A welding head structure and a composite current collector transfer welding system
By designing welding head structures with different shapes and anti-stick coatings, the problem of uneven stress in composite current collector transfer welding was solved, achieving high-quality welding and industrialized production, and improving welding strength and production efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- YANGZHOU NANOPORE INNOVATIVE MATERIALS TECH LTD
- Filing Date
- 2025-06-03
- Publication Date
- 2026-06-09
Smart Images
Figure CN224333749U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of new energy material processing technology, and in particular to a welding head structure and a composite current collector transfer welding system. Background Technology
[0002] With the global energy structure transformation and the rapid development of the electric vehicle industry, lithium-ion batteries, as core energy storage devices, have become a key focus of industry attention in terms of energy density, safety, and cost. Traditional lithium-ion batteries use pure metal (copper or aluminum foil) as current collectors. Although they have good conductivity, under high energy density, fast charging, and extreme operating conditions, metal current collectors are susceptible to risks such as lithium dendrite puncture and thermal runaway, which restricts further improvements in battery performance.
[0003] To address the shortcomings of traditional current collectors, composite current collectors have emerged. Composite current collectors form a "metal-insulator-metal" composite structure by depositing ultra-thin metal layers on both sides of a polymer substrate (such as PET or PP), combining the conductivity of metals with the lightweight, flexibility, and thermal stability of polymer materials. Compared to traditional metal foils, composite current collectors can significantly reduce battery weight, increase energy density, and effectively suppress lithium dendrite penetration, enhancing battery safety. Furthermore, reducing the amount of copper / aluminum used makes composite current collectors more cost-effective than pure metal current collectors.
[0004] However, the middle layer of the composite current collector is a non-conductive polymer layer, requiring a transition soldering process to achieve conductivity. Transition soldering involves welding a layer of conventional metal foil to each of the metal layers on both sides of the composite current collector. The protruding ends of these conventional metal foils are then welded together to conduct the current, and conductivity is achieved through pre-welding. Currently, when performing transition soldering on composite current collectors, a wide foil is typically welded to one side and a narrow foil to the other. The protruding end of the narrow foil is only required to weld to the wide foil, thus achieving conductivity of the composite current collector with only one foil layer extending out.
[0005] During the transfer welding of composite current collectors, the composite current collector and transfer foil are stacked according to the requirements of the transfer welding, forming a three-layer zone on one side (transfer foil + composite current collector + transfer foil) and a two-layer zone on the other side (transfer foil + transfer foil). This welding method is prone to uneven stress on the three-layer side and the two-layer side during welding, which can cause the material strips to shift and affect the welding yield. Utility Model Content
[0006] In view of the problem of uneven stress distribution between three-layer and two-layer side welding materials in the above or existing technologies, this utility model is proposed.
[0007] Therefore, the purpose of this utility model is to provide a welding head structure.
[0008] To solve the above-mentioned technical problems, this utility model provides the following technical solution: a welding seat, wherein the working surface of the welding seat includes a first welding tooth surface and a second welding tooth surface;
[0009] The first welding tooth is disposed on the surface of the first welding tooth;
[0010] The second welding tooth is disposed on the surface of the second welding tooth; and the first welding tooth and the second welding tooth have different shapes.
[0011] As a preferred embodiment of the welding head structure of this utility model, the width of the first welding tooth surface is set to L1, the width of the second welding tooth surface is set to L2, and during welding, the first welding tooth surface corresponds to the double-layer area, and the second welding tooth surface corresponds to the triple-layer area.
[0012] In a preferred embodiment of the welding head structure of this utility model, the width L1 of the first welding tooth surface is smaller than the width L2 of the second welding tooth surface; wherein L1 is set to 2±0.1mm and L2 is set to 2.5±0.1mm.
[0013] As a preferred embodiment of the welding head structure of this utility model, the top surface of the first welding tooth is provided as a planar structure, and the vertical distance h1 from the top surface of the first welding tooth to the surface where the bottom of the first welding tooth is located is set to 0.09±0.01mm.
