Welding method and welding tool for single battery

Abstract

The invention discloses a welding method and a welding tool for a single battery. The welding method of the single battery comprises the steps that a positioning device is provided, the positioning device is provided with an adapter piece installation position and an electrode assembly installation position, the electrode assembly installation position is arranged on at least one side of the adapter piece installation position in the first direction, the electrode assembly installation position is provided with a supporting face used for supporting an electrode assembly, and the supporting face is configured to be arranged to form an obtuse angle with an adapter piece; the first direction intersects with the height direction of the positioning device, placing the switching piece of the single electrode at the switching piece mounting position, and placing the electrode assembly of the single battery at the electrode assembly mounting position. Providing a pressing piece, and pressing the pressing piece on the pre-pressing area of the tab of the electrode assembly, so that the tab of the electrode assembly is pressed on the adapter plate; and welding the tab and the adapter plate. The supporting surface and the switching piece are arranged at the obtuse angle, so that the first end of the battery monomer is higher than the second end, and the pressing amount of the upper surface of the tab is reduced, so that the redundancy of the tab is reduced.

Description

Technical Field

[0001] The present application relates to the field of battery manufacturing technology, and in particular to a welding method and welding tooling for a battery cell. Background Art

[0002] During battery production, the tabs of battery cells are welded to the adapter to ensure smooth flow of current from the battery cells to the external circuit. Imprecise tab length, shape, or position during welding can lead to excessive tabs during cell assembly, a phenomenon known as "tab redundancy." This can lead to underutilized battery space or prevent complete compaction during cell assembly, impacting battery performance and lifespan. Summary of the Invention

[0003] In view of the above problems, the present application provides a welding method and welding tool for a battery cell. Before welding the tab and the adapter, the first end of the battery cell is raised above the second end so that the battery cell can be tilted at a certain angle relative to the adapter, thereby reducing the redundancy on the inner side of the bent tab.

[0004] In a first aspect, the present application provides a method for welding a battery cell, comprising: A positioning device is provided, the positioning device having an adapter plate mounting position and an electrode assembly mounting position, the adapter plate mounting position being provided with an electrode assembly mounting position on at least one side thereof along a first direction, the electrode assembly mounting position having a support surface for supporting the electrode assembly, the support surface being configured to form an obtuse angle with the adapter plate, and the first direction intersecting with a height direction of the positioning device; Place the adapter plate of the electrode unit in the adapter plate installation position, and place the electrode assembly of the battery unit in the electrode assembly installation position. Provide a clamping piece; Pressing the pressing member on the pre-pressing area of the electrode tab of the electrode assembly so that the electrode tab of the electrode assembly is pressed against the adapter; Solder the tabs and adapters. Before the tab is welded to the adapter, the support surface and the adapter are set at an obtuse angle, so that the first end of the battery cell can be higher than the second end, reducing the downward pressure on the upper surface of the tab to reduce the redundancy of the tab. At the same time, the gap between the tab and the adapter is reduced, improving the welding effect and ensuring a more stable and reliable connection. In addition, the support surface and the adapter are set at an obtuse angle, which can also improve the heat distribution during the welding process. The traditional horizontal placement of battery cells may cause heat to concentrate around the welding point, which can easily cause uneven thermal stress and affect the welding quality. Adjusting the tilt angle helps to distribute heat more evenly, thereby reducing the possibility of local overtemperature, reducing the concentration of thermal stress, and improving welding stability and consistency.

[0005] In some embodiments, pressing the pressing member against the pre-pressing area of the electrode tab of the electrode assembly includes: The surface of the pressing piece facing the electrode ear is set as an outwardly convex arc surface and a flat surface, the arc surface and the flat surface are connected, and the pressing piece is set in the pre-pressing area so that the arc surface is set between the main body and the flat surface of the electrode assembly, and pressure is applied to the pressing piece so that at least part of the arc surface and at least part of the flat surface are respectively pressed on the pre-pressing area.

[0006] The use of an outwardly convex arc surface to press the tab can better adapt to the curved structure of the tab (the area near the root of the tab), so that the clamping piece can better fit the surface of the tab. When the clamping piece applies pressure to the tab, the force exerted by the clamping piece on the surface of the tab is more uniform, reducing local excessive compression or stretching of the tab, thereby reducing the generation of tab redundancy and helping to improve welding stability and consistency.

[0007] In some embodiments, there are two electrode assemblies, which are respectively arranged on both sides of the adapter along the first direction, and the pressing member is simultaneously pressed on the pre-pressing areas of the two electrode assemblies so that the tabs of the two electrode assemblies respectively abut against the adapter. In this way, the electrode tabs and the adapter sheets of the two electrode assemblies can be welded, and the redundancy of the electrode tabs of the two electrode assemblies can be reduced by arranging the two electrode assemblies at an angle.

[0008] In some embodiments, pressing the pressing member simultaneously on the pre-pressing areas of the two electrode assemblies includes: Arc surfaces are respectively provided at both ends of the plane of the pressing member along the first direction, and pressure is applied to the pressing member so that at least part of the plane is pressed against the pre-pressing areas of the two electrode assemblies at the same time, and at least part of the arc surfaces at different positions are pressed against the pre-pressing areas of different electrode assemblies.

[0009] As a result, the different curved surfaces of the compression member can better adapt to the curved structures of the tabs of different electrode assemblies, allowing them to better fit the surface of the tab. When the compression member applies pressure to the tab, the force acting on the tab surface is more uniform, reducing localized excessive compression or stretching of the tab, thereby reducing the occurrence of tab redundancy and helping to improve welding stability and consistency.

[0010] In some embodiments, the clamping member includes a first plate body, a second plate body and a bending portion, the first plate body is respectively connected to the bending portion at both ends along the first direction, the bending portion is connected to the second plate body, the first plate body and the second plate body are arranged at an angle, and the surface of the bending portion facing the pole ear has an arc surface.

