A welding sheet and a welding device for battery welding

Abstract

The application provides a welding sheet and a welding device for battery welding, and belongs to the technical field of welding devices. The welding sheet for battery welding comprises a base material made of a conductive material, which is electrically connected with an electrode during welding. A flow guide structure is arranged on the base material, which forms a current path between multiple layers of tabs or composite current collectors during welding. A temperature sensing assembly is also arranged on the base material, which changes in physical state within a preset temperature range and outputs a temperature feedback signal. The welding sheet can be used for welding of battery tabs, and the flow guide structure can reduce or eliminate the contact resistance between the tabs (foil materials), realize current conduction during welding, and thus improve the welding quality of the tabs.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of welding devices, in particular to a welding sheet for battery welding and a welding device. BACKGROUND

[0002] In recent years, with the rapid development of new energy industry, especially power batteries and energy storage fields, higher requirements have been put forward for the performance and manufacturing process of key conductive components of batteries. As a new type of lightweight and high-strength conductive material, composite current collector has been widely used in the field of lithium batteries due to its excellent conductivity, good mechanical properties and light weight, etc., such as being used as positive and negative electrodes of lithium batteries. The composite current collector usually adopts a sandwich structure of "metal layer (such as copper or aluminum) + high molecular substrate (such as PET / PP / PI) + metal layer", and the high molecular layer in the middle plays a supporting and insulating role.

[0003] However, this structure also brings significant challenges to the multi-layer welding of the tab. 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. Especially resistance welding and its derivative pressure fusion welding process, due to the non-conductive high molecular substrate in the middle of the composite current collector, the welding current cannot penetrate the insulating layer, resulting 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 existing welding method of the composite current collector to overcome the defects of the prior art. SUMMARY

[0005] To overcome the problems in the related art, one of the purposes of the present application is to provide a welding sheet for battery welding, which can be used for welding of battery tabs, and can reduce or eliminate the contact resistance between the tabs (foil) through the current guide structure, realize the current conduction during welding, and improve the welding quality of the tabs.

[0006] A welding sheet for battery welding, comprising a base material made of conductive material, which is electrically connected with an electrode during welding;

[0007] A protruding current guide structure is provided on the base material, which forms a current path between the multi-layer tabs or the composite current collector during welding; a temperature sensing assembly is also provided on the base material, which changes its physical state within a preset temperature range and outputs a temperature feedback signal.

[0008] In the preferred technical solution of the present application, the current guide structure is a column, a sphere or a cone protruding from the surface of the base material; one or more columns, spheres or cones are provided on the base material.

[0009] In the preferable technical scheme of the present application, the cone is a circular cone or a pyramid; the height of the cone is 0.1-5 mm, and the maximum width of the bottom of the cone is 0.3-5 mm.

[0010] In the preferable technical scheme of the present application, the temperature sensing component comprises a temperature sensing material layer and a signal conducting element, and the temperature sensing material layer is made of a low-melting alloy or a temperature sensing color-changing polymer material.

[0011] One side of the temperature sensing material layer is connected with the flow guiding structure, and the other side opposite to the one side is connected with the signal conducting element; the signal conducting element is a conductive coating, one side of the signal conducting element is abutted with the temperature sensing material layer, and the other side opposite to the one side is electrically connected with an external welding device.

[0012] In the preferable technical scheme of the present application, the surface of the flow guiding structure is provided with rough lines, and the rough lines are in any one or a combination of a concentric circle type, a spiral type, a radial line type or a pit type.

[0013] The second object of the present application is to provide a welding device, which comprises a welding machine main body, and an upper feeding mechanism, a transferring mechanism, a shaping mechanism and a welding mechanism are arranged on the welding machine main body.

[0014] The upper feeding mechanism comprises a vibrating upper feeding disc, and the vibrating upper feeding disc is used for storing the welding sheet for battery welding.

[0015] The shaping mechanism is arranged on one side of the upper feeding mechanism, and is used for shaping the battery tab.

[0016] The transferring mechanism is used for placing the welding sheet on the welding mechanism, so that the welding mechanism can weld the battery tab through the welding sheet.