[0014] In a preferred embodiment of the welding head structure of this utility model, the second welding tooth is provided with a ball-shaped structure, the diameter r2 of the second welding tooth is set to 0.7±0.05mm, and the height h2 of the second welding tooth is set to 0.08±0.01mm.
[0015] As a preferred embodiment of the welding head structure of this utility model, it further includes a third welding tooth, wherein a plurality of third welding teeth are provided, the plurality of third welding teeth are arranged in a longitudinal row and are disposed between the first welding tooth and the second welding tooth.
[0016] In a preferred embodiment of the welding head structure of this utility model, the third welding tooth is cylindrical, and the top surface of the cylindrical third welding tooth is spherical.
[0017] As a preferred embodiment of the welding head structure of this utility model, the transverse spacing between the first welding teeth, the transverse spacing between the second welding teeth, and the transverse spacing between the first welding teeth and the second welding teeth are set to m, where m is 0.2±0.05mm; the longitudinal spacing between the first welding teeth and the longitudinal spacing between the second welding teeth are set to n, where n is 0.3±0.05mm.
[0018] As a preferred embodiment of the welding head structure of this utility model, at least one of the four components—the welding seat, the first welding tooth, the second welding tooth, and the third welding tooth—has an anti-stick coating on its surface.
[0019] In a preferred embodiment of the welding head structure of this utility model, the anti-stick coating is a ceramic material layer.
[0020] The beneficial effects of the welding head structure of this utility model are as follows: By setting the first welding tooth and the second welding tooth, this utility model effectively avoids the phenomenon of weld penetration and adhesion in the double-layer area during transition welding, as well as the phenomenon of foil material deviation, thereby improving the welding strength of the three-layer area and avoiding false welding; and ensuring that the foil materials in the three-layer area and the double-layer area remain in a tight state when the welding seat is pressed down.
[0021] In practical use, there is still the problem that the current collector is not convenient for industrial mass production.
[0022] To solve the above-mentioned technical problems, the present invention also provides the following technical solution: a composite current collector transfer welding system, including an unwinding shaft assembly, wherein the unwinding shaft is used to unwind the material to be welded;
[0023] Tension swing arm, which is used to convey the material to be welded and the composite current collector after transfer welding;
[0024] The feeding cylinder can press the material to be welded conveyed by the tension swing arm;
[0025] A welding mechanism, comprising the aforementioned welding head structure, wherein the welding mechanism welds the compressed materials together as a single unit;
[0026] A cleaning device is provided on the welding mechanism for cleaning the aforementioned welding head structure;
[0027] The online CCD inspection device is used to inspect the composite current collector after the transition welding.
[0028] A winding mechanism is used to collect the weld transfer welding composite current collector after welding inspection into a roll.
[0029] The beneficial effects of this utility model's composite current collector transfer welding system are: it realizes the industrial mass production of composite current collector transfer welding, and improves the production efficiency and finished product yield of composite current collector transfer welding. Attached Figure Description
[0030] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0031] Figure 1 This is a top view of the welded joint structure.
[0032] Figure 2 This is a cross-sectional view of the welded joint structure.
[0033] Figure 3 This is a schematic diagram of the overall composite current collector transfer welding system.
[0034] Figure 4 This is a schematic diagram of the composite current collector transfer welding layer structure.
[0035] Figure 5 This is a schematic diagram of the strength test method for composite current collectors after welding.
[0036] Figure 6 This is a schematic diagram of the overcurrent resistance test method after the composite current collector is transferred and welded. Detailed Implementation
[0037] To enable those skilled in the art to better understand this utility model, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings.
[0038] The terminology used in this invention refers to those general terms currently widely used in the art in consideration of the functionality of this invention; however, these terms may vary according to the intent, precedent, or new technology of those skilled in the art. Furthermore, specific terms may be chosen by the applicant, and in such cases, their detailed meanings will be described in the detailed description of this invention. Therefore, the terminology used in this specification should not be construed as simple names, but rather based on the meaning of the terms and the overall description of this invention.