[0011] The curved surface design of the compression element's bent portion adapts to the curvature of the area near the base of the tab. This geometric adaptability ensures more uniform pressure distribution, effectively reducing the localized stress concentration caused by traditional flat pressure application, minimizing excessive compression or stretching of the tab, and thus reducing tab redundancy.

[0012] In some embodiments, the radius of the arc surface is r, and the value range of r is set to 0.2 mm-0.5 mm.

[0013] Setting r within the above range can prevent the pressing member from over-pressing or under-pressing the tab. Over-pressing will cause the arc surface to press on the root of the tab, resulting in loose crimping of the area pressed by the plane, affecting the welding quality. Under-pressing will make the crimping area too small, which may easily lead to excessive redundancy of the tab. This will make the force exerted by the pressing member on the tab more uniform and reduce the redundancy of the tab. On the other hand, it can give the tab a certain crimping area and make the welding area of the tab smoother, so as to reduce the possibility of loose welding in the welding area during welding, thereby improving the welding quality.

[0014] In some embodiments, the distance between the side of the main body facing away from the positioning device and the support surface is h, the angle between the support surface and the adapter surface is B, the radius of the arc surface is r, the main body has a first end facing away from the adapter sheet and a second end facing the adapter sheet, and along the direction from the first end to the second end, the minimum distance from the weld mark on the surface of the tab to the main body is W, the size of the tab is L, and the value of r is LWh*cos(B-90°).

[0015] Associating r with B, when B changes, the size of r can be adjusted according to the above formula so that the arc surface is pressed on the tab at the appropriate position to prevent the clamping member from over-pressing or under-pressing the tab, thereby better controlling the redundancy of the tab and the welding quality of the tab.

[0016] In some embodiments, an obtuse angle between the supporting surface and the transition surface is B, and the value range of B is set to 165°-175°.

[0017] Setting B within the above range can match B with r, which can reduce the misalignment of the multi-layer tabs and the redundancy of the tabs on the one hand, and prevent the arc surface from being over-pressurized or under-pressurized on the other hand.

[0018] In some embodiments, the tab has an insulating layer region and a non-insulating layer region, the insulating layer region is located between the non-insulating layer region and the main body of the electrode assembly, the insulating layer region has an insulating layer, and the pressing member is pressed against the non-insulating layer region.

[0019] Since the insulating layer in the insulating layer area has a certain thickness, the thickness of the tab in the insulating layer area is greater than that of the non-insulating layer area. Pressing the pressing piece on the non-insulating layer area can make the multi-layer tabs in the non-insulating layer area flat and tightly fit together, so as to reduce the possibility of cold welding during the welding process and improve the welding quality; at the same time, it can also reduce the redundancy of the tab.

[0020] In some embodiments, along the first direction, the size of the pre-pressing area is ΔL, the size of the adapter along the first direction is L1, ΔL is set to be greater than or equal to 5 mm and set to be less than L1, and the first direction is parallel to the adapter.

[0021] In this way, the tab can have a certain welding area to ensure the firmness and stability of the welding.

[0022] In some embodiments, the main body has a first end facing away from the adapter plate and a second end facing the adapter plate. Along the direction from the first end to the second end, the minimum dimension from the pre-pressing area to the first end is L2, and the value range of L2 is set to 8mm-11mm.

[0023] Setting L2 within the above range can prevent the pressing part from pressing on the insulating layer area, thereby preventing the multi-layer tabs in the non-insulating layer area from being loosely pressed, thereby reducing the redundancy of the tabs, and allowing the pre-pressing area to have a certain pressing area, so that the tabs and the adapter can be welded within the pressing area to ensure the firmness and stability of the welding.

[0024] In a second aspect, the present application provides a welding tool, which is used in a method for welding a battery cell. The welding tool includes: A positioning device, the positioning device having an adapter plate mounting position and an electrode assembly mounting position, the electrode assembly mounting position being provided on at least one side of the adapter plate mounting position along a first direction, the adapter plate mounting position being used to place the adapter plate, the electrode assembly mounting position being used to place the electrode assembly, the electrode assembly mounting position having a support surface for supporting the electrode assembly, the support surface being configured to form an obtuse angle with the adapter plate, the positioning device being used to position the electrode assembly and the adapter plate respectively along a first direction and a second direction, the first direction and the second direction being perpendicular, and a common plane of the first direction and the second direction intersecting with a height direction of the positioning device; The pressing member is located above the positioning device and is configured to move along the height direction of the positioning device to press the tab onto the adapter.

[0025] The clamping element allows the tab to fit more evenly against the adapter, reducing tab redundancy during welding. The positioning device ensures the accuracy of the relative position between the electrode assembly and the adapter, ensuring a good welding effect.

[0026] In some embodiments, the clamping member includes a first plate body, a second plate body and a bending portion, the first plate body is connected to the bending portion at both ends along the first direction, the first direction is parallel to the first plate body, the bending portion is connected to the second plate body, the first plate body and the second plate body are arranged at an angle, and the surface of the bending portion facing the pole ear has an outwardly convex arc surface. The convex arc surface can match the shape of the area near the root of the tab, reducing the stress concentration on the tab during the crimping process of the clamping piece, making the force exerted by the clamping piece on the surface of the tab more uniform, so as to reduce the local excessive compression or stretching of the tab, thereby reducing the redundancy of the tab.

[0027] In some embodiments, the radius of the arc surface is r, and the value range of r is 0.2 mm-0.5 mm.

[0028] Setting r within the above range can prevent the pressing member from over-pressing or under-pressing the tab. Over-pressing will cause the arc surface to press on the root of the tab, resulting in loose crimping of the area pressed by the plane, affecting the welding quality. Under-pressing will make the crimping area too small, which may easily lead to excessive redundancy of the tab. This will make the force exerted by the pressing member on the tab more uniform and reduce the redundancy of the tab. On the other hand, it can give the tab a certain crimping area and make the welding area of the tab smoother, so as to reduce the possibility of loose welding in the welding area during welding, thereby improving the welding quality.

