorptivity of the second portion, and changing a roughness of the second portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] 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. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0044] FIG1 is a schematic structural diagram of a vehicle according to some embodiments of the present application;

[0045] FIG2 is a schematic diagram of the exploded structure of a battery according to some embodiments of the present application;

[0046] FIG3 is a schematic diagram of the exploded structure of a battery cell according to some embodiments of the present application;

[0047] FIG4 is a schematic diagram of the exploded structure of battery cells according to other embodiments of the present application;

[0048] FIG5 is a schematic diagram of structural members according to some embodiments of the present application;

[0049] FIG6 is a schematic diagram of structural members according to some other embodiments of the present application;

[0050] FIG7 is a partial cross-sectional view of welding of a structural component and a target component according to some embodiments of the present application;

[0051] FIG8 is a partial cross-sectional view of a cold weld between a structural component and a target component according to some embodiments of the present application;

[0052] FIG9 is a schematic diagram of forming a weld mark by welding in a welding area according to some embodiments of the present application;

[0053] FIG10 is a schematic structural diagram of batteries according to some other embodiments of the present application;

[0054] FIG11 is a flow chart of a method for determining welding quality of a structural component and a target component according to some embodiments of the present application;

[0055] FIG12 is a flow chart of a method for manufacturing a structural member according to some embodiments of the present application;

[0056] FIG13 is a flow chart of a method for manufacturing a structural member according to yet other embodiments of the present application.

[0057] Icon: 1000-vehicle; 100-battery; 200-motor; 300-controller; 20-housing; 21-first sub-housing; 22-second sub-housing; 23-accommodation space; 10-battery cell; 12-housing; 13-electrode assembly; 14-end cover; 15-electrode terminal; 16-current collecting member; 1-structural part; 11-welding area; 111-first part; 1111-first surface; 111a-first weld mark; 112-second part; 1121-second surface; 112a-second weld mark; 2-target part. 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] In the description of this application, it should be noted that, unless otherwise specified, "multiple" means more than two; the terms "upper", "lower", "left", "right", "inside", "outside", etc., indicating directions or positional relationships, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on this application. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" is not strictly perpendicular, but is within the allowable error range. "Parallel" is not strictly parallel, but is within the allowable error range.

[0063] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0064] 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.

[0065] The term "plurality" used in this application refers to two or more (including two).

[0066] In this application, battery cells include but are not limited to lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries. The shapes of battery cells include but are not limited to cylinders, flat bodies, rectangular parallelepipeds, or other shapes. Battery cell packaging includes but is not limited to cylindrical battery cells, prismatic battery cells, and soft-pack battery cells.

[0067] The battery referred to in the embodiments of this application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in this application may include a battery module or a battery pack. A battery generally includes a casing for enclosing one or more battery cells. The casing can reduce the possibility of liquid or other foreign matter outside the casing approaching the battery cells and affecting the charging or discharging of the battery cells.

[0068] A battery cell includes an electrode assembly and an electrolyte. The electrode assembly consists of a positive electrode sheet, a negative electrode sheet, and a separator. A battery cell primarily operates by the movement of metal ions between the positive and negative electrode sheets. The positive electrode sheet includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive electrode collector. The uncoated positive electrode collector protrudes from the coated positive electrode collector, and the uncoated positive electrode collector serves as the positive electrode tab. For lithium-ion batteries, for example, the positive electrode current collector can be made of aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide. The negative electrode sheet includes a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative electrode collector. The uncoated negative electrode collector protrudes from the coated negative electrode collector, and the uncoated negative electrode collector serves as the negative electrode tab. The negative electrode current collector can be made of copper, and the negative electrode active material can be carbon or silicon, among others. To ensure that high currents can pass without fusing, multiple positive electrode tabs are stacked together, and multiple negative electrode tabs are stacked together. The separator can be made of materials such as PP (polypropylene) or PE (polyethylene). Furthermore, the electrode assembly can be a wound or laminated structure, but the embodiments of the present application are not limited thereto.

[0069] For general battery cells, in order to facilitate the electrical connection between the electrode tabs of the electrode assembly and the end caps, an adapter plate (also known as a current collecting plate in cylindrical batteries, hereinafter referred to as a current collecting component) is usually provided in the shell. The current collecting component is connected to the electrode terminal and the electrode tab of the electrode assembly (the tab is a full tab, which is connected to the current collecting plate after being flattened) to achieve electrical connection between the electrode assembly and the electrode terminal.

[0070] During the production and preparation of battery cells, the current collecting components and electrode terminals are usually welded by penetration welding. In the penetration welding process, the materials to be welded need to be stacked and divided into upper layer materials (such as the current collecting components on the top) and lower layer materials (such as the electrode terminals on the bottom). The upper layer material is heated and welded from the surface to connect the upper layer material with the lower layer material.

[0071] In penetration welding, sufficient welding energy is required for effective welding. This energy is typically high. Direct welding can cause the upper material to be heated suddenly, leading to rapid temperature increases in the weld zone and resulting in deformation, cracking, and other quality issues. Directly reducing the welding energy can result in cold welds, impacting weld quality.

[0072] In view of this, an embodiment of the present application provides a structural component for penetration welding, wherein the structural component has a welding region for welding to a target component, and the welding region includes a first portion and a second portion, wherein the second portion has a weaker ability to receive welding energy than the first portion. The second portion acts as a preheating device for the first portion. When the second portion receives welding energy, the second portion heats up more slowly. After heating up, the second portion transfers heat to the first portion, causing the first portion to slowly heat up to a certain initial temperature. When welding to the first portion, the first portion maintains a certain initial temperature, which helps alleviate quality issues such as deformation and cracking of the upper layer material caused by rapid heating in the welding region.

[0073] The structural parts described in the embodiments of the present application are suitable for battery cells, batteries, electrical equipment using batteries or battery cells, power supply systems using battery cells or batteries, and other components used for penetration welding.

[0074] The battery cells and batteries disclosed in the embodiments of the present application can be applied to, but not limited to, electrical equipment such as vehicles, ships, or aircraft.

[0075] The embodiments of the present application provide an electrical device that uses a battery as a power source. The electrical device may be, but is not limited to, a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, and the like. The vehicle may be a fuel vehicle, a gas vehicle, or a new energy vehicle. The new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle. The spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft. The electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy. The electric tool may include a metal cutting power tool, a grinding power tool, an assembly power tool, and a railway power tool, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator, and an electric planer.