[0039] Reference Figure 1 This embodiment provides a welding head structure, including a welding seat 100. The working surface of the welding seat 100 is machined with welding teeth, which are in contact with the material to be welded. The other side of the welding seat 100 is connected to an ultrasonic generator for transmitting ultrasonic waves to the material to be welded through the welding teeth.
[0040] As an optional embodiment, refer to Figure 1 The working surface of the welding seat 100 includes a first welding tooth surface 101, on which a first welding tooth 200 is machined, and a second welding tooth surface 102, on which a second welding tooth 300 is machined.
[0041] The welding head structure of this utility model is mainly used for welding composite current collectors and transfer foils. When the composite current collector and the foil are transferred, the composite current collector and the transfer foil are stacked according to the needs of the transfer welding, forming a three-layer area on one side, namely transfer foil + composite current collector + transfer foil, and a two-layer area on the other side, namely transfer foil + transfer foil.
[0042] In order to meet the requirement that the three-layer area on one side and the two-layer area on the other side need to be welded simultaneously during the current collector transfer welding, the first welding tooth 200 and the second welding tooth 300 are set with different shapes. In this embodiment, the top surface of the first welding tooth 200 is set with a planar structure; the second welding tooth 300 is processed into a ball head structure.
[0043] Because the ball-head structure weld teeth mesh more tightly with the base and can form a more uniform and firm joint during welding, but the pressure is concentrated at the ball head, it is easy to weld through. Therefore, the ball-head structure weld teeth are used in the three-layer area with a thicker welding thickness to ensure the welding strength of the three-layer area and avoid incomplete welding.
[0044] Because the top surface of the welding teeth is planar, it can provide a larger contact area, disperse the heat and pressure during welding, reduce local overheating and stress concentration, and thus reduce the risk of burn-through and adhesion. Therefore, when welding double-layer areas, truncated pyramidal welding teeth are used to avoid burn-through and adhesion.
[0045] As an optional embodiment, refer to Figure 1 The width of the first welding tooth surface 101 is set to L1, and the width of the second welding tooth surface 102 is set to L2.
[0046] Specifically, the width L1 of the first welding tooth surface 101 is smaller than the width L2 of the second welding tooth surface 102.
[0047] When performing transition welding on the composite current collector, the total width of the welding teeth on the welding seat 100 is typically set to 4.5±0.1mm. Specifically, the first welding tooth 200 on the first welding tooth surface 101 corresponds to the double-layer area for welding, and the width L1 of the first welding tooth surface 101 is set to 2±0.1mm; the second welding tooth 300 on the second welding tooth surface 102 corresponds to the triple-layer area for welding, and the width L2 of the second welding tooth surface 102 is set to 2.5±0.1mm. For ease of understanding, in Figure 2 The first welding tooth surface 101 and the second welding tooth surface 102 are separated by a dotted line. The left side is the first welding tooth surface 101, which corresponds to the double-layer area; the right side is the second welding tooth surface 102, which corresponds to the triple-layer area.
[0048] As an optional embodiment, the first welding tooth 200 is preferably a frustum structure. Further, the frustum structure can be a square frustum, a pentagonal frustum, a hexagonal frustum, etc. In this embodiment, it is set as a square frustum, referring to... Figure 2 .
[0049] When the first welding tooth 200 is set in the form of a quadrangular frustum, the height of the first welding tooth 200 is set to h1, the top side length of the first welding tooth is set to a, and the bottom side length of the first welding tooth is set to b.
[0050] Specifically, the height of the first weld tooth, i.e., the vertical distance h1 from the top surface of the first weld tooth 200 to the plane containing the bottom of the first weld tooth 200, is set to 0.09±0.01mm, the top edge length a of the first weld tooth is set to 0.6±0.05mm, and the bottom edge length b of the first weld tooth is set to 0.8±0.05mm.
[0051] As an optional embodiment, refer to Figure 2 The second welding tooth 300 is set in a ball head structure, the diameter of the second welding tooth is set to r2, and the height of the second welding tooth is set to h2.
