Welding piece and welding device for battery welding

Abstract

The invention provides a welding piece for battery welding and a welding device, and belongs to the technical field of welding devices. The welding piece for battery welding comprises a base material made of a conductive material, and the base material is electrically connected with an electrode during welding. A current guide structure is arranged on the base material, and a current path is formed among the multiple layers of tabs or the composite current collector when the current guide structure is welded; the base material is further provided with a temperature sensing assembly, the physical state of the temperature sensing assembly changes within a preset temperature interval, and a temperature feedback signal is output. The welding piece can be used for welding the battery tabs, contact resistance between the tabs (foils) can be reduced or eliminated through the flow guide structure, current conduction during welding is achieved, and therefore the welding quality of the tabs is improved.

Description

Technical Field

[0001] This invention relates to the field of welding equipment technology, and in particular to a welding sheet and welding device for battery welding. Background Technology

[0002] In recent years, with the rapid development of the new energy industry, especially in the fields of power batteries and energy storage, higher requirements have been placed on the performance and manufacturing processes of key conductive components in batteries. Composite current collectors, as a new type of lightweight, high-strength conductive material, have been widely used in fields such as lithium batteries due to their excellent conductivity, good mechanical properties, and lightweight characteristics, for example, as the positive and negative electrodes of lithium batteries. Composite current collectors typically adopt a sandwich structure of "metal layer (such as copper or aluminum) + polymer substrate (such as PET / PP / PI) + metal layer," with the middle polymer layer serving a supporting and insulating function.

[0003] However, this structure also presents significant challenges for multi-layer welding of the tabs. Traditional tab welding processes, such as ultrasonic spot welding, laser welding, or resistance welding, all have obvious bottlenecks when dealing with multi-layer composite current collectors. In particular, resistance welding and its derivative pressure welding processes cannot achieve reliable integrated welding because the polymer substrate in the middle of the composite current collector is non-conductive, and the welding current cannot penetrate the insulating layer. This results in the inability to form an effective current path between the multi-layer tabs, making it difficult to achieve reliable integrated welding.

[0004] Therefore, it is necessary to improve the welding method of existing composite current collectors in order to overcome the shortcomings of the existing technology. Summary of the Invention

[0005] To overcome the problems existing in the related technologies, one of the objectives of this application is to provide a welding sheet for battery welding. This welding sheet can be used for welding battery tabs, and through the current guiding structure, it can reduce or eliminate the contact resistance between the tabs (foil), realize the current conduction during welding, and thus improve the welding quality of the tabs.

[0006] A welding piece for battery welding includes a base material made of a conductive material, which is electrically connected to an electrode during welding. The base material is provided with a raised current guiding structure, which forms a current path between the multilayer tabs or composite current collectors during welding; the base material is also provided with a temperature sensing component, which undergoes a physical state change within a preset temperature range and outputs a temperature feedback signal.

[0007] In a preferred embodiment of this application, the flow guiding structure is a column, sphere, or cone protruding from the surface of the base material; one or more of the column, the sphere, or the cone are provided on the base material.

[0008] In a preferred embodiment of this application, the cone is a cylindrical cone or a pyramidal cone; the height of the cone is 0.1-5mm, and the maximum width of the bottom of the cone is 0.3-5mm.

[0009] In a preferred embodiment of this application, the temperature sensing component includes a temperature-sensing material layer and a signal transmitting element, wherein the temperature-sensing material layer is made of a low-melting-point alloy or a temperature-sensitive color-changing polymer material. One side of the temperature-sensing material layer is connected to the flow-guiding structure, and the opposite side is connected to the signal transmission element; the signal transmission element is a conductive coating, one side of the signal transmission element abuts against the temperature-sensing material layer, and the opposite side is electrically connected to the external welding device.

[0010] In a preferred embodiment of this application, the surface of the flow guiding structure is provided with rough texture, which is any one or a combination of concentric circles, spirals, radial lines or pits.

[0011] The second objective of this application is to provide a welding apparatus, including a welding machine body, wherein the welding machine body is provided with a feeding mechanism, a transfer mechanism, a shaping mechanism and a welding mechanism; The feeding mechanism includes a vibrating feeding plate, which stores welding pieces for battery welding as described above. The shaping mechanism is located on one side of the feeding mechanism and is used to shape the battery tabs. The transfer structure is used to place the welding piece on the welding mechanism, thereby enabling the welding mechanism to weld the battery tabs through the welding piece.