[0017] In the preferable technical scheme of the present application, the welding mechanism comprises a rack, an upper electrode, a lower electrode and a driving structure, the rack is fixed on the welding machine main body, the lower electrode is fixed on one side of the rack, the driving structure is arranged on the rack, the upper electrode is arranged above the lower electrode, the upper electrode is fixedly connected with the output end of the driving structure, and the driving structure drives the upper electrode to move up and down above the lower electrode.

[0018] In the preferable technical scheme of the present application, the rack is further provided with a tab adhesive tape feeding and winding mechanism, the tab adhesive tape feeding and winding mechanism comprises a feeding disc, a winding disc, a guide structure and end guide rollers, the feeding disc and the winding disc are arranged on the two sides of the driving structure in opposition, and two end guide rollers are arranged below the driving structure.

[0019] The guide structure is arranged on the rack in two, and the two guide structures are respectively arranged between the feeding disc and one end guide roller and between the collecting disc and one end guide roller.

[0020] The feeding disc is provided with a tab tape, and one end of the tab tape sequentially penetrates the guide structure, the two end guide rollers and the guide structure into the collecting disc.

[0021] In the preferred technical solution of the present application, the welding machine body is further provided with a battery moving mechanism, the battery moving mechanism comprising a driving system, a bearing plate and a clamp;

[0022] The driving system comprises a first guide rail, a mounting seat, a second guide rail and a lifting driving cylinder; the first guide rail is arranged between the shaping mechanism and the welding mechanism; the mounting seat is movably arranged on the first guide rail; the second guide rail is vertically fixed on the mounting seat; the lifting driving cylinder is arranged on one side of the second guide rail; the bearing plate is arranged on the second guide rail; and the clamp is detachably arranged on the bearing plate; the lifting driving cylinder drives the bearing plate to lift on the second guide rail.

[0023] The present application has the following advantages:

[0024] The welding sheet for battery welding provided by the present application comprises a base material made of conductive material, which is electrically connected with an electrode during welding. A current guide structure is arranged on the base material, which forms a current path between the multi-layer tabs or the composite current collectors during welding. A temperature sensing assembly is also arranged on the base material, which changes its physical state within a preset temperature range and outputs a temperature feedback signal. The welding sheet can be used for welding battery tabs. During the welding process of multi-layer metal foil tabs, there are a large number of micro voids and oxide films between the layers, forming a large amount of accumulated contact resistance. The current applied by the conventional welding electrode is severely hindered by these interface resistances, and cannot uniformly and effectively flow through all the interlayer interfaces, resulting in welding failure or only surface welding. The local area where the protruding current guide structure contacts the foil material has a reduced contact resistance due to the concentrated pressure. The current will preferentially choose this low-resistance path established by the protruding point and penetrate through the multi-layer foil, thereby successfully forming a main current loop and generating concentrated and effective resistance heat to achieve welding. Moreover, the resistance heat is highly concentrated at the location of the current guide structure, rather than being dispersed over the entire area. This avoids the welding being not firm due to heat diffusion, and prevents overheating from damaging the foil material in the surrounding non-welding area, thereby improving the overall welding quality. In addition, the temperature sensing assembly of the present application can sense the temperature change during welding, providing a piece-by-piece and one-time temperature record label for each welding point, and realizing direct monitoring of the thermal process of each welding point.

[0025] The application also provides a welding device comprising the welding sheet for battery welding, which can improve the welding quality of products, has high automation degree, is applied to the welding of cylindrical batteries, can improve the welding quality of the battery tab, and improves the overall product quality of the cylindrical battery. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 FIG. 1 is a schematic view of a welding sheet for battery welding with a convex point as a flow guide structure according to an embodiment of the application;

[0027] Figure 2 FIG. 2 is a schematic view of a welding sheet for battery welding with a cone as a flow guide structure according to an embodiment of the application;

[0028] Figure 3 FIG. 3 is a schematic view of a welding sheet with a single flow guide structure on a base material according to an embodiment of the application;

[0029] Figure 4 FIG. 4 is a schematic view of a welding sheet with rough lines on a flow guide structure according to an embodiment of the application;

[0030] Figure 5 FIG. 5 is a schematic view of a temperature sensing assembly arranged in a base material of a welding sheet according to an embodiment of the application;

[0031] Figure 6 FIG. 6 is a perspective view of a welding device according to an embodiment of the application;

[0032] Figure 7 FIG. 7 is a front view of a welding device according to an embodiment of the application;

[0033] Figure 8 FIG. 8 is a schematic view of a tab adhesive tape winding and unwinding mechanism arranged on a rack according to an embodiment of the application;

[0034] Figure 9 FIG. 9 is a perspective view of a battery moving mechanism according to an embodiment of the application;

[0035] Figure 10 FIG. 10 is a schematic view of a battery moving mechanism according to an embodiment of the application;

[0036] Figure 11 FIG. 11 is a schematic view of the flow direction of current when a welding device is welding according to an embodiment of the application.