[0076] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle 1000 as an example.

[0077] Please refer to FIG1 , which is a schematic diagram of the structure of a vehicle 1000 according to some embodiments of the present application. A battery 100 is disposed inside the vehicle 1000 . The battery 100 can be disposed at the bottom, head, or tail of the vehicle 1000 . The battery 100 can be used to power the vehicle 1000 . For example, the battery 100 can serve as an operating power source for the vehicle 1000 .

[0078] The vehicle 1000 may further include a controller 300 and a motor 200 . The controller 300 is used to control the battery 100 to supply power to the motor 200 , for example, to meet the power requirements of the vehicle 1000 during startup, navigation, and driving.

[0079] In some embodiments of the present application, the battery 100 can not only serve as the operating power source of the vehicle 1000, but also serve as the driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0080] In some embodiments, please refer to FIG. 2 , which is a schematic diagram of the exploded structure of a battery 100 according to some embodiments of the present application. The battery 100 includes a plurality of battery cells 10. The plurality of battery cells 10 may be connected in series, in parallel, or in a hybrid connection. The term "hybrid connection" refers to the connection of the plurality of battery cells 10 in both series and parallel.

[0081] In some embodiments, the battery 100 may further include a busbar component (not shown in FIG. 2 ), and the multiple battery cells 10 may be electrically connected via the busbar component to achieve series connection, parallel connection, or hybrid connection of the multiple battery cells 10 .

[0082] The busbar component may be a metal conductor, such as copper, iron, aluminum, steel, aluminum alloy, etc.

[0083] In some embodiments, the battery 100 may further include a housing 20 for accommodating the battery cells 10. The housing 20 may include a first sub-housing 21 and a second sub-housing 22, which cover each other to define a storage space 23 for accommodating the battery cells 10. The connection between the first sub-housing 21 and the second sub-housing 22 may be sealed by a sealing element (not shown), such as a sealing ring or sealant.

[0084] The first sub-box 21 and the second sub-box 22 can have various shapes, such as a rectangular parallelepiped, a cylinder, etc. The first sub-box 21 can be a hollow structure with one side open, and the second sub-box 22 can also be a hollow structure with one side open. The open side of the second sub-box 22 covers the open side of the first sub-box 21, thereby forming the box 20 with the storage space 23. Of course, the first sub-box 21 can also be a hollow structure with one side open, and the second sub-box 22 can be a plate-like structure. The second sub-box 22 covers the open side of the first sub-box 21, thereby forming the box 20 with the storage space 23.

[0085] Please refer to Figures 3 and 4. Figure 3 is a schematic diagram of the exploded structure of a battery cell 10 provided in some embodiments of the present application, and Figure 4 is a schematic diagram of the exploded structure of a battery cell 10 provided in other embodiments of the present application. A battery cell 10 is the smallest unit that makes up a battery 100. A battery cell 10 may include a housing 12, an electrode assembly 13, a current collecting member 16, and an end cap 14. Functional components such as electrode terminals 15 may be provided on the end cap 14. The electrode terminals 15 are electrically connected to the tabs via the current collecting member 16. The housing 12 is used to house the electrode assembly 13. The housing 12 may be a hollow structure with an opening at one end or a hollow structure with openings at both ends. The housing 12 may be made of a variety of materials, such as copper, iron, aluminum, steel, and aluminum alloys. The housing 12 may have a variety of shapes, such as a cylinder or a rectangular parallelepiped. For example, in Figure 3, the housing 12 is a rectangular parallelepiped.

[0086] The end cap 14 is a component that covers the opening of the shell 12 to isolate the internal environment of the battery cell 10 from the external environment. The end cap 14 covers the opening of the shell 12, and the end cap 14 and the shell 12 together define a sealed space for accommodating the electrode assembly 13, electrolyte and other functional components. The shape of the end cap 14 can be adapted to the shape of the shell 12. As shown in Figure 3, the shell 12 is a rectangular parallelepiped structure, and the end cap 14 is a rectangular plate structure adapted to the shell 12. As shown in Figure 4, the shell 12 is a cylindrical structure, and the end cap 14 is a circular plate structure adapted to the shell 12. The material of the end cap 14 can also be various. For example, the end cap 14 can be a metal material, such as copper, iron, aluminum, steel, aluminum alloy, etc. The material of the end cap 14 can be the same as or different from the material of the shell 12.

[0087] In the battery cell 10, there can be one or two end caps 14. If the housing 12 is a hollow structure with an opening at one end, one end cap 14 is provided. If the housing 12 is a hollow structure with openings at both ends, two end caps 14 are provided, one covering each opening of the housing 12.

[0088] Referring to Figures 5 to 9, Figure 5 is a structural schematic diagram of the structural member 1 provided in some embodiments of the present application; Figure 6 is a structural schematic diagram of the structural member 1 provided in some other embodiments of the present application; Figure 7 is a partial cross-sectional view of the welding of the structural member 1 and the target member 2 in some embodiments of the present application; Figure 8 is a partial cross-sectional view of the cold weld of the structural member 1 and the target member 2 in some embodiments of the present application; Figure 9 is a schematic diagram of the formation of a weld mark by welding in the welding area 11 in some embodiments of the present application.

[0089] An embodiment of the present application provides a structural component 1 for penetration welding, wherein the structural component 1 has a welding area 11 welded to a target component 2, and the welding area 11 includes a first portion 111 and a second portion 112, wherein the ability of the second portion 112 to receive welding energy is weaker than the ability of the first portion 111 to receive welding energy, wherein the ability to receive welding energy refers to the depth of penetration formed at the weld.

[0090] Penetration welding includes arc welding, laser welding, etc. During penetration welding, the target part 2 and the structural part 1 are stacked together, and the energy source forms a small hole on the surface of the structural part 1 and penetrates the structural part 1, fusing the structural part 1 and the target part 2 together, forming a weld mark at the weld.

[0091] The component to be welded to structural component 1 is target component 2. Structural component 1 can be any component to be welded to target component 2. In other words, the structural component 1 provided in this embodiment can be used in any structure involving welding two components. For example, structural component 1 can serve as the housing 12, electrode terminal 15, busbar, current collecting member 16, and so on of a battery cell 10.