[0029] In some embodiments, the positioning device comprises: The support assembly includes a support member, a first positioning member and a second positioning member. The support assembly has an electrode assembly mounting position, and the upper surface of the support assembly has a supporting surface. The first positioning member and the second positioning member are respectively arranged on the support member. The first positioning member is used to position the electrode assembly along a first direction, and the second positioning member is used to position the electrode assembly along a second direction. The second direction is perpendicular to the first direction, and the plane where the second direction and the first direction are located is the same as the height direction of the positioning device.

[0030] Therefore, the first positioning member and the second positioning member respectively position the electrode assembly, thereby ensuring the accuracy of the relative position between the electrode assembly and the adapter.

[0031] In some embodiments, there are two second positioning members, the two second positioning members are spaced apart along the second direction, and at least one of the two second positioning members is adjustably connected to the supporting member along the second direction.

[0032] Thus, electrode assemblies of different sizes along the second direction can be positioned, thereby increasing the applicable range of the positioning device.

[0033] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference numerals are used throughout the drawings to represent the same components. In the drawings: Figure 1 This is a structural diagram of an electrode assembly in some embodiments of the present application being pressed against a transfer sheet by a pressing member; Figure 2 This is a structural diagram of a welding tool according to some embodiments of the present application; Figure 3 This is an axonometric view of a clamping member in a welding tool according to some embodiments of the present application.

[0035] The accompanying drawings in the specific implementation manner are as follows: 10. Electrode assembly; 11. Main body; 111. First end; 112. Second end; 12. Tab; 121. Insulating layer region; 122. Non-insulating layer region; 20. Adapter; 300. Welding tooling; 310, positioning device; 311, support assembly; 3111, support member; 31111, support surface; 3112, first positioning member; 3113, second positioning member; 320, pressing member; 321, first plate; 3211, plane; 322, second plate; 323, bending portion; 3231, arc surface; X, first direction; Y, second direction; Z, height direction. DETAILED DESCRIPTION

[0036] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments 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 figure descriptions are intended to cover non-exclusive inclusions.

[0038] In the description of the embodiments of this application, the technical terms "first," "second," etc. are used only to distinguish different objects and should not be understood to indicate or imply relative importance or to implicitly indicate the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise specifically defined.

[0039] References to "embodiments" herein mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present 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. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0040] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0041] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0042] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limiting the embodiments of the present application.

[0043] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0044] During the battery production process, the tabs of the battery cells are welded to the adapter sheets to ensure that the current of the battery cells can flow smoothly to the external circuit. When the length, shape or position of the tabs are not designed accurately during the welding process, excessive tab parts may be formed during the core assembly process, which is the so-called "tab redundancy". Tab redundancy may lead to insufficient utilization of the battery space, or failure to fully compact the core during assembly, thereby affecting the performance and life of the battery. Specifically, when there is redundancy in the welded tabs, the electrode assembly of the battery cell needs to be folded so that the tabs are bent at a certain angle before the electrode assembly is placed into the shell. When folding, excess parts will be generated on the inner side of the bent position of the tabs. When the battery is working, especially in situations with vibration, the excess parts will be subjected to reciprocating bending stress, causing the redundant parts to break. On the one hand, this affects the flow area of the tabs, and on the other hand, the tab breakage may cause the risk of short circuit.

[0045] In view of this, the present application provides a method for welding a battery cell. Before the tab is welded to the adapter, the first end of the battery cell is raised above the second end so that the battery cell can be tilted at a certain angle relative to the adapter, thereby reducing the downward pressure on the upper surface of the tab to reduce the redundancy of the tab. At the same time, the gap between the tab and the adapter is reduced, thereby improving the welding effect and ensuring a more stable and reliable connection. In addition, the tilt angle can also improve the heat distribution during welding. The horizontal placement of traditional battery cells may cause heat to concentrate around the welding point, which can easily cause uneven thermal stress and affect the welding quality. Adjusting the tilt angle helps to distribute the heat more evenly, thereby reducing the possibility of local excessive temperature, reducing the concentration of thermal stress, and improving welding stability and consistency.

[0046] The present application provides a battery cell welding method that can be used for, but is not limited to, the welding of lithium batteries. Specifically, it can be used for welding a single tab and an adapter, and can also be used for welding two tabs and the same adapter.

[0047] For the convenience of explanation, please refer to the following examples. Figure 1 , a welding method of a battery cell in some embodiments of the present application is used as an example for description.

[0048] The welding method of the battery cell includes: A positioning device 310 is provided. The positioning device 310 has an adapter plate mounting position and an electrode assembly mounting position. The electrode assembly mounting position is provided on at least one side of the adapter plate mounting position along a first direction X. The electrode assembly mounting position has a support surface 31111 for supporting the electrode assembly 10. The support surface 31111 is configured to form an obtuse angle with the adapter plate 20. The first direction X intersects the height direction Z of the positioning device 310. The adapter plate 20 of the electrode cell is placed in the adapter plate mounting position, and the electrode assembly 10 of the battery cell is placed in the electrode assembly mounting position.

[0049] The supporting surface 31111 can make the electrode assembly 10 tilt at a certain angle relative to the adapter sheet 20, that is, the first end 111 of the main body 11 of the electrode assembly 10 facing away from the adapter sheet 20 is higher than the second end 112 of the main body 11 facing the adapter sheet 20. The main body 11 of the electrode assembly 10 refers to the part connected to the tab 12. The first end 111 is higher than the second end 112 means that: along the height direction Z of the positioning device 310, the minimum dimension from the first end 111 to the adapter sheet 20 is greater than the minimum dimension from the second end 112 to the adapter sheet 20, or the maximum dimension from the first end 111 to the adapter sheet 20 is greater than the maximum dimension from the second end 112 to the adapter sheet 20. For example, Figure 1 For example, along the height direction Z of the positioning device 310 , the maximum dimension from the first end 111 to the adapter plate 20 is Hmax1 , and the maximum dimension from the second end 112 to the adapter plate 20 is Hmax2 , where Hmax1 is greater than Hmax2 .