[0037] REFERENCE SIGNS:

[0038] 1, base material; 2, flow guide structure; 3, temperature sensing assembly; 31, temperature sensing material layer; 32, signal transmission element; 4, rough texture; 100, welding machine main 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 seat; 1405, bearing plate; 1406, clamp; 150, welding mechanism; 1501, rack; 1502, lower electrode; 1503, upper electrode; 1504, drive structure; 1505, tab tape winding and unwinding mechanism; 15051, unwinding disc; 15052, winding disc; 15053, guide structure; 15054, end guide roller; 15055, tab tape. DETAILED DESCRIPTION

[0039] Preferred embodiments of the present application will be described in greater detail below with reference to the accompanying drawings. While preferred embodiments of the present application are shown in the drawings, it is understood that the present application can be carried out in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that this application will be thorough and complete, and will fully convey the scope of the application to those skilled in the art.

[0040] In recent years, with the rapid development of new energy industry, especially power batteries and energy storage fields, higher requirements have been put forward for the performance and manufacturing process of key conductive components of batteries. As a new type of lightweight and high-strength conductive material, composite current collector has been widely used in the field of lithium batteries and other fields, such as being used as positive and negative electrodes of lithium batteries. The composite current collector usually adopts a sandwich structure of "metal layer (such as copper or aluminum) + polymer substrate (such as PET / PP / PI) + metal layer", and the polymer layer in the middle plays a supporting and insulating role.

[0041] However, this structure also brings significant challenges to the multi-layer welding of the tab. 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. Especially resistance welding and its derivative pressure fusion welding process, because the polymer substrate in the middle of the composite current collector is not conductive, the welding current cannot penetrate the insulating layer, resulting in the inability to form an effective current path between the multi-layer tabs, making it difficult to achieve reliable integrated welding.

[0042] Based on this, the present application provides a welding sheet for battery welding.

[0043] Example 1

[0044] As Figures 1-5As shown, the welding tab for battery welding provided by the embodiment includes a base material 1 made of conductive material, which is electrically connected with the electrode during welding;

[0045] The base material 1 is provided with a raised flow guide structure 2, which forms a current path between the multi-layer tabs or the composite current collector during welding; the base material 1 is also provided with a temperature sensing assembly 3, which changes in physical state within a preset temperature range and outputs a temperature feedback signal.

[0046] Specifically, the base material 1 is made of high-conductive material, wherein the base material 1 of the positive welding tab is made of pure aluminum material, and the base material 1 of the negative welding tab is made of T2 red copper material. When the welding tab is used for battery tab welding, the thickness of the base material 1 is designed according to the number of layers of the welded tab or the thickness of the composite current collector (the conventional thickness range is 0.1-0.5mm), which ensures the low resistance characteristics of the base material 1 itself and provides a basic path for current conduction.

[0047] In an embodiment, the temperature sensing assembly 3 is embedded in the non-welding area of the base material 1 (avoiding the distribution range of the flow guide structure 2) and is made of shape memory alloy sheet or temperature-sensitive color-changing material, and its preset temperature range matches the optimal temperature range (180-250℃) of battery welding. If the temperature sensing assembly 3 is made of shape memory alloy sheet, its initial state is curved, when the welding temperature reaches the preset lower limit (180℃), the alloy sheet changes to flat state and triggers the preset mechanical contact switch, outputting the temperature compliance feedback signal; when the temperature exceeds the preset upper limit (250℃), the alloy sheet deforms again and triggers the alarm signal. If the temperature sensing assembly 3 is made of temperature-sensitive color-changing material, its initial color is white, which changes to blue (temperature compliance signal) when the temperature reaches 180℃, and changes to red (over-temperature alarm signal) when the temperature exceeds 250℃, which can be captured by visual recognition or optical sensor to capture the feedback signal.