[0092] The area of ​​the structural component 1 used for welding with the target component 2 is the welding area 11 . The welding area can be a part of the structural component 1 (as shown in FIG. 5 ). Of course, the structural component 1 can also be entirely weldable.

[0093] The shape of the structural member 1 can be various, such as rectangular, circular, polygonal, elliptical, etc. The shape of the welding area 11 can also be various, such as regular rectangular, circular, polygonal, elliptical, etc. Of course, the shape of the welding area 11 can also be irregular.

[0094] The first part 111 and the second part 112 are both weldable welding areas 11. The energy actually received by the welding area 11 and the welding energy actually provided by the welding equipment are different concepts. The welding energy actually received by the welding area 11 will be less than the welding energy actually provided by the welding equipment. The ability of the welding area 11 to receive welding energy is the main factor affecting the welding energy actually received by the welding area 11. The penetration depth can reflect the ability of the welding area to receive welding energy. Specifically, when the same welding energy is provided for welding, the stronger the ability to receive welding energy, the deeper the penetration depth of the weld mark formed at the weld, and the weaker the ability to receive welding energy, the shallower the penetration depth of the weld mark formed at the weld. Sufficient penetration depth can achieve penetration welding (as shown in Figure 7). When the penetration depth is less than the thickness of the welding position, it means that the structural part 1 has not been welded through, there is a cold weld or the welding quality is not high (as shown in Figure 8).

[0095] The ability of the second portion 112 to receive welding energy is weaker than that of the first portion 111 , that is, when the same welding energy is provided, the penetration formed by welding in the second portion 112 is smaller than the penetration formed by welding in the first portion 112 .

[0096] Penetration refers to the distance between the deepest point of melting in the weld and the surface of the weld location, i.e., the depth of the weld mark. Specifically, referring to FIG9 , a schematic diagram of forming a weld mark during welding in welding region 11 according to some embodiments of the present application is shown. The first portion 111 has a first surface 1111 that receives welding energy, and the second portion 112 has a second surface 1121 that receives welding energy. Welding on the first surface 1111 forms a first weld mark 111a, and welding on the second surface 1121 forms a second weld mark 112a. The distance from the deepest point of the first weld mark 111a to the first surface 1111 is the penetration of the first weld mark 111a, and the distance from the deepest point of the second weld mark 112a to the second surface 1121 is the penetration of the first weld mark 111a. It should be noted that the distance that the first weld mark 111a extends beyond the first surface 1111 and the distance that the second weld mark 112a extends beyond the second surface 1121 are both very small, and the effect of the weld marks on the thickness of the first portion 111 and the second portion 112 can be ignored.

[0097] If only the first portion 111 is welded directly on the first portion 111, the penetration formed in the first portion 111 will be deeper, and the first portion 111 can have higher welding quality, but the rapid heating of the structural component 1 will easily cause deformation and cracking. If the welding energy is directly reduced, although the risk of deformation and cracking of the structural component 1 is reduced, the first portion 111 has a weaker ability to receive welding energy, resulting in shallower penetration formed in the first portion 111, affecting the welding quality.

[0098] Therefore, the energy that the second portion 112 receives from welding is weaker than that of the first portion 111. When the structural component 1 is connected to the target component 2, the second portion 112 is welded first, and then the first portion 111. Because the second portion 112 is less capable of receiving welding energy than the first portion 111 and heats up more slowly, the structural component 1 is less likely to deform when the second portion 112 is welded. Moreover, due to the effect of heat transfer, the first portion 111 can reach a certain initial temperature. In this way, when the first portion is welded, the rapid temperature rise is alleviated, thereby reducing the risk of deformation and cracking of the structural component 1.

[0099] In this embodiment, the energy of the second part 112 receiving welding energy is weaker than the ability of the first part 111 to receive welding energy. With such an arrangement, the second part 112 can be used to preheat the first part 111, and the first part 111 can achieve effective welding. The welding of the structural part 1 and the target part 2 is not easy to deform and has a higher welding quality.

[0100] In addition to the aforementioned technical effects, the structural component 1 provided in this embodiment can also serve as an intermediate product, intermediate between the raw material and the standard product. A standard product is a product whose welding quality can be identified by its color. This structural component 1 helps reduce the difficulty of preparing the standard product.

[0101] Specifically, in the penetration welding process, the stability of the welding energy provided is insufficient, and the phenomenon of cold welding is prone to occur. For example, the cold welding between the current collecting component 16 and the pole will affect the flow of current and the stability of the electrical connection. Cold welding will cause the contact resistance between the current collecting component 16 and the pole ear of the electrode assembly 13 to be large, resulting in a high charge and discharge rate of the battery cell 10, which is not conducive to improving the performance of the battery cell 10. On the other hand, during use, local overcurrent is prone to occur between the adapter and the pole ear of the electrode assembly 13, and the battery cell 10 is at risk of internal temperature rise, which is not conducive to improving the safety of the battery cell. Therefore, cold welding seriously threatens the reliability of the battery cell. During the production process, it is necessary to promptly detect and eliminate the battery cell 10 with cold welding to avoid it flowing into the next process and causing hidden dangers.

[0102] In the penetration welding process, the materials to be welded need to be stacked and divided into upper and lower materials. Since the penetration welding weld is on the surface of the upper material and has a certain thickness, the input welding energy changes will affect the depth of penetration (the higher the welding energy density, the deeper the penetration, and the lower the welding energy density, the shallower the penetration). When the welding energy provided by the welding equipment is insufficient, or the welding energy is affected by external factors, resulting in a decrease in the welding energy of the upper material and insufficient penetration, the upper material is not connected to the lower material, which is a cold weld. Cold welds cannot be simply identified from the appearance. The detection of welding quality in related technologies requires auxiliary detection instruments and the detection methods are complex, time-consuming, and inefficient.

[0103] Therefore, it is necessary to provide a structural part that can identify cold welds on the outside and simplify the cold weld identification process.

[0104] In some other related welding technologies, the characteristic of penetration welding is that the penetration depth of the weld mark formed after welding will correspond to different colors at different stages (the color of the weld mark usually changes in steps). Taking the adapter as copper material as an example, after penetration welding, when the penetration depth of the weld mark exceeds 0.4mm, the weld mark will appear bright white, and when the penetration depth of the weld mark is less than 0.4mm, the weld mark will appear dark purple. 0.4mm is the critical point for color change in the weld mark stage. The dark purple color can be used as a predetermined color as a basis for judging whether there is a cold weld. Therefore, using the above-mentioned color change characteristics to prepare a structural part that can identify cold welds in appearance has become a research direction.