[0052] Specifically, the diameter r2 of the second welding tooth is set to 0.7±0.05mm, and the height h2 of the second welding tooth is set to 0.08±0.01mm.
[0053] The value of h2 is less than that of h1 because, firstly, during the transition welding process, the overall thickness of the foil in the double-layer area is thinner, and the foil may shift due to uneven force during the foil conveyor belt process. Therefore, the height h1 of the first welding tooth is set to 0.09±0.01mm, and the higher tooth pattern helps to fix the foil in the double-layer area. Secondly, the total thickness of the triple-layer area is increased relative to the double-layer area, and it is also necessary to ensure welding strength and avoid incomplete welding. Therefore, the height h2 of the second welding tooth is set to 0.08±0.01mm. The above dimensional settings ensure that the foil in the triple-layer area and the double-layer area remain in close contact when the welding seat 100 is pressed down, thus improving the welding quality.
[0054] As an optional embodiment, refer to Figure 1 The lateral spacing between the first welding teeth 200, the lateral spacing between the second welding teeth 300, and the lateral spacing between the first welding teeth 200 and the second welding teeth 300 are all set to m, and the value of m is preferably 0.2±0.05mm.
[0055] Reference Figure 1 The longitudinal spacing between the first welding teeth 200 and the longitudinal spacing between the second welding teeth 300 are both set to n, and the value of n is preferably 0.3±0.05mm.
[0056] Preferably, the welded joint structure further includes a third welding tooth 500 to avoid the problem of poor flatness between the double-layer and triple-layer areas after the first welding tooth 200 welds the double-layer area and the second welding tooth 300 welds the triple-layer area. Several third welding teeth 500 are provided, arranged in a longitudinal row between the first welding teeth 200 and the second welding teeth 300; specifically, the third welding teeth 500 are machined at the intersection of the lines connecting two adjacent first welding teeth 200 and two second welding teeth 300, as shown in the reference. Figure 1 .
[0057] Furthermore, the third welding tooth 500 is cylindrical, and the top surface of the third welding tooth 500 is spherical. The diameter of the third welding tooth r3 is less than or equal to 0.5m; the value of h1 is greater than or equal to the height of the third welding tooth h3, which is greater than or equal to the value of h2.
[0058] Furthermore, at least one of the surfaces of the welding seat 100, the first welding tooth 200, the second welding tooth 300, and the third welding tooth 500 is provided with an anti-stick coating; preferably, all four surfaces of the welding seat 100, the first welding tooth 200, the second welding tooth 300, and the third welding tooth 500 are provided with an anti-stick coating, which is a ceramic material layer.
[0059] Specifically, ceramic materials are infiltrated and adhered to the surface of the weld joint structure using chemical vapor deposition to form an anti-stick coating, reducing the amount of metal shavings generated during welding that stick to the welding seat and welding teeth, thus affecting subsequent use.
[0060] This utility model also discloses a composite current collector transfer welding system 400, as shown in the reference. Figure 3 It includes an unwinding shaft assembly, which is used to unwind the material to be welded; the unwinding shaft assembly includes a narrow foil unwinding shaft 403, an electrode unwinding shaft 401 and a wide foil unwinding shaft 402, which are spaced apart in a top, middle and bottom manner.
[0061] Tension swing arm 404 is used to convey the material to be welded and guide the composite current collector after the transfer welding. There are four sets of tension swing arms 404, three of which are respectively adjacent to the narrow foil unwinding shaft 403, the electrode unwinding shaft 401 and the wide foil unwinding shaft 402, and are used to guide the material to be welded released from the narrow foil unwinding shaft 403, the electrode unwinding shaft 401 and the wide foil unwinding shaft 402.
[0062] The feeding cylinder 405 is located adjacent to the three sets of tension swing rods 404 and is situated on the discharge side of the three sets of tension swing rods 404, so as to fit the material to be welded conveyed by the tension swing rods 404.