[0012] In a preferred embodiment of this application, the welding mechanism includes a frame, an upper electrode, a lower electrode, and a driving structure. The frame is fixed to the main body of the welding machine, the lower electrode is fixed to one side of the frame, the driving structure is disposed on the frame, the upper electrode is disposed above the lower electrode, and the upper electrode is fixedly connected to the output end of the driving structure. The driving structure drives the upper electrode to move up and down above the lower electrode.

[0013] In a preferred embodiment of this application, the frame is further provided with a tab tape take-up and take-up mechanism, which includes a feed tray, a take-up tray, a guide structure, and an end guide roller; the feed roller and the take-up roller are arranged opposite to each other on both sides of the drive structure, and two end guide rollers are provided, with the two end guide rollers arranged below the drive structure. Two guide structures are provided on the frame, and the two guide structures are respectively located between the feeding tray and an end guide roller, and between the receiving tray and an end guide roller; The feeding tray has a tab tape placed on it. One end of the tab tape passes through the guide structure, the two end guide rollers, and the guide structure extends into the receiving tray.

[0014] In a preferred embodiment of this application, the welding machine body is further provided with a battery moving mechanism, which includes a drive system, a support plate, and a clamp. The drive system includes a first guide rail, a mounting base, a second guide rail, and a lifting drive cylinder; the first guide rail is disposed between the forming mechanism and the welding mechanism, the mounting base is movably disposed on the first guide rail, the second guide rail is vertically fixed on the mounting base, the lifting drive cylinder is disposed on one side of the second guide rail, the support plate is disposed on the second guide rail, and the clamp is detachably disposed on the support plate; the lifting drive cylinder drives the support plate to move up and down on the second guide rail.

[0015] The beneficial effects of this invention are as follows: This invention provides a welding sheet for battery welding. The welding sheet includes a base material made of conductive material, which is electrically connected to the electrodes during welding. A current-guiding structure is provided on the base material, forming a current path between multilayer tabs or composite current collectors during welding. A temperature-sensing component is also provided on the base material, which undergoes a physical state change within a preset temperature range and outputs a temperature feedback signal. This welding sheet can be used for welding battery tabs. In the welding process of multilayer metal foil tabs, there are numerous microscopic voids and oxide films between layers, forming a large amount of accumulated contact resistance. The current applied by conventional welding electrodes is severely hindered by these interfacial resistances, failing to flow evenly and effectively through all interlayer interfaces, leading to welding failure or only surface welding. In the local area where the raised current-guiding structure contacts the foil, the contact resistance is effectively reduced due to pressure concentration. The current preferentially selects this low-resistance path established by the protrusions and penetrating the multilayer foil, thus successfully forming a main current loop, generating concentrated and effective resistance heat, and achieving welding. Furthermore, the resistance heat is highly concentrated at the location of the current-guiding structure, rather than being dispersed over the entire area. This avoids weak welds caused by heat diffusion and prevents overheating from damaging the foil in surrounding non-welded areas, thereby improving the overall weld quality. Furthermore, the temperature-sensing component of this application can detect temperature changes during welding, providing each weld joint with a one-time, on-chip temperature recording tag, enabling direct monitoring of the thermal process at each weld point.

[0016] This application also provides a welding apparatus including the welding sheet described above for battery welding. This apparatus can improve the welding quality of the product by utilizing the welding sheet and has a high degree of automation. When applied to the welding of cylindrical batteries, it can improve the welding quality of the battery tabs and improve the overall product quality of the cylindrical batteries. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a welding piece with a protruding flow guiding structure for battery welding provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of a welding piece with a conical flow guiding structure provided in an embodiment of the present invention for battery welding; Figure 3 This is a schematic diagram of a single flow guiding structure provided on the base material in an embodiment of the present invention; Figure 4 This is a schematic diagram of the rough texture provided in the embodiment of the present invention on the flow guiding structure; Figure 5 This is a schematic diagram showing the temperature sensing component provided in an embodiment of the present invention disposed in the body of the welding sheet; Figure 6 This is a perspective view of the welding apparatus provided in an embodiment of the present invention; Figure 7 This is a front view of the welding apparatus provided in an embodiment of the present invention; Figure 8 This is a schematic diagram of the tab tape take-up and take-down mechanism provided in an embodiment of the present invention being installed on the frame; Figure 9 This is a perspective view of the battery moving mechanism provided in an embodiment of the present invention; Figure 10 This is a schematic diagram of the battery moving mechanism provided in an embodiment of the present invention; Figure 11 This is a schematic diagram showing the direction of current flow during welding using the welding device provided in an embodiment of the present invention.