[0105] However, the depth of weld penetration is affected by the weld surface's ability to absorb weld energy, which in turn is influenced by numerous factors, such as roughness, weld energy absorption capacity, and thickness. For these reasons, the critical point at which discoloration occurs is unknown for different components. Therefore, it's impossible to directly produce a standard product from raw materials to a specific specification, visually identifying any weld defects. This makes the production of standard products difficult. Therefore, reducing this difficulty remains a challenge.

[0106] The structural component 1 provided in this embodiment can be used as an intermediate product. By preparing this intermediate product, it is convenient to further adjust the ability of the second part 112 to receive welding energy based on the intermediate product (the specific adjustment method is mentioned later), until, when the same welding energy is used to weld the first part 111 and the second part 112, the penetration depth of the weld mark formed by the first part 111 is equal to the thickness of the first part 111, and the penetration depth of the weld mark formed by the second part 112 is at the critical point of stage discoloration. In this way, the second part 112 can be used to identify cold welds and welding quality after welding, and the first part 111 is used to achieve reliable welding with the target part 2, resulting in a structural component 1 (standard product) whose welding quality can be identified by appearance. Therefore, this structural component 1 reduces the difficulty of preparing standard products to a certain extent.

[0107] Structural component 1 in a standard product state is welded to target component 2. Since structural component 1 in a standard product state already has the characteristic that "when welded using the same welding energy, the penetration of the weld mark formed by second portion 112 is at the critical point of stage discoloration, and the welding energy can just penetrate structural component 1," the weld mark will appear in a first color and a second color when the penetration is on either side of the critical point. For example, if the penetration corresponding to the first color is less than the penetration corresponding to the second color, after the standard product is welded to target component 2, if the first color appears in second portion 112, it can be concluded that the penetration of first weld mark 111a is less than the thickness of first portion 111, first portion 111 is poorly welded, and the welding quality is insufficient.

[0108] The judgment principle is: when the welding energy is sufficient, the penetration of the first weld mark 111a will be greater than the thickness of the first part 111, and the color of the second weld mark 112a will exceed the critical point and present a second color. The second color indicates that the structural component 1 and the target component 2 are well welded in the first part 111.

[0109] When the welding energy is affected by external conditions and the provided welding energy is insufficient, the penetration of the first weld mark 111a is lower than the thickness of the first part 111 (cold weld or poor welding quality). The penetration of the second weld mark 112a will also decrease, and the degree of decrease is greater than the penetration of the first weld mark 111a. The color of the second weld mark 112a will break through the critical point and present the first color. The appearance of the first color represents that there is a cold weld between the structural component 1 and the target component 2 in the first part 111. The first color is used as the predetermined color for judging the welding quality. The weld mark of the second part 112 presents the predetermined color. It can be inferred that the weld mark formed on the first part 111 is lower than the thickness of the first part 111, that is, there is a cold weld or poor welding quality.

[0110] Based on the above principles, the structural component 1 provided in the embodiment of the present application can be used as an intermediate product to facilitate the preparation of a standard product, and the standard product can identify the welding quality from the appearance, thereby improving production efficiency.

[0111] Some embodiments are provided below, so that the ability of the second portion 112 to receive welding energy is weaker than that of the first portion 111 .

[0112] 7 , in some embodiments, the first portion 111 has a first surface 1111 for receiving welding energy, and the second portion 112 protrudes from the first surface 1111 .

[0113] When the target component 2 and the structural component 1 are stacked, the surface of the first portion 111 facing away from the target component 2 is the first surface 1111. First surface 1111 is used to receive welding energy, and the first weld mark 111a is formed on first surface 1111. Accordingly, the second portion 112 has a second surface 1121 that receives welding energy. Second surface 1121 is related to the ability of the second portion 112 to receive welding energy.

[0114] The second portion 112 may partially protrude from the first surface 1111 , or may be entirely protruding from the first surface 1111 . The thickness of the second portion 112 is greater than that of the first portion 111 .

[0115] Due to the characteristics of laser welding, laser welding generally requires a certain amount of defocus. The defocus amount affects the size of the laser spot. The larger the area of ​​the spot formed in the welding area 11, the lower the welding energy per unit area of ​​the welding area 11.

[0116] For positive defocus, the closer the surface of the second portion 112 receiving the welding energy is to the laser source, the larger the spot area formed on the surface, the lower the welding energy per unit area of ​​the surface, and thus the lower the received energy.

[0117] In the above embodiment, the ability of the second portion 112 to receive welding energy is reduced by increasing the thickness of the second portion 112. Thus, when positive defocus welding is employed and the welding equipment provides the same welding energy, the surface of the second portion 112 that receives the welding energy is closer to the laser source than the first surface 1111. The area of ​​the light spot formed on the second surface 1121 is larger than that formed on the first surface 1111. The welding energy per unit area of ​​the surface of the second portion 112 that receives the welding energy is lower than the welding energy per unit area of ​​the first surface 1111. The penetration depth of the second weld mark 112a formed on the second portion 112 is less than the penetration depth of the first weld mark 111a formed on the first portion 111.

[0118] By increasing the thickness of the second part 112 , the ability of the second part 112 to receive welding energy is weakened. The first part 111 and the second part 112 can be made of the same material, which further reduces the difficulty of preparation, facilitates production, and improves the production efficiency of the structural part 1.

[0119] In other embodiments, the second portion 112 may also be a groove. During welding, the second surface 1121 is farther away from the laser source than the first surface 1111. The structural member 1 of this embodiment is suitable for laser welding using a positive defocus method. When using negative defocus welding, the farther the second surface 1121 is from the laser source, the larger the area of ​​the light spot acting on the welding area 11, and the lower the welding energy corresponding to the unit area of ​​the second surface 1121. In this embodiment, a groove is used to weaken the ability of the second surface 1121 to receive welding energy, which is suitable for positive defocus welding.

[0120] The first portion has a first surface 1111 for receiving welding energy, and the second portion 112 includes a second surface 1121 for receiving welding energy. The roughness of the first surface 1111 is greater than that of the second surface 1121 .

[0121] It can be understood that the second surface 1121 is smoother than the first surface 1111 , and the first surface 1111 is rougher than the second surface 1121 .