[0048] The welding tab for battery welding described above can be used for welding of battery tabs. In the process of welding multi-layer metal foil tabs, there are a large number of micro voids and oxide films between the layers, forming a large amount of cumulative contact resistance. The current applied by the conventional welding electrode is severely hindered by these interface resistances and cannot uniformly and effectively flow through all the interlayer interfaces, resulting in welding failure or only surface welding. The local area where the protruding flow guide structure 2 contacts the foil material has a reduced contact resistance due to pressure concentration. The current will preferentially choose this low-resistance path established by the protrusion through the multi-layer foil, thereby successfully forming the main current loop and generating concentrated and effective resistance heat to achieve welding. Moreover, the resistance heat is highly concentrated at the location of the flow guide structure 2, rather than being dispersed over the entire area. This avoids the welding being not firm due to heat diffusion and prevents overheating from damaging the foil material in the surrounding non-welding area, thereby improving the overall welding quality. In addition, the temperature sensing assembly 3 of the present application can sense the temperature change during welding, providing a piece-by-piece, one-time temperature record label for each welding point, and achieving direct monitoring of the thermal process of each welding point.

[0049] In a specific embodiment, the flow guide structure 2 is a column, sphere or cone protruding from the surface of the base material, and the column, sphere or cone is provided with one or more on the base material 1.

[0050] Specifically, the flow guide structure 2 of the present application can be a columnar structure such as a cylinder, a square column, a polygonal column provided on the base material 1, or a hemispherical or spherical structure protruding from the base material 1. The flow guide structure 2 can also be a prism, a circular truncated cone or a protruding structure with a cylindrical bottom and a hemispherical top. In actual applications, flow guide structures 2 of different diameters and heights can be customized according to the number of layers of the tab to be welded, such as columnar structures and spherical structures of different sizes according to the number of layers of the tab to be welded. The flow guide structure of the present application is integrally processed on the base material 1 (such as aluminum or copper) and has excellent electrical conductivity. When the protruding flow guide structure 2 is pressed into the foil stack, it forms one or more local and direct metal contact points between the multi-layer foils, providing a flow path for the current, so that the current flows through the path while bypassing most of the poor contact surfaces between the foil layers, greatly reducing the total resistance of the loop, allowing a large enough welding current to pass through and achieving deep fusion. Therefore, the size of a single flow guide structure 2 can be customized according to the number of layers of the tab to be welded. In one embodiment, the protruding 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.

[0051] Further, the cone is a circular cone or a pyramid; the height of the cone is 0.1-5 mm, and the maximum width of the bottom of the cone is 0.3-5 mm. The core structure of the composite current collector is "metal layer + polymer insulating layer (PET / PP / PI) + metal layer", and the thickness of the middle insulating layer is usually 0.01-0.1 mm. The height of the cone in the present application is set to 0.1-5 mm, which not only ensures that the cone can penetrate the insulating layer and fully contact the two metal layers (the minimum height of 0.1 mm can cover the ultra-thin insulating layer scenario), but also avoids excessive piercing (such as damaging the current collector substrate or adjacent components) caused by excessive height; the maximum width of the bottom is 0.3-5 mm, which ensures the contact area of the cone and the metal layer, reduces the contact resistance, and enables stable conduction of the current, thereby solving the problem of current conduction hindered by the insulating layer in the traditional welding process.

[0052] The flow guide structure 2 is an integrated structure protruding from the surface of the base material 1, and is integrally formed with the base material 1 by milling or stamping process, ensuring the structural strength and electrical continuity.

[0053] For the multi-layer tab welding scene, the flow guide structure 2 is designed as an arc-shaped cross-section protrusion, the positive welding tab adopts a single protrusion design, and the negative welding tab adopts a multiple protrusion centralized array distribution (optionally 3-10 protrusions arranged in a triangular, rectangular or spaced array), the protrusion diameter is 2-5 mm and the height is 0.3-1 mm, which reduces the contact resistance between the multi-layer tabs through the cooperation of the protrusion and the electrode welding pressure; the protrusion surface is roughened to form a pattern, and the pattern type can be selected as concentric circle, spiral, radial or dimple, which further increases the interface contact resistance between the protrusion and the tab and improves the welding heating efficiency.