[0018] Figure label: 1. Base material; 2. Flow guiding structure; 3. Temperature sensing component; 31. Temperature sensing material layer; 32. Signal transmission component; 4. Rough texture; 100. Welding machine body; 110. Feeding mechanism; 120. Transfer mechanism; 130. Shaping mechanism; 140. Battery moving mechanism; 1401. First guide rail; 1402. Second guide rail; 1403. Lifting drive cylinder; 1404. Mounting base; 1405. Bearing plate; 1406. Fixture; 150. Welding mechanism; 1501. Frame; 1502. Lower electrode; 1503. Upper electrode; 1504. Drive structure; 1505. Electrode tape take-up and drop mechanism; 15051. Discharge tray; 15052. Take-up tray; 15053. Guide structure; 15054. End guide roller; 15055. Electrode tape. Detailed Implementation

[0019] Preferred embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While preferred embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0020] In recent years, with the rapid development of the new energy industry, especially in the fields of power batteries and energy storage, higher requirements have been placed on the performance and manufacturing processes of key conductive components in batteries. Composite current collectors, as a new type of lightweight, high-strength conductive material, have been widely used in fields such as lithium batteries due to their excellent conductivity, good mechanical properties, and lightweight characteristics, for example, as the positive and negative electrodes of lithium batteries. Composite current collectors typically adopt a sandwich structure of "metal layer (such as copper or aluminum) + polymer substrate (such as PET / PP / PI) + metal layer," with the middle polymer layer serving a supporting and insulating function.

[0021] However, this structure also presents significant challenges for multi-layer welding of the tabs. Traditional tab welding processes, such as ultrasonic spot welding, laser welding, or resistance welding, all have obvious bottlenecks when dealing with multi-layer composite current collectors. In particular, resistance welding and its derivative pressure welding processes cannot achieve reliable integrated welding because the polymer substrate in the middle of the composite current collector is non-conductive, and the welding current cannot penetrate the insulating layer. This results in the inability to form an effective current path between the multi-layer tabs, making it difficult to achieve reliable integrated welding.

[0022] Based on this, this application provides a welding sheet for battery welding.

[0023] Example 1 like Figures 1-5 As shown, this embodiment provides a welding sheet for battery welding, including a base material 1 made of conductive material, which is electrically connected to the electrode during welding. The base material 1 is provided with a protruding current guiding structure 2, which forms a current path between the multilayer tabs or composite current collectors during welding; the base material 1 is also provided with a temperature sensing component 3, which undergoes a physical state change within a preset temperature range and outputs a temperature feedback signal.

[0024] Specifically, the base material 1 is made of a highly conductive material. The base material 1 of the positive electrode welding piece is made of pure aluminum, and the base material 1 of the negative electrode welding piece is made of T2 copper. When this welding piece is used for welding battery tabs, the thickness of the base material 1 is designed to be adapted according to the number of tab layers or the thickness of the composite current collector (the conventional thickness range is 0.1-0.5mm) to ensure the low resistance characteristics of the base material 1 itself, providing a basic path for current conduction.

[0025] In one embodiment, the temperature sensing component 3 is embedded in the non-welding area of ​​the base material 1 (avoiding the distribution range of the flow guiding structure 2), and is made of shape memory alloy sheet or thermochromic material. Its preset temperature range matches the optimal temperature range for battery welding (180-250℃). If the temperature sensing component 3 uses a shape memory alloy sheet, its initial state is a bent shape. When the welding temperature reaches the preset lower limit (180℃), the alloy sheet recovers its shape and becomes straight, triggering a preset mechanical contact switch and outputting a temperature compliance feedback signal. When the temperature exceeds the preset upper limit (250℃), the alloy sheet deforms again, triggering an alarm signal. If the temperature sensing component 3 uses a thermochromic material, its initial color is white, turning blue when the temperature reaches 180℃ (temperature compliance signal), and turning red when the temperature exceeds 250℃ (over-temperature alarm signal). The feedback signal can be captured by visual recognition or an optical sensor.