[0122] When the first portion 111 and the second portion 112 are made of the same material, the first surface 1111 may be indented or laser treated to change its roughness, while the second surface 1121 remains untreated. Alternatively, both the first surface 1111 and the second surface 1121 may be roughened, with the first surface 1111 being roughened more severely.

[0123] Generally, when using the same power welding energy for penetration welding, the greater the roughness of the workpiece to be welded, the deeper the weld penetration will be. The smaller the roughness of the workpiece to be welded, the smaller its ability to receive welding energy will be, and the shallower the weld penetration will be.

[0124] Therefore, in the above embodiment, by making the roughness of the first surface 1111 greater than the roughness of the second surface 1121 , the ability of the second portion 112 to receive welding energy is weaker than that of the first portion 111 .

[0125] In some embodiments, the second portion protrudes from the first surface 1111 , and the roughness of the first surface 1111 is greater than the roughness of the second surface 1121 .

[0126] In this embodiment, the structural member 1 is adjusted by increasing the thickness of the second portion and changing the roughness of the second portion 112, which facilitates production and manufacturing. At the same time, the structural member 1 is also suitable for products that require roughness.

[0127] In some embodiments, the first portion has a first surface 1111 for receiving welding energy, and the second portion 112 has a second surface 1121 for receiving welding energy. The area of ​​the first surface 1111 is S1, the area of ​​the second surface 1121 is S2, and 0.1≤S2 / S1≤0.4.

[0128] Given a given total area of ​​weld region 11, the larger the area of ​​second surface 1121, the smaller the area of ​​first surface 1111. Because the weld mark formed by second portion 112 has a shallower penetration, second portion 112 serves to identify weld quality after welding, and thus can affect the stability of the connection between structural component 1 and target component 2. Therefore, 0.1 ≤ S2 / S1 ≤ 0.4 allows the proportion of second surface 1121 in the entire weld region 11 to be controlled within a certain range. This allows second portion 112 to be used for post-weld weld quality identification while minimizing its impact on the stability of the connection between structural component 1 and target component 2.

[0129] In some embodiments, the first portion has a greater absorption rate of welding energy than the second portion 112 .

[0130] The higher the absorption rate of the welding energy in the welding area 11 is, the easier it is for the welding energy to be absorbed by the surface receiving the welding energy, the faster the surface temperature rises, and the deeper the penetration formed by the melting of the material.

[0131] Different materials have different absorption rates for welding energy. Taking steel, aluminum and copper as examples, the laser absorption rate of steel is greater than that of aluminum and greater than that of copper.

[0132] In the above embodiment, the absorption rate of the first part 111 to welding energy is greater than that of the second part 112 , so that the ability of the second part 112 to receive welding energy is weaker than that of the first part 111 .

[0133] Furthermore, the material of the first part includes at least one of steel, aluminum, nickel, and copper.

[0134] For example, if the material of the first part 111 is steel, the second part 112 is selected from a material with a lower absorption rate of welding energy than steel, such as aluminum, copper or other materials; if the material of the first part 111 is aluminum, the second part 112 is selected from a material with a lower absorption rate of welding energy than aluminum, such as copper or other materials.

[0135] Of course, the first portion 111 or the second portion 112 can be plated with corresponding materials to change the absorption rate of welding energy. For example, the first portion 111 is plated with nickel-copper alloy to form the first surface 1111, and the second portion 112 is untreated pure copper.

[0136] Of course, the first portion 111 and the second portion 112 may also be made of an alloy material, as long as the absorption rate of the second portion 112 to the welding energy is lower than the absorption rate of the first portion 111 to the welding energy.

[0137] In the above embodiments, the materials are easy to obtain and the production is convenient.

[0138] In some embodiments, the material of the second portion includes one of copper and aluminum.

[0139] It should be understood that when the second portion 112 is made of copper, the first portion 111 should be made of a material with a higher absorption rate for welding energy than copper. When the second portion 112 is made of aluminum, the first portion 111 should be made of a material with a higher absorption rate for welding energy than aluminum.

[0140] In the above embodiments, the materials are easy to obtain and the production is convenient.

[0141] In some embodiments, the first portion is disposed around the outer periphery of the second portion 112 .

[0142] The first portion 111 and the second portion 112 may be concentric circles, in which case the center of the first portion 111 coincides with the center of the second portion 112. Of course, the second portion 112 may also be offset relative to the first portion 111, in which case the center of the second portion 112 does not coincide with the center of the first portion 111.

[0143] The first portion 111 and the second portion 112 may also be concentric rings. In the radial direction, the first portion 111 and the second portion 112 are spaced apart. In this case, the first portion 111 is also arranged around the outer circumference of the second portion 112 .

[0144] Of course, in other embodiments, the first portion 111 can be spaced apart from the second portion 112 (as shown in FIG6 ). In this spaced arrangement, the first portion 111 is not arranged around the periphery of the second portion 112, and the first portion 111 and the second portion 112 exist independently. Of course, the first portion 111 and the second portion 112 can also be adjacent, that is, the first portion 111 is arranged next to the second portion 112.

[0145] The first portion 111 is arranged around the outer periphery of the second portion 112 to facilitate manufacturing. At the same time, the first portion 111 and the second portion 112 occupy less area, reducing the size occupied by the structural component 1.

[0146] In some embodiments, the present application provides a battery cell 10 , which includes a target part 2 and a structural part 1 for penetration welding provided in the above embodiment, wherein the target part 2 is welded to the structural part 1 .

[0147] 3 and 4 , in some embodiments, a battery cell 10 includes an electrode terminal 15, a tab, and a current collecting member 16. The current collecting member 16 is used to connect the electrode terminal 15 to the tab. Any two of the electrode terminal 15, the current collecting member 16, and the tab are the target component 2 and the structural component 1, respectively.

[0148] The electrode terminal 15 is usually provided on the end cap 14 of the battery cell 10 . The electrode terminal 15 is a component having one end connected to the tab of the electrode assembly 13 through the current collecting member 16 and the other end connected to the power user.

[0149] The current collecting member 16 can be a connecting piece in a prismatic battery cell 10 or a collecting plate in a cylindrical battery 100. During assembly of the battery cell 10, the collecting plate or connecting piece is usually used to connect the tabs of the electrode assembly 13 to the electrode terminals 15.