[0050] A pressing member 320 is provided and pressed against the pre-pressing area of the electrode tab 12 of the electrode assembly 10 so that the electrode tab 12 of the electrode assembly 10 is pressed against the adapter 20 .

[0051] In one example, a positioning component can be provided at the bottom of the adapter plate 20 to position the adapter plate 20. The clamping member 320 can also be connected to the positioning component via a fastener, and the pre-tightening force of the fastener is used to clamp the adapter plate 20 and the tab 12. The fasteners include but are not limited to a combination of bolts or screws and nuts. In other examples, the clamping member 320 can be driven by a driving member, which provides downward pressure to the clamping member 320 to achieve clamping and positioning of the tab 12 and the adapter plate 20. The driving member can be, but is not limited to, a linear driving member such as a cylinder or an electric push rod.

[0052] Optionally, the pressing member 320 may be, but is not limited to, a U-shaped pressing plate or a pressing block.

[0053] The tab 12 and the adapter 20 are welded.

[0054] Optionally, the tab 12 and the adapter plate 20 may be welded by ultrasonic welding.

[0055] Before welding the tab 12 to the adapter 20, the first end 111 of the battery cell is raised above the second end 112 so that the battery cell can be tilted at a certain angle relative to the adapter 20, thereby reducing the downward pressure on the upper surface of the tab 12 and reducing the redundancy of the tab 12. At the same time, the gap between the tab 12 and the adapter 20 is reduced, thereby improving the welding effect and ensuring a more stable and reliable connection. In addition, the tilt angle can also improve the heat distribution during welding. The horizontal placement of traditional battery cells may cause heat to concentrate around the welding point, which can easily cause uneven thermal stress and affect the welding quality. Adjusting the tilt angle helps to distribute heat more evenly, thereby reducing the possibility of local overtemperature, reducing the concentration of thermal stress, and improving welding stability and consistency.

[0056] The electrode assembly 10 includes a positive electrode, a negative electrode, and a separator, which is positioned between the positive and negative electrodes. 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, positioned between the positive and negative electrodes, prevents short circuits while allowing the active ions to pass through.

[0057] The electrode assembly 10 may be a wound structure, a laminated structure, or a mixed structure of wound and laminated structures.

[0058] In some embodiments, the electrode assembly 10 is a wound structure in which the positive electrode sheet and the negative electrode sheet are wound into a wound structure.

[0059] In some embodiments, the electrode assembly 10 is a laminated structure.

[0060] As an example, multiple positive electrode sheets and multiple negative electrode sheets can be provided respectively, and the multiple positive electrode sheets and the multiple negative electrode sheets can be alternately stacked.

[0061] As an example, a plurality of positive electrode sheets may be provided, and the negative electrode sheet may be folded to form a plurality of stacked folded segments, with a positive electrode sheet being sandwiched between adjacent folded segments.

[0062] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of stacked folded segments.

[0063] As an example, a plurality of separators may be provided, each of which is disposed between any adjacent positive electrode sheets or negative electrode sheets.

[0064] As an example, the separator may be provided continuously, and may be provided between any adjacent positive electrode sheets or negative electrode sheets by folding or winding.

[0065] In some embodiments, a tab 12 is provided at one end of the main body 11 of the electrode assembly 10, and the tab 12 can conduct current from the electrode assembly 10. The tab 12 includes a positive tab and a negative tab.

[0066] In some embodiments, pressing the pressing member 320 against the pre-pressing area of the tab 12 of the electrode assembly 10 includes: The surface of the clamping member 320 facing the tab 12 is set as an outwardly convex arc surface 3231 and a flat surface 3211, and the arc surface 3231 and the flat surface 3211 are connected. The clamping member 320 is set in the pre-pressing area so that the arc surface 3231 is set between the main body 11 and the flat surface 3211, and pressure is applied to the clamping member 320 so that at least part of the arc surface 3231 and at least part of the flat surface 3211 are respectively pressed in the pre-pressing area.

[0067] In one example, the pressing member 320 includes a first plate 321, a second plate 322, and an arc plate. The first plate 321 is perpendicular to the second plate 322, and the first plate 321 and the second plate 322 are connected by the arc plate. Specifically, the pressing member 320 can be formed by stamping so that the first plate 321 and the second plate 322 are generally L-shaped. The outer surface of the arc plate can be used as an arc surface 3231, and the plane 3211 tangent to the arc surface 3231 can be located on the first plate 321 or on the second plate 322. The angle between the first plate 321 and the second plate 322 can also be less than or greater than 90°.

[0068] The use of the convex curved surface 3231 to press against the tab 12 can better adapt to the curved structure of the tab 12 (the area near the base of the tab), allowing the pressing member 320 to better fit the surface of the tab 12. When the pressing member 320 applies pressure to the tab 12, the force exerted by the pressing member 320 on the surface of the tab 12 is more uniform, reducing excessive compression or stretching of the tab 12 in some areas, thereby reducing the redundancy of the tab 12 and helping to improve welding stability and consistency.

[0069] In some embodiments, the number of electrode assemblies 10 is two, and the two electrode assemblies 10 are respectively arranged on both sides of the adapter 20 along the first direction X, and the first direction X is parallel to the adapter 20. The clamping member 320 is pressed on the pre-pressing area of the two electrode assemblies 10 at the same time so that the tabs 12 of the two electrode assemblies 10 are respectively in contact with the adapter 20.

[0070] When there are two electrode assemblies 10, the two electrode assemblies 10 need to have the same tabs 12 of polarity welded to the same adapter 20. After welding the adapter 20 to the end cap of the battery cell, the two electrode assemblies 10 are finally flipped at a preset angle and installed in the outer shell of the battery cell. When the two tabs 12 of different polarities of the electrode assembly 10 are welded to the adapter 20, the material of the adapter 20 can be the same as that of the tabs 12. For example, the first tab of the electrode assembly 10 is made of aluminum, and the second tab is made of copper. During welding, the adapter 20 welded to the first tab can be made of aluminum, and the adapter 20 welded to the second tab can be made of copper.