[0026] The aforementioned welding sheet for battery welding can be used for welding battery tabs. During the welding process of multi-layer metal foil tabs, numerous microscopic voids and oxide films exist between layers, resulting in significant accumulated contact resistance. The current applied by conventional welding electrodes is severely hindered by these interfacial resistances, preventing it from flowing evenly and effectively through all interlayer interfaces, leading to welding failure or only surface welding. In the localized area where the raised current-guiding structure 2 contacts the foil, the contact resistance is effectively reduced due to pressure concentration. The current preferentially selects this low-resistance path established by the protrusions and traversing the multi-layer foil, thus successfully forming the main current loop, generating concentrated and effective resistance heat, and achieving welding. Furthermore, the resistance heat is highly concentrated at the location of the current-guiding structure 2, rather than being dispersed over the entire area. This avoids weak welding caused by heat diffusion and prevents overheating damage to the surrounding non-welded foil areas, thereby improving the overall welding quality. In addition, the temperature-sensing component 3 of this application can sense temperature changes during welding, providing each weld point with a one-time, on-board temperature recording tag, enabling direct monitoring of the thermal process at each weld point.

[0027] In a specific embodiment, the flow guiding structure 2 is a column, sphere, or cone protruding from the surface of the base material, and one or more of the column, the sphere, or the cone are provided on the base material 1.

[0028] Specifically, the current-guiding structure 2 of this application can be a columnar structure disposed on the base material 1, such as a cylinder, square column, or polygonal column; it can also be a hemispherical or spherical structure protruding on the base material 1; the current-guiding structure 2 can also be a frustum, a truncated cone, or a protruding structure with a cylindrical bottom and a hemispherical top. In practical applications, current-guiding structures 2 with different diameters and heights can be customized according to the number of welding tab layers, for example, columns or spheres of different sizes can be customized according to the number of welding tab layers. The current-guiding structure of this application is integrally processed on the base material 1 (such as aluminum or copper) and has excellent conductivity. When the protruding current-guiding structure 2 is pressed into the foil stack, it forms one or more local, direct metal contact points between multiple layers of foil, providing a current flow path, so that when the current flows through this path, it bypasses most of the poor contact surfaces between the foil layers, greatly reducing the total circuit resistance, allowing a sufficiently large welding current to pass through, and achieving deep fusion. Therefore, the size of a single current-guiding structure 2 can be customized according to the number of welding tab layers required. In one embodiment, the protrusion height of a single flow guide structure 2 can be 0.1-3 mm, and the width of the bottom can be 0.3-2 mm.

[0029] Furthermore, the cone is a cone or a pyramid; the height of the cone is 0.1-5mm, and the maximum width of the bottom of the cone is 0.3-5mm. The core structure of the composite current collector is "metal layer + polymer insulating layer (PET / PP / PI) + metal layer", and the thickness of the intermediate insulating layer is usually 0.01-0.1mm. The cone height of this application is set to 0.1-5mm, which ensures that the cone can penetrate the insulating layer and make full contact with the metal layers on both sides (the minimum height of 0.1mm can cover ultra-thin insulating layer scenarios), while avoiding excessive puncture due to excessive height (such as damage to the current collector substrate or adjacent components); the maximum width of the bottom of 0.3-5mm ensures the contact area between the cone and the metal layer, reduces the contact resistance, and enables stable current conduction, thereby solving the problem of the insulating layer hindering current conduction in traditional welding processes.

[0030] The flow guiding structure 2 is an integrated structure protruding from the surface of the base material 1. It is integrally formed with the base material 1 through milling or stamping processes to ensure structural strength and electrical conductivity continuity.

[0031] For multi-layer electrode welding scenarios, the current guiding structure 2 is designed with arc-shaped cross-section protrusions. The positive electrode welding piece adopts a single protrusion design, while the negative electrode welding piece adopts a concentrated array of multiple protrusions (3-10 protrusions can be selected, arranged in a triangular, rectangular, or spaced array). The protrusion diameter is 2-5mm and the height is 0.3-1mm. By coordinating the protrusions with the electrode welding pressure, the contact resistance between the multi-layer electrodes is reduced. The surface of the protrusions is roughened to form textures. The texture type can be concentric circle, spiral, radial, or pitted, which further increases the interface contact resistance between the protrusions and the electrodes and improves the welding heating efficiency.