[0150] Exemplarily, the structural component 1 is the current collecting component 16 , and the target component 2 is the electrode tab; further exemplarily, the structural component 1 is the current collecting component 16 , and the target component 2 is the electrode terminal 15 .

[0151] The related art includes two types of battery cells 10. The first type is: two electrode terminals 15 are set on the outside of the shell 12 of the battery cell 10 as the output end of the current. The electrode terminals 15 are used to lead out the electrodes. The electrode terminals 15 include a positive electrode and a negative electrode. The positive electrode and the negative electrode are respectively connected to the positive electrode tab and the negative electrode tab of the electrode assembly 13 through an adapter plate or a current collecting plate. In the battery cell 10 of this structure, the current collecting plate or the adapter plate is welded to the tab. The second type is: in order to simplify the structure of the battery cell 10, the cover plate is used as the output end of the first electrode, and the first electrode is led out through the cover plate. The first electrode is a positive electrode or a negative electrode. The positive electrode or the negative electrode is directly connected to the positive electrode tab or the negative electrode tab of the electrode assembly 13. The shell 12 is used as the output end of the second electrode. The second electrode is led out through the shell 12. The first electrode is a negative electrode or a positive electrode. The shell 12 is directly electrically connected to the negative electrode tab or the positive electrode tab of the electrode.

[0152] Therefore, in some embodiments, for the battery cell 10 of the first structure described above, the structural member 1 can serve as the current collecting member 16 , and the structural member 1 can be used for penetration welding with the electrode terminal 15 to achieve electrical connection, and the structural member 1 can also be used for penetration welding with the tab to achieve electrical connection.

[0153] Of course, in other embodiments, for the battery cell 10 of the second structure described above, the structural member 1 can serve as the housing 12. In this case, the current collecting member 16 serves as the output terminal of the electrode, and the second electrode is led out through the structural member 1. The first electrode is a negative electrode or a positive electrode, and the structural member 1 is directly welded to the negative electrode tab or the positive electrode tab of the electrode. It should be understood that the structural member 1 can be any component that needs to be welded to the target part 2. In other words, the structural member 1 provided in this embodiment can be used in any structure involving welding two components. For example, the structural member 1 can serve as one of the tabs of the electrode assembly 13, the electrode terminal 15, the current collector, the current collecting member 16, and the housing 12 of the battery cell 10. For example, if the structural member 1 is a tab, the target part can be the electrode terminal 15.

[0154] The battery cell 10 using the above-mentioned structural member 1 has a higher production effect.

[0155] In some embodiments, the present application further provides a battery 100 , which includes the battery cell 10 provided in any of the above embodiments.

[0156] Refer to FIG. 10 , which is a schematic structural diagram of a battery 100 according to some other embodiments of the present application.

[0157] In some embodiments, the present application further provides a battery 100 , which includes the structural member 1 of any of the above embodiments and multiple battery cells 10 , each of which has an electrode terminal 15 , and the structural member 1 is welded to the electrode terminal 15 to achieve electrical connection between the multiple battery cells 10 .

[0158] Multiple means two or more (including two).

[0159] Optionally, the structural member 1 is a busbar, also known as a busbar, and multiple battery cells 10 can be connected in series or in parallel via the busbar to achieve high capacity requirements.

[0160] It should be noted that the battery cell 10 in this embodiment may also contain the structural member 1 provided in the above embodiment.

[0161] The battery 100 adopts the structural member 1 provided in the above embodiment, which reduces the difficulty of manufacturing the battery 100 to a certain extent, and provides an appearance to identify the welding quality of the tab and the electrode terminal 15.

[0162] In some embodiments, the present application also provides an electrical device, which includes the battery cell 10 provided in the above embodiment, and / or the electrical device includes the battery 100 provided in the above embodiment, and the battery cell 10 or the battery 100 is used to provide electrical energy for the vehicle 1000.

[0163] 11 , which is a flow chart of a method for determining welding quality between a structural component 1 and a target component 2 according to some embodiments of the present application.

[0164] An embodiment of the present application also provides a method for judging the welding quality of a structural component 1 and a target component 2, wherein the structural component 1 has a welding area 11 for welding with the target component 2, and the welding area 11 includes a first part 111 and a second part 112, wherein the ability of the second part 112 to receive welding energy is weaker than the ability of the first part 111 to receive welding energy, wherein the ability to receive welding energy refers to the depth of penetration formed at the weld, wherein the judgment method includes the steps: S10: welding the structural component 1 and the target component 2 in the first part 111 and the second part 112 using a first welding energy value to form a first weld mark 111a in the first part 111 and a second weld mark 112a in the second part 112; if the color of the second weld mark 112a is a predetermined color, the penetration of the first weld mark 111a is less than or equal to the thickness of the first part 111.

[0165] The predetermined color is pre-set based on the material properties of the second portion 112 and can be used to identify cold welds and assess welding quality. For example, when the second weld mark 112a has a high penetration depth, the copper appears bright white. When the second weld mark 112a has a shallow penetration depth, the second weld mark 112a appears dark purple, which can be used as the predetermined color. The color of the second weld mark 112a reaching the predetermined color means that the penetration depth of the second weld mark 112a is at the critical point where the weld mark changes color from bright white to dark purple.

[0166] If the color of the second weld mark 112a is the predetermined color, the penetration of the first weld mark 111a is less than or equal to the thickness of the first portion 111, and a cold weld exists, resulting in poor welding quality.

[0167] It should be understood that the above judgment method judges the welding quality of the structural component 1 and the target component 2 in the standard product state.

[0168] The method for judging the welding quality of the structural component 1 and the target component 2 provided in this embodiment can judge the welding quality by whether a predetermined color appears in appearance. The judgment method is simple and has high effect.

[0169] Referring to Figure 12 and in combination with Figure 9, Figure 12 is a flow chart of a method for preparing a structural part 1 in some embodiments of the present application; Figure 9 can represent the welding state of the structural part 1 and the target part 2 when the structural part 1 in the intermediate product state is adjusted, or the welding state of the structural part 1 and the target part 2 in the standard product state.

[0170] In some embodiments, the present application also provides a method for preparing a through-weld structural member 1 , comprising the following steps.

[0171] S100: Providing a structural member 1, wherein the structural member 1 has a welding area 11 for welding with a target member 2;

[0172] S200: A first portion 111 and a second portion 112 are formed in the welding area 11, and the ability of the second portion 112 to receive welding energy is weaker than that of the first portion 111.