[0054] For the composite current collector welding scene, the flow guide structure 2 is designed as a cone or pyramid tooth structure, the tooth height is 0.5-10 mm and the diameter is 0.2-5 mm, and a plurality of 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 to directly establish a current conduction path between the metal layers.

[0055] Taking the multi-layer tab welding of a lithium battery as an example, the specific steps of the welding process of the welding tab are as follows:

[0056] Preprocessing: arrange and flatten the multi-layer tabs (such as 10-30 layers of aluminum foil or copper foil tabs), and pre-press and position the tabs through a shaping tool to reserve a welding tab placement area.

[0057] Assembly: place the positive and negative welding tabs on the positive and negative end surfaces of the tabs, respectively, to ensure that the flow guide structure 2 (protrusion) is tightly attached to the surface of the tab, and the temperature sensing component 3 is exposed outside the welding area for easy signal collection.

[0058] Welding operation: place the assembled tab and welding sheet between the upper and lower electrodes of the welding device, start the welding power cabinet, output stable current through the transformer, the current forms a conduction path through the upper electrode-multilayer tab-conductive structure 2-parent material 1-lower electrode, and the contact resistance is used to heat to realize the fusion welding of the tab and the welding sheet; during the welding process, the electrode head and the transformer can also be provided with circulating cooling by using the waterway assembly, and the electrode pressure is maintained stable (0.2-0.4 Mpa) by using the gas path assembly.

[0059] During the welding process, the temperature of the welding area is fed back in real time through the temperature sensing assembly 3, if the temperature reaches the standard signal (shape memory alloy sheet flat / warm sensitive material turns blue), the welding parameters are continuously maintained until the welding is completed; if the over-temperature alarm signal (shape memory alloy sheet deforms twice / warm sensitive material turns red) is received, the welding power cabinet automatically adjusts the output current or cuts off the power supply to avoid over-temperature damage to the tab or the battery material.

[0060] In a specific embodiment, the temperature sensing assembly 3 includes a temperature sensing material layer 31 and a signal conducting element 32, and the temperature sensing material layer 31 is made of a low-melting-point alloy or a temperature-sensitive color-changing high-molecular material;

[0061] One side of the temperature sensing material layer 31 is connected with the conductive structure 2, and the other side opposite to the one side is connected with the signal conducting element 32; the signal conducting element 32 is a conductive coating, one side of the signal conducting element 32 is connected with the temperature sensing material layer 31, and the other side opposite to the one side is connected with the external welding device.

[0062] Referring to Figure 4 Further, the surface of the conductive structure 2 is provided with rough lines 4, and the rough lines 4 are any one or a combination of concentric circle type, spiral type, radial type or pit type.

[0063] The rough lines 4 on the surface of the conductive structure 2 increase the interface contact area and the contact resistance with the foil, and cooperate with the structure design of the convex points / teeth, on the one hand, reduce the contact resistance between the multilayer tabs, and ensure smooth conduction of the current; on the other hand, improve the interface heating efficiency, so that the welding heat is concentrated in the fusion area, the welding time is shortened, compared with the design without lines, the welding strength can be improved, and false welding and false welding can be effectively avoided. The multi-type combination design of the rough lines 4 is suitable for different welding scenes: for example, concentric circle + pit composite lines, which not only retains the advantage of uniform pressure distribution of concentric circle lines, but also enhances the interface friction force through pits to prevent relative sliding of the connecting sheet and the foil during welding, and is especially suitable for multilayer tab welding; the spiral + radial type lines can further improve the uniformity of heat dispersion during composite current collector welding, and avoid local overheating.

[0064] Example 2

[0065] As Figures 6-11As shown, the embodiment provides a welding device, which comprises a welding machine body 100, wherein an upper feeding mechanism 110, a transfer mechanism 120, a shaping mechanism 130 and a welding mechanism 150 are arranged on the welding machine body 100;

[0066] The upper feeding mechanism 110 comprises a vibrating upper feeding disc, wherein the welding sheet for welding the battery as described above is stored in the vibrating upper feeding disc;

[0067] The shaping mechanism 130 is located on one side of the upper feeding mechanism 110 and is used for shaping the battery tab;

[0068] The transfer structure is used for placing the welding sheet on the welding mechanism 150, so that the welding mechanism 150 can weld the battery tab through the welding sheet.