[0032] For composite current collector welding scenarios, the current guiding structure 2 is designed as a conical or pyramidal toothed structure with a tooth height of 0.5-10mm and a diameter of 0.2-5mm. Several teeth are evenly distributed in an array, which can pierce the polymer insulating layer (PET / PP / PI) in the middle of the composite current collector and directly establish a current conduction path between the metal layers.

[0033] Taking the welding of multi-layer electrode tabs in lithium batteries as an example, the specific steps of the welding process are as follows: Pre-treatment: Flatten the multi-layer tabs (such as 10-30 layers of aluminum foil or copper foil tabs), pre-press and position the tabs using a shaping fixture, and reserve an area for placing the welding pieces.

[0034] Assembly: Place the positive electrode welding piece and the negative electrode welding piece on the positive and negative end faces of the electrode tab respectively, ensuring that the current guiding structure 2 (protrusion) is in close contact with the electrode tab surface, and the temperature sensing component 3 is exposed outside the welding area for easy signal acquisition.

[0035] Welding operation: Place the assembled electrode tab and welding piece between the upper and lower electrodes of the welding device, start the welding power cabinet, and output a stable current through the transformer. The current forms a conductive path through the upper electrode - multi-layer electrode tab - current guiding structure 2 - base material 1 - lower electrode. The electrode tab and welding piece are fused together by heating with contact resistance. During the welding process, the water circuit assembly can also be used to provide circulating cooling for the electrode head and transformer, and the gas circuit assembly can maintain the electrode pressure stable (0.2-0.4Mpa).

[0036] During the welding process, the temperature of the welding area is fed back in real time through the temperature sensing component 3. If a temperature up to standard signal is received (shape memory alloy sheet is flat / temperature-sensitive material turns blue), the welding parameters are maintained until the welding is completed. If an over-temperature alarm signal is received (shape memory alloy sheet undergoes secondary deformation / temperature-sensitive material turns red), the welding power cabinet automatically adjusts the output current or cuts off the power supply to avoid overheating damage to the tabs or battery materials.

[0037] In one specific embodiment, the temperature sensing component 3 includes a temperature sensing material layer 31 and a signal transmitting element 32, wherein the temperature sensing material layer 31 is made of a low melting point alloy or a temperature-sensitive color-changing polymer material. One side of the temperature-sensing material layer 31 is connected to the flow-guiding structure 2, and the other side is connected to the signal conductor 32; the signal conductor 32 is a conductive coating, one side of the signal conductor 32 abuts against the temperature-sensing material layer 31, and the other side is electrically connected to the external welding device.

[0038] See Figure 4 Furthermore, the surface of the flow guiding structure 2 is provided with rough texture 4, which is any one or a combination of concentric circles, spirals, radial lines or pits.

[0039] The rough texture 4 on the surface of the current-guiding structure 2 increases the interfacial contact area and contact resistance with the foil. Combined with the bump / tooth structure design, this reduces contact resistance between multiple layers of tabs, ensuring smooth current conduction. It also improves interfacial heating efficiency, concentrating welding heat in the fusion zone and shortening welding time. Compared to a textureless design, this increases welding strength and effectively prevents incomplete or false welds. The various combinations of rough texture 4 are suitable for different welding scenarios: for example, a concentric circle + pit composite texture retains the uniform pressure distribution advantage of the concentric circle texture while enhancing interfacial friction through the pits, preventing relative slippage between the connecting piece and the foil during welding, making it particularly suitable for multi-layer tab welding; a spiral + radial texture further improves the uniform heat distribution during composite current collector welding, preventing localized overheating.

[0040] Example 2 like Figures 6-11 As shown, this embodiment provides a welding device, including a welding machine body 100, on which a feeding mechanism 110, a transfer mechanism 120, a shaping mechanism 130 and a welding mechanism 150 are provided; The feeding mechanism 110 includes a vibrating feeding plate, which stores welding pieces for battery welding as described above. The shaping mechanism 130 is located on one side of the feeding mechanism 110 and is used to shape the battery tabs. The transfer structure is used to place the welding piece on the welding mechanism 150, thereby enabling the welding mechanism 150 to weld the battery tabs through the welding piece.