[0173] Among them, the ability of the second part 112 to receive welding energy is weaker than the ability of the first part 111 to receive welding energy in the following ways: the second part 112 protrudes from the first surface 1111, the roughness of the first surface 1111 is greater than the roughness of the second surface 1121, or the absorption rate of the first surface 1111 to welding energy is greater than the absorption rate of the second surface 1121 to welding energy.

[0174] It should be understood that the preparation method provided in this embodiment can achieve high-quality welding between the structural component 1 and the target component, and the structural component is not easily deformed during welding. The structural component 1 can also serve as an intermediate product, which is in a state between the raw material and the standard product (the weld quality can be identified after welding). Further adjustment and processing of the structural component 1 in this intermediate state is required to obtain the standard product.

[0175] Refer to FIG. 13 , which is a flow chart of a method for preparing a structural member 1 according to yet other embodiments of the present application.

[0176] In some embodiments, the method for preparing the through-hole welded structural member 1 further comprises the following steps: Through the following steps, the intermediate product can be prepared into a standard product.

[0177] S300: Structural component 1 and target component 2 are welded using a first welding energy value, forming a first weld mark 111a on first portion 111. The penetration of first weld mark 111a is greater than the thickness of first portion 111. The first welding energy value enables first portion 111 to be fully penetrated and connected to target component 2, thereby connecting structural component 1 and target component 2 together.

[0178] S400: Gradually reduce the welding energy until the penetration of the first weld mark 111a equals the thickness of the first portion 111. When the penetration of the first weld mark 111a equals the thickness of the first portion 111, the welding energy value is set to a second welding energy value. The penetration of the first weld mark 111a equal to the thickness of the first portion 111 is not strictly equal; a certain degree of error is permitted. The second welding energy value can just penetrate the first portion 111.

[0179] Continue to perform the following judgment steps.

[0180] S501: If the second welding energy value is used to weld the second portion 112 to form a second weld mark 112a, and the color of the second weld mark 112a just reaches the predetermined color, the structural component 1 is completed, and the obtained standard product can be used to identify the welding quality by appearance after being welded with other components.

[0181] S502: If the color of the second weld mark 112a does not reach the predetermined color when the second welding energy value is used to weld the second portion 112 to form the second weld mark 112a, the ability of the second portion 112 to receive welding energy is adjusted until the color of the second weld mark 112a just reaches the predetermined color when the second welding energy value is used to weld the second portion 112. The preparation of the structural component 1 is completed, and the obtained standard product can be used to identify the welding quality by appearance after being welded with other components.

[0182] There is no order for steps S501 and S502.

[0183] The predetermined color is pre-set based on the material properties of the second portion 112 and can be used to identify a cold weld and determine welding quality. For example, when the second weld mark 112a has a high penetration depth, the copper appears bright white. When the second weld mark 112a has a shallow penetration depth, the second weld mark 112a appears dark purple, which can be used as the predetermined color. The color of the second weld mark 112a reaching the predetermined color means that the penetration depth of the second weld mark 112a is at the critical point where the weld mark changes color from bright white to dark purple.

[0184] The essence of steps S501 and S502 is to determine whether the penetration depth of the second weld mark 112a formed using the second energy value is just at the critical point where the weld mark changes color from bright white to dark purple. If so, a standard product is obtained. If not, the energy required to receive welding power from the second portion 112 needs to be adjusted.

[0185] It should be understood that for standard products, when welding on the second portion 112 using the second welding energy value, the penetration depth of the second weld mark 112a formed needs to be at the critical point of staged color change. Thus, if external conditions cause the welding energy value to decrease, the second weld mark 112a will exceed the critical point and assume the predetermined color, thereby visually identifying the weld quality through the predetermined color.

[0186] When the structural component 1 in the standard product state is connected and assembled with the target component 2 by penetration welding during the assembly process, if the second portion 112 reaches a predetermined color, it means that the product has a cold weld or the welding quality is insufficient.

[0187] Just reaching the predetermined color means that the predetermined color just appears. That is, as long as a welding energy value greater than the second welding energy value is used, the second weld mark 112a will not show the predetermined color.

[0188] There are two situations in which the color of the second weld mark 112a does not exactly reach the predetermined color. The first situation is that when welding at the second portion 112 using the second welding energy value, the second weld mark 112a does not exhibit the predetermined color. This is because the second portion 112 has a strong ability to absorb welding energy. Therefore, it is necessary to further weaken the ability of the second portion to absorb welding energy in order to reduce the penetration depth of the formed second weld mark 112a, bringing it closer to the critical point of staged color change, until the penetration depth of the formed second weld mark 112a reaches the critical point of staged color change. The second situation is that when welding at the second portion 112 using the second welding energy value, the second weld mark 112a has already exhibited the predetermined color. This is because the second portion 112 has a weak ability to absorb welding energy, resulting in the penetration depth of the second weld mark 112a being lower than the critical point of staged color change. It is necessary to strengthen the ability of the second part 112 to receive welding energy so that the penetration of the formed second weld mark 112a increases and approaches the penetration depth of the critical point where the weld mark shows stage color change, until the penetration depth of the formed second weld mark 112a is at the critical point of stage color change.

[0189] It should be noted that each weld is completed, and the color of second weld mark 112a refers to the color of second weld mark 112a after a single weld. After adjusting the weld capacity of second portion 112, the welding operation is repeated to form second weld mark 112a on second portion 112, and then verify whether second weld mark 112a has reached the desired color. The entire process is a repetitive and continuous verification process.

[0190] The steps provided in the above embodiment can produce a standard product. When the structural component 1 is put into use, welding the structural component 1 to the target component 2 using a welding energy greater than the second welding energy value theoretically results in good weld quality. If external interference causes the actual welding energy to fall below the second welding energy value, the second weld mark 112a of the second portion 112 will assume a predetermined color, which can be used to identify weld quality. The first portion 111 provides effective welding, i.e., the first portion 111 is the effective welding zone; and the second portion 112 is used to identify weld quality after welding, i.e., the second portion 112 is the weld quality identification zone.

[0191] In some embodiments, the method of adjusting the ability of the second portion 112 to receive welding energy includes at least one of changing the thickness of the second portion 112 , changing the laser absorptivity of the second portion 112 , and changing the roughness of the second portion 112 .