[0071] Thus, the electrode tabs 12 and the adapter sheets 20 of the two electrode assemblies 10 can be welded. The two electrode assemblies 10 are arranged at an angle, which can reduce the redundancy of the electrode tabs 12 of the two electrode assemblies 10.

[0072] In some embodiments, pressing the pressing member 320 simultaneously on the pre-pressing areas of the two electrode assemblies 10 includes: Arc surfaces 3231 are respectively provided at both ends of the plane 3211 of the pressing member 320 along the first direction X, and pressure is applied to the pressing member 320 so that at least part of the plane 3211 is pressed against the pre-pressing areas of the two electrode assemblies 10 at the same time, and at least part of the arc surfaces 3231 at different positions are pressed against the pre-pressing areas of different electrode assemblies 10.

[0073] As a result, the different curved surfaces 3231 of the pressing member 320 can better adapt to the curved structures of the tabs 12 of different electrode assemblies 10, so as to better fit the surface of the tabs 12. When the pressing member 320 applies pressure to the tabs 12, the force exerted by the pressing member 320 on the surface of the tabs 12 is made more uniform, reducing local excessive compression or stretching of the tabs 12, thereby reducing the redundancy of the tabs 12 and helping to improve welding stability and consistency.

[0074] In some embodiments, the clamping member 320 includes a first plate body 321, a second plate body 322 and a bending portion 323. The first plate body 321 is connected to the bending portion 323 at both ends along the first direction X, and the bending portion 323 is connected to the second plate body 322. The first plate body 321 and the second plate body 322 are arranged at an angle, and the bending portion 323 has an arc surface 3231 on the side surface facing the tab 12.

[0075] Optionally, the second plates 322 at both ends of the first plate 321 along the first direction X are parallel to each other. The pressing member 320 can be stamped to form an integral structure with the first plate 321, the second plate 322, and the bent portion 323. The bent portion 323 can be a stamped portion. The bent portion 323 is a circular arc plate. In other examples, the first plate 321, the bent portion 323, and the second plate 322 can be welded to form an integral structure.

[0076] The curved surface 3231 design of the bending portion 323 of the clamping member 320 can adapt to the curved shape of the area near the root of the tab 12 to make the pressure distribution more uniform, effectively reducing the local stress concentration caused by traditional plane pressure application, and reducing the local excessive compression or stretching of the tab 12, thereby reducing the redundancy of the tab 12.

[0077] In some embodiments, the radius of the arc surface 3231 is r, and the value range of r is set to 0.2 mm-0.5 mm.

[0078] Setting r within the above range prevents the pressing member 320 from over- or under-pressing the tab 12. Over-pressing the tab 12 can cause the arc surface 3231 to press against the base of the tab 12, resulting in a loose connection in the area pressed by the flat surface 3211 and affecting welding quality. Under-pressing the connection area can reduce the area of the connection, making the tab 12 prone to excessive excess. This ensures a more uniform force applied by the pressing member 320 to the tab 12, reducing excess. Furthermore, the tab 12 can have a defined contact area, making the welding area of the tab 12 smoother, reducing the likelihood of a loose connection during welding and improving welding quality.

[0079] In some embodiments, the distance between the side of the main body 11 facing away from the positioning device 310 and the support surface 31111 is h, the angle between the support surface 31111 and the adapter surface is B, the radius of the arc surface 3231 is r, the main body 11 has a first end 111 facing away from the adapter plate 20 and a second end 112 facing the adapter plate 20, and along the direction from the first end 111 to the second end 112, the minimum distance from the weld mark on the surface of the tab 12 to the main body 11 is W, the size of the tab 12 is L, and the value of r is LWh*cos(B-90°).

[0080] Associating r with B, when B changes, the size of r can be adjusted according to the above formula so that the arc surface 3231 is pressed on the tab 12 at a suitable position to prevent the clamping member 320 from over-pressing or under-pressing the tab 12, thereby better controlling the redundancy of the tab 12 and the welding quality of the tab 12.

[0081] In some embodiments, the value range of B is set to 165°-175°.

[0082] Setting B within the above range can match B with r, which can reduce the misalignment of the multi-layer tabs 12 and the redundancy of the tabs 12 on the one hand; and prevent the arc surface 3231 from being over-pressurized or under-pressurized on the other hand.

[0083] In some embodiments, the tab 12 has an insulating layer region 121 and a non-insulating layer region 122 . The insulating layer region 121 is located between the non-insulating layer region 122 and the main body 11 of the electrode assembly 10 . The insulating layer region 121 has an insulating layer, and the pressing member 320 is pressed against the non-insulating layer region 122 .

[0084] Taking the material of the tab 12 as aluminum as an example, in order to reduce the possibility of short circuit, the area near the root of each layer of the tab 12 is wrapped with an insulating layer, which can be specifically aluminum oxide. Since aluminum oxide has a high hardness and a certain thickness, when the arc of the clamping member 320 is pressed on the non-insulating layer area 122, it is easy for the plane 3211 to press on the surface of the tab 12 with less force, and this area is the welding area. On the one hand, it makes the tab 12 prone to excessive stretching or shrinking, increasing the redundancy of the tab 12; on the other hand, it is easy to produce cold welding, affecting the welding quality. Therefore, pressing the clamping member 320 on the non-insulating layer area 122 can improve the above situation.

[0085] Since the insulating layer of the insulating layer region 121 has a certain thickness, the thickness of the tab 12 in the insulating layer region 121 is greater than the thickness of the non-insulating layer region 122. Pressing the pressing member 320 against the non-insulating layer region 122 can make the multiple tabs 12 in the non-insulating layer region 122 flat and tightly fit together, thereby reducing the possibility of cold welding during the welding process and improving the welding quality; at the same time, it can also reduce the redundancy of the tab 12.