[0041] Specifically, the welding mechanism 150 includes a frame 1501, an upper electrode 1503, a lower electrode 1502, and a drive structure 1504. The frame 1501 is fixed to the welding machine body 100, the lower electrode 1502 is fixed to one side of the frame 1501, the drive structure 1504 is disposed on the frame 1501, the upper electrode 1503 is disposed above the lower electrode 1502, and the upper electrode 1503 is fixedly connected to the output end of the drive structure 1504. The drive structure 1504 drives the upper electrode 1503 to move up and down above the lower electrode 1502. Specifically, the shape of the opposite surfaces of the upper electrode 1503 and the lower electrode 1502 matches the positioning groove of the lower electrode 1502. The drive structure 1504 can drive the upper electrode 1503 to move precisely in the vertical direction, realizing the pressing and welding of the welding piece and the electrode tab. Furthermore, the frame 1501 is also provided with a tab tape take-up and take-up mechanism 1505, which includes a feed tray 15051, a take-up tray 15052, a guide structure 15053, and an end guide roller 15054; the feed roller and the take-up roller are arranged opposite to each other on both sides of the drive structure 1504, and two end guide rollers 15054 are provided, and the two end guide rollers 15054 are arranged below the drive structure 1504; Two guide structures 15053 are provided on the frame 1501, and the two guide structures 15053 are respectively located between the feeding tray 15051 and an end guide roller 15054, and between the receiving tray 15052 and an end guide roller 15054. The feeding tray 15051 has a tab tape 15055 placed on it. One end of the tab tape 15055 passes through the guide structure 15053 and the two end guide rollers 15054 in sequence. The guide structure 15053 extends into the receiving tray 15052.

[0042] Furthermore, the welding machine body 100 is also provided with a battery moving mechanism 140, which includes a drive system, a support plate 1405 and a clamp 1406. The drive system includes a first guide rail 1401, a mounting base 1404, a second guide rail 1402, and a lifting drive cylinder 1403. The first guide rail 1401 is disposed between the forming mechanism 130 and the welding mechanism 150. The mounting base 1404 is movably disposed on the first guide rail 1401. The second guide rail 1402 is vertically fixed on the mounting base 1404. The lifting drive cylinder 1403 is disposed on one side of the second guide rail 1402. The support plate 1405 is disposed on the second guide rail 1402. The clamp 1406 is detachably disposed on the support plate 1405. The lifting drive cylinder 1403 drives the support plate 1405 to move up and down on the second guide rail 1402.

[0043] The electrode tab welding process for this device is as follows: The positive / negative electrode welding sheets to be welded are placed in batches into the vibrating feeding tray. The tab tape 15055 is installed onto the feeding tray 15051 and the tape is threaded through. The battery to be welded is fixed on the clamp 1406 of the battery moving mechanism 140.

[0044] The drive system of the battery moving mechanism 140 drives the mounting base 1404 to move along the first guide rail 1401 to above the shaping mechanism 130. The lifting drive cylinder 1403 drives the support plate 1405 to descend, aligning the battery tabs with the lower shaping mold. The shaping drive cylinder drives the upper shaping mold to press down, pre-pressing and shaping the tabs for 10-15 seconds. After eliminating the stacking gaps, the upper shaping mold is reset.

[0045] The vibrating feeding tray conveys the welding pieces in an orderly manner to the end of the discharge guide rail through vibration. The pneumatic gripper of the transfer mechanism 120 holds the welding pieces, and the lateral movement module drives the pneumatic gripper to move above the positioning groove of the lower electrode 1502 of the welding mechanism 150, so as to accurately place the welding pieces in the positioning groove.

[0046] The battery moving mechanism 140 drives the mounting base 1404 to move along the first guide rail 1401 to the welding mechanism 150. The lifting drive cylinder 1403 drives the carrier plate 1405 to descend, placing the shaped electrode tab onto the welding piece of the lower electrode 1502. The clamp 1406 keeps the battery fixed, ensuring that the electrode tab and the welding piece are precisely aligned.

[0047] The electrode tape take-up and take-down mechanism 1505 is activated, and the take-up tray 15052 drives the electrode tape 15055 to move to the welding area while adhering to the upper surface of the electrode. The drive structure 1504 drives the upper electrode 1503 to descend, pressing the electrode and welding piece between the lower electrode 1502 and the upper electrode 1503. The welding power cabinet outputs current to the upper electrode 1503 and the lower electrode 1502 through the transformer. The current forms a conductive path through the "upper electrode 1503-electrode-welding piece current guiding structure 2-lower electrode 1502", and the electrode and welding piece are fused by the heating of the contact resistance. During the welding process, the water circuit component can also provide circulating cooling for the upper electrode 1503, the lower electrode 1502 and the transformer. The temperature sensing component 3 provides real-time feedback of the temperature signal. If the temperature is abnormal, the control system automatically adjusts the current or stops the machine.