[0063] Welding mechanism 406 is located near the feed cylinder 405 and on the discharge side of the feed cylinder 405. Welding mechanism 406 includes the aforementioned welding head structure. Welding mechanism 406 welds the bonded materials together to form a transfer welding composite current collector through the welding head structure.
[0064] A cleaning device 407 is installed on the welding mechanism 406 and is used to clean the welding head structure. The cleaning device includes two parts: blowing and cleaning. The blowing part uses an air nozzle to blow the welding head structure and welding materials to remove metal dust generated during welding. The cleaning part uses a felt to continuously wipe the welding head structure. The felt contains alcohol, which can be continuously supplied by dripping.
[0065] The CCD online inspection device 408 is located near the welding mechanism 406 and on the discharge side of the welding mechanism 406. The CCD online inspection device 408 is used to detect whether there are defects such as welding perforation in the transfer welding composite current collector.
[0066] The detection side of the CCD online inspection device 408 is also equipped with a fourth set of tension swing rods 404, which are used to sort the composite current collector after the transfer welding inspection.
[0067] The winding mechanism 409 is located near the fourth set of tension swing rods 404 and on the discharge side of the fourth set of tension swing rods 404. The winding mechanism 409 is used to collect the composite current collector after the transfer welding into a roll.
[0068] After adopting the above-mentioned welding head structure, the tensile test value of the composite current collector sample after the transfer welding was improved. The tensile test results are shown in Table 1.
[0069] Table 1 shows the tensile strength values of the frustum weld teeth, the ball head weld teeth, and the sample of this embodiment. Five groups of samples of each type of weld tooth were tested and the average value was taken. It can be seen that the tensile strength value of the sample welded with the weld head structure of this embodiment is significantly higher than that of the sample welded with the frustum weld teeth, while taking into account the special characteristics of welding in the double-layer and triple-layer areas.
[0070] Table 1
[0071] Tension / N 1 2 3 4 5 mean Four-sided frustum welding teeth 32 35 40 33 34 34.8 Ball head welding teeth 44 45 42 43 42 43.2 This embodiment 36 40 40 42 37 39
[0072] The tensile testing method adopts the weld strength test, referencing... Figure 5The composite current collector after the transition weld is clamped onto a dedicated welding strength tester. The clamping method involves clamping the lower end of foil G on one side and the upper end of foil H on the other side, while simultaneously applying opposing forces F to the clamping ends. For example, clamping the upper end of foil H will result in an upward pulling force F, and clamping the lower end of foil G will result in a downward pulling force F. The pulling force that separates the foil from the composite current collector is recorded.
[0073] The welded samples were placed under a film viewing lamp for observation at several points. The weld perforation rate was reduced by 50% compared to welding with only ball-head weld teeth. Due to the reduction in weld perforation rate, the resistance test value could also be maintained in a lower range. The resistance test values are shown in Table 2, which shows the tensile values of ball-head weld teeth, frustum weld teeth, and this embodiment. Five groups of samples of each type of weld tooth were tested and the average value was taken. It can be seen that the resistance value of the sample welded with the welding head structure of this embodiment is close to the resistance value of the sample welded with frustum weld teeth, which is better than the resistance value of the sample welded with only ball-head weld teeth.
[0074] Table 2
[0075] Resistance / mΩ 1 2 3 4 5 mean Ball head welding teeth 0.35 0.40 0.39 0.38 0.41 0.386 Four-sided frustum welding teeth 0.23 0.25 0.25 0.23 0.24 0.24 This embodiment 0.28 0.24 0.29 0.27 0.23 0.256
[0076] The test method uses overcurrent resistance testing, with test points P1 and P2 selected. P1 and P2 are located on either side of the solder joints between foil H and foil G and the composite current collector J, respectively. (Refer to...) Figure 6 .
[0077] When using this invention for composite current collector transfer welding, a schematic diagram of the composite current collector and transfer foil stacking is shown below. Figure 4 As shown, in order to reduce the amount of foil used, the foil on both sides of the composite current collector is set with unequal widths, with the wide foil width set to 20-40mm and the narrow foil width set to 6-10mm.