[0086] In some embodiments, along the first direction X, the size of the pre-pressing area is ΔL, the size of the adapter plate 20 along the first direction X is L1, ΔL is set to be greater than or equal to 5 mm and set to be less than L1, and the first direction X is parallel to the adapter plate 20.

[0087] Thus, the tab 12 can have a certain welding area to ensure the firmness and stability of the welding.

[0088] In some embodiments, the main body 11 has a first end 111 facing away from the adapter plate 20 and a second end 112 facing the adapter plate 20. Along the direction from the first end 111 to the second end 112, the minimum dimension from the pre-pressing area to the first end 111 is L2, and the value range of L2 is set to 8mm-11mm.

[0089] By setting L2 within the above range, the pressing member 320 will not be pressed on the insulating layer area 121, thereby preventing the multi-layer tabs 12 in the non-insulating layer area 122 from being pressed loosely, thereby reducing the redundancy of the tabs 12. The pre-pressing area can have a certain pressing area so that the tabs 12 and the adapter 20 can be welded within the pressing area to ensure the firmness and stability of the welding.

[0090] For the convenience of explanation, please refer to the following examples. Figure 1-Figure 3 , a welding tool 300 according to some embodiments of the present application is used as an example for description.

[0091] The welding fixture 300 is used in a method for welding battery cells and includes a positioning device 310 and a pressing member 320. The positioning device 310 has an adapter plate mounting position and an electrode assembly mounting position. The adapter plate mounting position is provided with an electrode assembly mounting position on at least one side along a first direction X. The adapter plate mounting position is used to place the adapter plate 20, and the electrode assembly mounting position is used to place the electrode assembly 10. The electrode assembly mounting position has a support surface 31111 for supporting the electrode assembly 10. The support surface 31111 is configured to form an obtuse angle with the adapter plate 20. The first direction X intersects the height direction Z of the positioning device 310. The pressing member 320 is located above the positioning device 310 and is configured to move along the height direction Z of the positioning device 310 to press the electrode plate onto the adapter plate 20.

[0092] Optionally, a positioning groove may be provided on the support surface 31111, and the electrode assembly 10 may be embedded in the positioning groove to achieve positioning along the first direction X and the second direction Y. Alternatively, a plurality of positioning blocks or other components may be provided on the support surface 31111 to position the electrode assembly 10 at both ends along the first direction X and at both ends along the second direction Y, respectively.

[0093] The pressing member 320 may be, but is not limited to, a flat pressing plate, a U-shaped pressing plate, or a pressing block.

[0094] Optionally, an obtuse angle between the supporting surface 31111 and the adapter plate 20 is B, and the value range of B is 165°-175°.

[0095] The clamping member 320 can be provided to make the tab 12 fit more smoothly with the adapter 20, thereby reducing the redundancy of the tab 12 during welding. The positioning device 310 can ensure the accuracy of the relative position of the electrode assembly 10 and the adapter 20 to ensure the welding effect.

[0096] In some embodiments, please refer to Figure 1 and Figure 3 The pressing member 320 includes a first plate body 321, a second plate body 322 and a bending portion 323. The first plate body 321 is connected to the bending portion 323 at both ends along the first direction X. The first direction X is parallel to the first plate body 321. The bending portion 323 is connected to the second plate body 322. The first plate body 321 and the second plate body 322 are arranged at an angle, and the bending portion 323 has a convex arc surface 3231 on the side facing the tab 12.

[0097] The convex arc surface 3231 can match the shape of the area near the root of the pole tab 12, reducing the stress concentration on the pole tab 12 during the crimping process of the clamping piece 320, making the force exerted by the clamping piece 320 on the surface of the pole tab 12 more uniform, so as to reduce the local excessive compression or stretching of the pole tab 12, thereby reducing the redundancy of the pole tab 12.

[0098] In some embodiments, the welding tool 300 further includes a drive mechanism ( Figure 2 (not shown), the driving mechanism is connected to the pressing member 320, and the driving mechanism is used to drive the pressing member 320 to move along the height direction Z of the positioning device 310 so that the tab 12 is pressed against the adapter 20.

[0099] The driving mechanism may be, but is not limited to, a linear driving component such as a cylinder, an electric push rod or a hydraulic push rod.

[0100] In some embodiments, please refer to Figure 1 The radius of the arc surface 3231 is r, and the value range of r is 0.2mm-0.5mm.

[0101] Setting r within the above range can prevent the clamping member 320 from over-pressing or under-pressing the tab 12. Over-pressing will cause the arc surface 3231 to press on the root of the tab 12, resulting in loose crimping of the area pressed by the plane 3211, affecting the welding quality. Under-pressing will make the crimping area too small, which may easily lead to excessive redundancy of the tab 12. This will make the force exerted by the clamping member 320 on the tab 12 more uniform, reduce the redundancy of the tab 12, and on the other hand, make the tab 12 have a certain crimping area, make the welding area of the tab 12 smoother, and reduce the possibility of loose welding in the welding area during welding, thereby improving the welding quality.

[0102] In some embodiments, please refer to Figure 2 The positioning device 310 includes a support assembly 311, which includes a support member 3111, a first positioning member 3112 and a second positioning member 3113. The support assembly 311 has an electrode assembly mounting position, and the upper surface of the support assembly 311 has a supporting surface 31111. The first positioning member 3112 and the second positioning member 3113 are respectively arranged on the support member 3111. The first positioning member 3112 is used to position the electrode assembly 10 along the first direction X, and the second positioning member 3113 is used to position the electrode assembly 10 along the second direction Y. The second direction Y is perpendicular to the first direction X, and the plane where the second direction Y and the first direction X are located is the same as the height direction Z of the positioning device 310.

[0103] The supporting member 3111 may be a single piece, or may be an integrated structure formed by interconnecting multiple pieces, such as an integrated structure formed by connecting multiple plates by bolts or welding.