[0069] Specifically, the welding mechanism 150 comprises a rack 1501, an upper electrode 1503, a lower electrode 1502 and a driving structure 1504, the rack 1501 is fixed on the welding machine body 100, the lower electrode 1502 is fixed on one side of the rack 1501, the driving structure 1504 is arranged on the rack 1501, the upper electrode 1503 is arranged above the lower electrode 1502, and the upper electrode 1503 is fixedly connected with the output end of the driving structure 1504, and the driving structure 1504 drives the upper electrode 1503 to move up and down above the lower electrode 1502. Specifically, the shape of the opposite surface of the upper electrode 1503 and the lower electrode 1502 matches the positioning groove of the lower electrode 1502, the driving structure 1504 can drive the upper electrode 1503 to move accurately in the vertical direction, so as to realize the pressing and welding of the welding sheet and the tab

[0070] Further, the rack 1501 is further provided with a tab adhesive tape feeding and winding mechanism 1505, the tab adhesive tape feeding and winding mechanism 1505 comprises a feeding disc 15051, a winding disc 15052, a guide structure 15053 and a terminal guide roller 15054; the feeding disc and the winding disc are oppositely arranged on both sides of the driving structure 1504, and two terminal guide rollers 15054 are arranged below the driving structure 1504;

[0071] The guide structure 15053 is arranged on the rack 1501 in two, and the two guide structures 15053 are respectively located between the feeding disc 15051 and one terminal guide roller 15054 and between the winding disc 15052 and one terminal guide roller 15054;

[0072] The feeding tray 15051 is provided with a tab tape 15055, one end of the tab tape 15055 sequentially passes through the guide structure 15053, two end guide rollers 15054, and the guide structure 15053 extends into the receiving tray 15052.

[0073] Further, the welding machine body 100 is further provided with a battery moving mechanism 140, the battery moving mechanism 140 comprises a driving system, a bearing plate 1405, and a clamp 1406.

[0074] The driving system comprises a first guide rail 1401, a mounting seat 1404, a second guide rail 1402, and a lifting driving cylinder 1403; the first guide rail 1401 is arranged between the shaping mechanism 130 and the welding mechanism 150, the mounting seat 1404 is movably arranged on the first guide rail 1401, the second guide rail 1402 is vertically fixed on the mounting seat 1404, the lifting driving cylinder 1403 is arranged on one side of the second guide rail 1402, the bearing plate 1405 is arranged on the second guide rail 1402, and the clamp 1406 is detachably arranged on the bearing plate 1405; the lifting driving cylinder 1403 drives the bearing plate 1405 to ascend and descend on the second guide rail 1402.

[0075] The device performs tab welding as follows:

[0076] Batch the positive / negative tab to be welded into the vibration feeding tray, install the tab tape 15055 to the feeding tray 15051 and complete the tape setting, and fix the battery to be welded on the clamp 1406 of the battery moving mechanism 140.

[0077] The driving system of the battery moving mechanism 140 drives the mounting seat 1404 to move along the first guide rail 1401 to above the shaping mechanism 130, the lifting driving cylinder 1403 drives the bearing plate 1405 to descend, and the battery tab is aligned with the shaping lower mold; the shaping driving cylinder drives the shaping upper mold to press down, and the tab is pre-pressed and shaped for 10-15 seconds, after eliminating the stacking gap, the shaping upper mold is reset.

[0078] The vibration feeding tray orderly delivers the tab to the end of the discharging guide rail through vibration, the pneumatic clamping jaw of the transfer mechanism 120 clamps the tab, the horizontal moving module drives the pneumatic clamping jaw to move above the lower electrode 1502 positioning groove of the welding mechanism 150, and the tab is accurately placed in the positioning groove.

[0079] The battery moving mechanism 140 drives the mounting seat 1404 to move along the first guide rail 1401 to the welding mechanism 150, the lifting driving cylinder 1403 drives the bearing plate 1405 to descend, the shaped tab is placed on the welding sheet of the lower electrode 1502, and the clamp 1406 fixes the battery to ensure the accurate alignment of the tab and the welding sheet.