[0048] After welding is completed, the upper electrode 1503 is reset, the tab tape take-up and take-down mechanism 1505 collects the used tape, the battery moving mechanism 140 drives the support plate 1405 to rise and move along the first guide rail 1401 to the unloading area, the clamp 1406 is released, and the battery unloading is completed; all mechanisms are reset and the next welding cycle begins.

[0049] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings. In the description of this application, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this application; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0050] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0051] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, these terms have no special meaning and therefore should not be construed as limiting the scope of protection of this application. The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A welding sheet for battery welding, characterized in that: Includes a base material made of conductive material, which is electrically connected to the electrodes during welding; The base material is provided with a raised current guiding structure, which forms a current path between the multilayer tabs or composite current collectors during welding; the base material is also provided with a temperature sensing component, which undergoes a physical state change within a preset temperature range and outputs a temperature feedback signal.

2. The welding sheet for battery welding according to claim 1, characterized in that: The flow guiding structure is a column, sphere, or cone protruding from the surface of the base material; one or more of the column, sphere, or cone are provided on the base material.

3. The welding sheet for battery welding according to claim 2, characterized in that: The cone is a circular cone or a pyramid; the height of the cone is 0.1-5mm, and the maximum width of the bottom of the cone is 0.3-5mm.

4. The welding sheet for battery welding according to any one of claims 1-3, characterized in that: The temperature sensing component includes a temperature sensing material layer and a signal transmission element. The temperature sensing material layer is made of a low melting point alloy or a temperature-sensitive color-changing polymer material. One side of the temperature-sensing material layer is connected to the flow-guiding structure, and the opposite side is connected to the signal transmission element; the signal transmission element is a conductive coating, one side of the signal transmission element abuts against the temperature-sensing material layer, and the opposite side is electrically connected to the external welding device.

5. The welding sheet for battery welding according to any one of claims 1-3, characterized in that: The surface of the flow guiding structure is provided with rough texture, which can be any one or a combination of concentric circles, spirals, radial lines or pits.

6. A welding apparatus, characterized in that: The welding machine includes a main body, which is equipped with a feeding mechanism, a transfer mechanism, a shaping mechanism, and a welding mechanism. The feeding mechanism includes a vibrating feeding plate, which stores welding pieces for battery welding as described in any one of claims 1-5. The shaping mechanism is located on one side of the feeding mechanism and is used to shape the battery tabs. The transfer structure is used to place the welding piece on the welding mechanism, thereby enabling the welding mechanism to weld the battery tabs through the welding piece.

7. The welding apparatus according to claim 6, characterized in that: The welding mechanism includes a frame, an upper electrode, a lower electrode, and a drive structure. The frame is fixed on the main body of the welding machine, the lower electrode is fixed on one side of the frame, the drive structure is disposed on the frame, the upper electrode is disposed above the lower electrode, and the upper electrode is fixedly connected to the output end of the drive structure. The drive structure drives the upper electrode to move up and down above the lower electrode.

8. The welding apparatus according to claim 7, characterized in that: The frame is also provided with a tab tape take-up and take-up mechanism, which includes a feed tray, a take-up tray, a guide structure and an end guide roller; the feed roller and the take-up roller are arranged opposite to each other on both sides of the drive structure, and two end guide rollers are provided, with the two end guide rollers arranged below the drive structure. Two guide structures are provided on the frame, and the two guide structures are respectively located between the feeding tray and an end guide roller, and between the receiving tray and an end guide roller; The feeding tray has a tab tape placed on it. One end of the tab tape passes through the guide structure, the two end guide rollers, and the guide structure extends into the receiving tray.

9. The welding apparatus according to claim 8, characterized in that: The welding machine body is also equipped with a battery moving mechanism, which includes a drive system, a support plate, and a clamp. The drive system includes a first guide rail, a mounting base, a second guide rail, and a lifting drive cylinder; the first guide rail is disposed between the forming mechanism and the welding mechanism, the mounting base is movably disposed on the first guide rail, the second guide rail is vertically fixed on the mounting base, the lifting drive cylinder is disposed on one side of the second guide rail, the support plate is disposed on the second guide rail, and the clamp is detachably disposed on the support plate; the lifting drive cylinder drives the support plate to move up and down on the second guide rail.

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