[0192] It is understood that the ability of the second portion 112 to receive welding energy can be enhanced or weakened by changing the thickness of the second portion 112, changing the laser absorptivity of the second portion 112, or changing the roughness of the second portion 112. Alternatively, two or all three of these methods may be used.

[0193] The present application also provides a structural component 1 for penetration welding. The structural component 1 has a welding region 11 for welding to a target component 2. The welding region 11 includes a first portion 111 and a second portion 112. The second portion 112 has a weaker ability to receive welding energy than the first portion 111. The ability to receive welding energy refers to the depth of penetration formed at the weld. The first portion 111 is disposed around the outer periphery of the second portion 112. The first portion 111 has a first surface 1111 for receiving welding energy, and the second portion 112 protrudes from the first surface 1111.

[0194] The present application also provides a structural component 1 for penetration welding. The structural component 1 has a welding region 11 for welding to a target component 2. The welding region 11 includes a first portion 111 and a second portion 112. The second portion 112 has a weaker ability to receive welding energy than the first portion 111. The ability to receive welding energy refers to the depth of penetration formed at the weld. The first portion 111 is disposed around the periphery of the second portion 112. The first portion 111 has a first surface 1111 for receiving welding energy. The second portion 112 includes a second surface 1121 for receiving welding energy. The roughness of the first surface 1111 is greater than the roughness of the second surface 1121.

[0195] The present application also provides a structural component 1 for penetration welding. The structural component 1 has a welding region 11 for welding to a target component 2. The welding region 11 includes a first portion 111 and a second portion 112. The second portion 112 has a weaker ability to receive welding energy than the first portion 111. The ability to receive welding energy refers to the depth of penetration formed at the weld. The first portion 111 is disposed around the outer periphery of the second portion 112. The first portion 111 has a greater absorption rate of welding energy than the second portion 112.

[0196] It should be noted that the method for adjusting the ability of the second portion 112 to receive welding energy provided in this embodiment is to make adjustments based on the intermediate product so as to prepare the intermediate product into a standard product.

[0197] 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.

[0198] The above embodiments are intended only to illustrate the technical solutions of this application and are not intended to limit this application. Those skilled in the art will appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this application are intended to be within the scope of protection of this application.

Claims

1. A structural member for penetration welding, having a welding area for welding with a target member, the welding area comprising a first portion and a second portion, wherein: The ability of the second part to receive welding energy is weaker than that of the first part, wherein the ability to receive welding energy refers to the depth of penetration formed at the weld.

2. The penetration welded structural member according to claim 1, wherein: The first portion has a first surface for receiving welding energy, and the second portion protrudes from the first surface.

3. The penetration welded structural member according to claim 1 or 2, wherein: The first portion has a first surface for receiving welding energy, the second portion includes a second surface for receiving welding energy, and the roughness of the first surface is greater than the roughness of the second surface.

4. The structural member for penetration welding according to claim 3, wherein: The second portion protrudes from the first surface.

5. The penetration welded structural member according to any one of claims 1 to 4, wherein: The first part has a first surface for receiving welding energy, the second part has a second surface for receiving welding energy, the area of ​​the first surface is S1, the area of ​​the second surface is S2, and 0.1≤S2 / S1≤0.

4.

6. The penetration welded structural member according to any one of claims 1 to 4, wherein: The absorption rate of the first portion to the welding energy is greater than the absorption rate of the second portion to the welding energy.

7. The penetration welded structural member according to claim 6, wherein: The material of the first portion includes at least one of steel, aluminum, nickel, and copper.

8. The penetration welded structural member according to claim 6, wherein: The material of the second portion includes one of copper and aluminum.

9. The penetration welded structural member according to any one of claims 1 to 8, wherein: The first part is arranged around the outer periphery of the second part.

10. A battery cell, characterized in that: include: The structural member according to any one of claims 1 to 9; A target part is welded to the structural part.

11. The battery cell according to claim 10, wherein: The battery cell comprises: Electrode terminal; Extreme ears; A current collecting member, used to connect the electrode terminal to the electrode tab; Any two of the electrode terminal, the current collecting member, and the electrode tab are respectively the target component and the structural component.

12. A battery comprising the battery cell according to claim 10 or 11.

13. A battery comprising: A plurality of battery cells, each having an electrode terminal; The structural member according to any one of claims 1 to 9 is welded to the electrode terminal to achieve electrical connection of the plurality of battery cells.

14. An electrical device, comprising the battery cell according to claim 10 or 11, and / or comprising the battery according to claim 12 or 13, wherein the battery cell or the battery is used to provide electrical energy.

15. A method for judging the welding quality of a structural part and a target part, wherein the structural part has a welding area for welding with the target part, the welding area includes a first part and a second part, wherein: The ability of the second part to receive welding energy is weaker than that of the first part, wherein the ability to receive welding energy refers to the depth of penetration formed at the weld, and the structural part and the target part are welded at the first part and the second part by a first welding energy value to form a first weld mark in the first part and a second weld mark in the second part. If the color of the second weld mark is a predetermined color, the penetration of the first weld mark is less than or equal to the thickness of the first part.

16. A method for preparing a structural part for penetration welding, comprising: Providing a structural member having a welding region for welding to a target member; A first portion and a second portion are formed in the welding region, and the ability of the second portion to receive welding energy is weaker than that of the first portion.

17. The method for preparing a structural member for penetration welding according to claim 16, wherein: The preparation method further comprises: The structural component and the target component are welded by using a first welding energy value, and a first weld mark is formed by welding at the first portion, wherein the penetration of the first weld mark is greater than the thickness of the first portion; gradually reducing the welding energy value until the penetration of the first weld mark is equal to the thickness of the first portion; When the penetration of the first weld mark is equal to the thickness of the first portion, the welding energy value is the second welding energy value: If the second welding energy value is used to weld the second portion to form a second weld mark, the color of the second weld mark just reaches a predetermined color, and the preparation of the structural component is completed; If the color of the second weld mark does not reach the predetermined color when the second welding energy value is used to weld the second part to form a second weld mark, the ability of the second part to receive welding energy is adjusted until the color of the second weld mark just reaches the predetermined color when the second part is welded using the second welding energy value, and the preparation of the structural part is completed.

18. The method for preparing a structural member for penetration welding according to claim 17, wherein: The method for adjusting the ability of the second portion to receive welding energy comprises: at least one of changing the thickness of the second portion, changing the laser absorption rate of the second portion, and changing the roughness of the second portion.

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