[0080] The tab adhesive tape winding and unwinding mechanism 1505 is started, the material collecting disc 15052 drives the tab adhesive tape 15055 to move to the welding area by adhering to the upper surface of the tab; the driving structure 1504 drives the upper electrode 1503 to descend, and the tab and the welding sheet are pressed 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 conduction path through the "upper electrode 1503-tab-welding sheet flow guide structure 2-lower electrode 1502", and the fusion welding of the tab and the welding sheet is realized by using the contact resistance to generate heat; during the welding process, the waterway assembly can also provide circulating cooling for the upper electrode 1503, the lower electrode 1502 and the transformer, the temperature sensing assembly 3 feeds back the temperature signal in real time, and if the temperature is abnormal, the control system automatically adjusts the current or stops.

[0081] After the welding is completed, the upper electrode 1503 is reset, the tab adhesive tape winding and unwinding mechanism 1505 recovers the used adhesive tape, the battery moving mechanism 140 drives the bearing plate 1405 to ascend and moves along the first guide rail 1401 to the discharging area, the clamp 1406 is loosened, and the discharging of the battery is completed; each mechanism is reset, and the next round of welding cycle is entered.

[0082] The foregoing is a summary and thus contains only the most basic embodiment. The application can be practiced with modification and alteration and still be within the scope of the application. This summary is not intended to mean that the application described herein will necessarily cover all of the subject matter shown, but it is stated in support of the claims as presented. The applications described herein will now be described with reference to the attached drawings. The drawings described herein are included to provide a description of the application and are not intended to limit the scope of the application. The same numbers are used in different drawings to represent the same or similar elements. The drawings are in simplified form and are not drawn to precise scale. In particular, the dimensions of the various components in the drawings are chosen so as to make the drawings clearer, not necessarily consistent with the dimensions of the various components actually employed. It should be understood that the application is not limited to the embodiments set forth herein, but can be practiced with modification and alteration, and still be within the scope and with the scope of the appended claims. Thus, it should be understood that although the use of the open-ended transitional phrases, such as, comprise, include, carry, have, contain, and the like, are used in the description and in the claims, these phrases are meant to be interpreted as non-limiting. The description and drawings are to be regarded as illustrative in nature and definitions in accordance with 35 U.S.C. § 112, as well as the six field of search limitations under 37 C.F.R. § 1.73 (effective September 8, 2001) are to be regarded. Any headings used herein are for organizational purposes only and are not meant to limit the scope of the application. Any examples of any element or component that can be found throughout this specification, including this summary and the following detailed description, are intended to be non-limiting unless expressly stated otherwise. Furthermore, the terms "comprise," "comprising," "include," "including," and the like are used herein to indicate the presence of stated elements or features, but not preclude the presence or addition of one or more other elements or features. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be apparent to those skilled in the art that various modifications and variations can be made to the present application without departing from the spirit or scope of the application. Thus, it is intended that the present application cover modifications and variations of this application provided they come within the scope of the appended claims and their equivalents.

[0083] For purposes of the USPTO extra-statutory invention, any incorporation by reference of the passage identified as "USPTO Extra-Statutory Invention Statement" is intended to render such passage a part of the specification. For purposes of the USPTO extra-statutory invention, the phrase "an extra-statutory invention of the [Inventor's Name]" anywhere in this specification or claims is intended to refer to the particular named invention. Moreover, for purposes of the USPTO extra-statutory invention, the phrase "at least one of the following", where that phrase is used in relation to a list of a number of identified conditions, is intended to mean one of or some combination of one or more of those conditions. Likewise, the phrase "at least one of the following", where that phrase is used in relation to a list of a number of identified structural elements, is intended to mean one or some combination of one or more of those elements.

[0084] In addition, it should be noted that the use of "first", "second", and the like words to define parts is merely for the convenience of distinguishing the corresponding parts, and the above words have no special meaning unless otherwise stated, and therefore cannot be understood as limiting the scope of protection of the present application. The above is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

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. 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; 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; 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; 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.

2. 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 claim 1. 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.

3. The welding apparatus according to claim 2, 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.

4. The welding apparatus according to claim 3, 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 tray and the take-up tray 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.

5. The welding apparatus according to claim 3, 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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