[0104] In one example, the first positioning member 3112 is a positioning bar, and the length direction of the positioning bar is the same as the second direction Y.

[0105] The support surface 31111 is an inclined plane, so that the support surface 31111 can be set at an obtuse angle with the adapter 20. When the electrode assembly 10 is placed on the support surface 31111, the side of the electrode assembly 10 with the electrode tab 12 is tilted downward toward the adapter 20, so that the electrode tab 12 can abut against the adapter 20.

[0106] The connection methods between the first positioning member 3112 and the supporting member 3111 and the second positioning member 3113 and the supporting member 3111 include but are not limited to bolt connection, pin connection, riveting or welding, etc., and can also be integrally formed.

[0107] Therefore, the first positioning member 3112 and the second positioning member 3113 respectively position the electrode assembly 10, thereby ensuring the accuracy of the relative position between the electrode assembly 10 and the adapter 20.

[0108] In some embodiments, please refer to Figure 2 There are two second positioning members 3113 , and the two second positioning members 3113 are spaced apart along the second direction Y. At least one of the two second positioning members 3113 is connected to the supporting member 3111 in an adjustable manner along the second direction Y.

[0109] In one example, both second positioning members 3113 are adjustably connected to the support member 3111 along the second direction Y. Specifically, optionally, a second positioning member 3113 is slidably connected to each side of the support member 3111 along the second direction Y. The second positioning members 3113 can be slidably connected to the support member 3111 via a guide member such as a guide rod or a guide rail. The second positioning members 3113 can be driven by a linear drive member such as an electric push rod to achieve adjustable position of the second positioning members 3113 relative to the support member 3111 along the second direction Y.

[0110] In another example, a long slot extending along the second direction Y can be provided on the support member 3111, and the second positioning member 3113 is slidingly connected to the support member 3111. The second positioning member 3113 is connected to the support member 3111 through fasteners such as bolts passing through the long slot. By loosening the fasteners, the position of the second positioning member 3113 relative to the support member 3111 can be adjusted.

[0111] Thus, the electrode assemblies 10 of different sizes along the second direction Y are positioned, thereby improving the applicable range of the positioning device 310 .

[0112] In some embodiments, please refer to Figure 2In the second positioning member 3113 connected to the support member 3111 in an adjustable manner along the second direction Y, the second positioning member 3113 is slidingly connected to the support member 3111 along the second direction Y, and the positioning device 310 also includes an adjusting rod, one of the support member 3111 and the second positioning member 3113 is threadedly connected to the adjusting rod, and one of the support member 3111 and the second positioning member 3113 is rotatably connected to the adjusting rod, and the length direction of the adjusting rod is the same as the second direction Y.

[0113] By rotating the adjusting member, the second positioning member 3113 can be moved relative to the supporting member 3111 along the second direction Y, so as to position electrode assemblies 10 of different sizes along the second direction Y. Moreover, the operation by rotating the adjusting member is simple.

[0114] In a specific optional embodiment of the battery cell welding method, please refer to Figure 1 , welding methods include: A positioning device 310 is provided, which has an adapter plate mounting position and an electrode assembly mounting position. The adapter plate mounting position is provided with an electrode assembly mounting position on at least one side along the first direction X. The adapter plate 20 of the electrode cell is placed in the adapter plate mounting position, and the electrode assembly 10 of the battery cell is placed in the electrode assembly mounting position. The electrode assembly mounting position has a supporting surface 31111 for supporting the electrode assembly 10. The supporting surface 31111 is configured to be set at an obtuse angle to the adapter plate 20. The first direction X intersects with the height direction Z of the positioning device 310.

[0115] The support surface 31111 allows the electrode assembly 10 to tilt at a certain angle relative to the adapter plate 20, that is, the first end 111 of the main body 11 of the electrode assembly 10 facing away from the adapter plate 20 is higher than the second end 112 of the main body 11 facing the adapter plate 20. The main body 11 of the electrode assembly 10 refers to the portion connected to the tab 12.

[0116] A pressing member 320 is provided and simultaneously pressed against the pre-pressing regions of the respective tabs 12 of the two electrode assemblies 10. Specifically, a convex arc surface 3231 is provided at each end of the flat surface 3211 of the pressing member 320 along the first direction X. The arc surface 3231 is connected to the flat surface 3211. Pressure is applied to the pressing member 320 so that at least a portion of the flat surface 3211 is simultaneously pressed against the pre-pressing regions of the two electrode assemblies 10, and at least a portion of the arc surface 3231 at different positions is pressed against the pre-pressing regions of the tabs 12 of different electrode assemblies 10. The pre-pressing region is the non-insulating layer region 122 of the tab 12. The dimension of the pre-pressing region is ΔL along the direction from the first end 111 to the second end 112. The dimension of the adapter 20 along the first direction X is L1. ΔL is set to be greater than or equal to 5 mm and less than L1. The first direction X is parallel to the adapter 20 and is the spacing direction between the two electrode assemblies 10. Along the direction from the first end 111 to the second end 112, the minimum dimension from the pre-pressing area to the first end 111 is L2, and the value range of L2 is set to 8mm-11mm. The radius of the arc surface 3231 is r, and the value range of r is set to 0.2mm-0.5mm. The two opposite sides of the main body 11 have a first side surface and a second side surface. When the clamping member 320 presses the tab 12 against the adapter 20, the first side surface is set upward and the second side surface is set downward. The spacing between the first side surface and the second side surface is h, and the angle between the second side surface and the adapter 20 is B. Along the direction from the first end 111 to the second end 112, the minimum distance from the weld mark on the surface of the tab 12 to the main body 11 is W, the size of the tab 12 is L, and the value of r is LWh*cos(B-90°).

[0117] By setting the respective value ranges of r, L2, and △L to the above-mentioned intervals and B satisfying the above-mentioned formula, the arc surface 3231 can be pressed into the pre-pressing area, which can prevent the tab 12 from being over-pressurized or under-pressurized, thereby reducing the redundancy of the tab 12 and the possibility of cold welding, thereby improving the welding quality.