[0078] Figure 4 In the diagram, A represents narrow foil, B represents tab blanking, C represents wide foil, D represents a three-layer area, and E represents a two-layer area.
[0079] Finally, it should be noted that the aforementioned unwinding shaft, tension swing arm, cylinder, welding mechanism, cleaning device, CCD online inspection device, and winding mechanism are all existing structures and will not be described in detail here. The methods and equipment described in detail above are merely embodiments, and those skilled in the art can modify these embodiments in different ways, as long as they do not depart from the scope of this utility model.
Claims
1. A welding head structure, characterized in that: include, The welding seat (100) has a working surface including a first welding tooth surface (101) and a second welding tooth surface (102). The first welding tooth (200) is disposed on the first welding tooth surface (101); The second welding tooth (300) is disposed on the second welding tooth surface (102); and the first welding tooth (200) and the second welding tooth (300) have different shapes.
2. The welding head structure as described in claim 1, characterized in that: The width of the first welding tooth surface (101) is set to L1, and the width of the second welding tooth surface (102) is set to L2. The width L1 of the first welding tooth surface (101) and the width L2 of the second welding tooth surface (102) are not equal.
3. The welding joint structure as described in claim 1 or 2, characterized in that: The width of the first welding tooth surface (101) is set to L1, and the width of the second welding tooth surface (102) is set to L2. During welding, the first welding tooth surface (101) corresponds to the double-layer area, and the second welding tooth surface (102) corresponds to the triple-layer area. The width L1 of the first welding tooth surface (101) is smaller than the width L2 of the second welding tooth surface (102).
4. The welding joint structure as described in claim 1 or 2, characterized in that: The top surface of the first welding tooth (200) is set in a planar structure, and the vertical distance h1 from the top surface of the first welding tooth (200) to the bottom surface of the first welding tooth (200) is set to 0.09±0.01mm.
5. The welding joint structure as described in claim 1 or 2, characterized in that: The second welding tooth (300) is configured with a ball head structure, the diameter r2 of the second welding tooth (300) is set to 0.7±0.05mm, and the height h2 of the second welding tooth is set to 0.08±0.01mm.
6. The welding joint structure as described in claim 1 or 2, characterized in that: It also includes a third welding tooth (500), of which a plurality of third welding teeth (500) are provided, and the plurality of third welding teeth (500) are arranged in a longitudinal row and disposed between the first welding tooth (200) and the second welding tooth (300).
7. The welding joint structure as described in claim 6, characterized in that: The third welding tooth (500) is cylindrical, and the top surface of the cylinder of the third welding tooth (500) is spherical.
8. The welding joint structure as described in any one of claims 1, 2, and 7, characterized in that: The lateral spacing between the first welding teeth (200), the lateral spacing between the second welding teeth (300), and the lateral spacing between the first welding teeth (200) and the second welding teeth (300) are set to m, where m is 0.2 ± 0.05 mm; the longitudinal spacing between the first welding teeth (200) and the longitudinal spacing between the second welding teeth (300) are set to n, where n is 0.3 ± 0.05 mm.
9. The welding head structure as described in claim 7, characterized in that: Of the four welding seats (100), the first welding tooth (200), the second welding tooth (300), and the third welding tooth (500), at least one surface is provided with an anti-stick coating.
10. A composite current collector transfer welding system, characterized in that: include, An unwinding shaft assembly, wherein the unwinding shaft is used to unwind the material to be welded; Tension swing arm (404), the tension swing arm (404) is used to convey the material to be welded and the composite current collector after transfer welding; Feed cylinder (405), which can fit the material to be welded conveyed by the tension swing rod (404); Welding mechanism (406), the welding mechanism (406) includes the welding head structure as described in claim 1, the welding mechanism (406) welds the compressed materials together; A cleaning device (407) is provided on the welding mechanism (406) for cleaning the aforementioned welding head structure; CCD online inspection device (408), the CCD online inspection device (408) is used to inspect the composite current collector after the transition welding; A winding mechanism (409) is used to collect the tested transfer welding composite current collector into a roll.