[0118] 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 or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A method for welding a battery cell, characterized in that: include: A positioning device is provided, the positioning device having an adapter plate mounting position and an electrode assembly mounting position, the electrode assembly mounting position being provided on at least one side of the adapter plate mounting position along a first direction, the electrode assembly mounting position having a support surface for supporting the electrode assembly, the support surface being configured to form an obtuse angle with the adapter plate, and the first direction intersecting with a height direction of the positioning device; Placing the adapter sheet of the electrode unit on the adapter sheet installation position, and placing the electrode assembly of the battery unit on the electrode assembly installation position; Provide a clamping piece; Pressing the pressing member on the pre-pressing area of the electrode tab of the electrode assembly so that the electrode tab of the electrode assembly is pressed against the adapter; The tab and the adapter are welded.

2. The welding method according to claim 1, characterized in that Pressing the pressing member against the pre-pressing area of the electrode tab of the electrode assembly includes: The surface of the pressing member facing the electrode tab is set as an outwardly convex arc surface and a flat surface, the arc surface and the flat surface are connected, and the pressing member is arranged in the pre-pressing area so that the arc surface is arranged between the main body of the electrode assembly and the flat surface, and pressure is applied to the pressing member so that at least part of the arc surface and at least part of the flat surface are respectively pressed against the pre-pressing area.

3. The welding method according to claim 2, characterized in that There are two electrode assemblies, which are respectively arranged on both sides of the adapter along the first direction, and the pressing member is simultaneously pressed on the pre-pressing areas of the two electrode assemblies so that the tabs of the two electrode assemblies are respectively in contact with the adapter.

4. The welding method according to claim 3, characterized in that Pressing the pressing member simultaneously on the pre-pressing areas of the two electrode assemblies comprises: The arc surfaces are respectively set at both ends of the plane of the pressing member along the first direction, and pressure is applied to the pressing member so that at least part of the plane is pressed on the pre-pressing areas of the two electrode assemblies at the same time, and at least part of the arc surfaces at different positions are pressed on the pre-pressing areas of different electrode assemblies.

5. The welding method according to claim 3, characterized in that The clamping member includes a first plate body, a second plate body and a bending portion, the first plate body is respectively connected to the bending portion at both ends along the first direction, the bending portion is connected to the second plate body, the first plate body and the second plate body are arranged at an angle, and the bending portion has the arc surface on one side facing the tab.

6. The welding method according to claim 2, characterized in that The radius of the arc surface is r, and the value range of r is set to 0.2mm-0.5mm.

7. The welding method according to any one of claims 2 to 6, characterized in that: The distance between the side of the main body facing away from the positioning device and the support surface is h, the obtuse angle between the support surface and the transition surface is B, the radius of the arc surface is r, the main body has a first end facing away from the adapter plate and a second end facing the adapter plate, along the direction from the first end to the second end, the minimum distance from the weld mark on the surface of the tab to the main body is W, the size of the tab is L, and the value of r is LWh*cos(B-90°).

8. The welding method according to any one of claims 1 to 6, characterized in that: The obtuse angle between the support surface and the transition surface is B, and the value range of B is set to 165°-175°.

9. The welding method according to any one of claims 1 to 6, characterized in that: The electrode tab has an insulating layer region and a non-insulating layer region. The insulating layer region is located between the non-insulating layer region and the main body of the electrode assembly. The insulating layer region has an insulating layer. The pressing member is pressed against the non-insulating layer region.

10. The welding method according to claim 9, characterized in that: Along the first direction, the size of the pre-pressing area is ΔL, and the size of the adapter piece along the first direction is L1. ΔL is set to be greater than or equal to 5 mm and smaller than L1.

11. The welding method according to claim 10, characterized in that: The main body has a first end facing away from the adapter plate and a second end facing the adapter plate. Along the direction from the first end to the second end, the minimum dimension from the pre-pressing area to the first end is L2, and the value range of L2 is set to 8mm-11mm.

12. A welding tool, used in the welding method of a battery cell according to any one of claims 1 to 11, characterized in that: The welding tool comprises: A positioning device having an adapter plate mounting position and an electrode assembly mounting position, the electrode assembly mounting position being provided on at least one side of the adapter plate mounting position along a first direction, the adapter plate mounting position being used to place the adapter plate, the electrode assembly mounting position being used to place the electrode assembly, the electrode assembly mounting position having a support surface for supporting the electrode assembly, the support surface being configured to form an obtuse angle with the adapter plate, the positioning device being used to position the electrode assembly and the adapter plate along a first direction and a second direction, respectively, the first direction being perpendicular to the second direction, and a plane common to the first direction and the second direction intersecting with a height direction of the positioning device; A pressing member is located above the positioning device and is configured to move along the height direction of the positioning device to press the pole piece onto the adapter piece.

13. The welding tool according to claim 12, characterized in that: The clamping member includes a first plate body, a second plate body and a bending portion, the first plate body is connected to the bending portion at both ends along the first direction, the first direction is parallel to the first plate body, the bending portion is connected to the second plate body, the first plate body and the second plate body are arranged at an angle, and the bending portion has a convex arc surface on one side facing the tab.

14. The welding tool according to claim 13, characterized in that: The radius of the arc surface is r, and the value range of r is 0.2mm-0.5mm.

15. The welding tool according to any one of claims 12 to 14, characterized in that: The positioning device comprises: A support assembly includes a support member, a first positioning member and a second positioning member. The support assembly has the electrode assembly mounting position, the upper surface of the support assembly has the support surface, the first positioning member and the second positioning member are respectively arranged on the support member, the first positioning member is used to position the electrode assembly along the first direction, and the second positioning member is used to position the electrode assembly along the second direction.

16. The welding tool according to claim 15, characterized in that: There are two second positioning members, and the two second positioning members are spaced apart along the second direction. At least one of the two second positioning members is adjustably connected to the supporting member along the second direction.

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