All-metal composite current collector and preparation method thereof
By forming a uniform metal layer on both sides of the substrate roll and performing a secondary evaporation of a mesh metal layer at the tab position to fill the height difference, the problem of warping during the winding of the composite current collector is solved, achieving optimization of conductivity and process efficiency, while reducing costs.
Patent Information
- Application Number
- CN202511042372.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-28
- Publication Date
- 2025-11-25
AI Technical Summary
During the fabrication of composite current collectors, the height difference between the pure metal tabs and the composite current collector causes the edges to curl up during winding, which causes problems for the client's operations.
A uniform metal layer is formed on both sides of the substrate roll, and an acid-resistant ink coating is printed on the first metal layer to form a mesh-like blank area. A second mesh-like metal layer is deposited on the side where the tab is located to fill the height difference. The ink is removed by alkaline washing to form a flat surface, which simplifies the process and reduces costs.
This invention solves the problem of edge warping during winding of composite current collectors, optimizes conductivity and process efficiency, reduces costs, and improves production efficiency and product quality.
Smart Images
Figure CN121006545A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of current collector material, in particular to a full-metal composite current collector and a preparation method thereof. BACKGROUND
[0002] Lithium ion batteries have been widely accepted in many fields such as consumer electronics, transportation, electric tools and energy storage. The current collector in the lithium ion battery, as one of the key components, plays a relatively important role. Its main role is to carry the electrode active material, collect and output the current generated by the active material, and input the electrode current to the active material.
[0003] At present, the composite current collector has many advantages such as reducing the weight of the battery, improving the energy density of the battery, improving the safety of the battery, and reducing the cost of the battery. However, the composite current collector has an additional tab welding process, and the process time and cost will increase accordingly. Therefore, a composite current collector with a pure metal tab can save subsequent cost and working hours. However, during the actual rolling process, the edge will be raised due to the height difference between the pure metal tab and the composite current collector, which will cause trouble to the customer's operation. SUMMARY
[0004] The present application aims to solve the problem that the edge of the composite current collector with a metal tab will be raised during the rolling process due to the height difference between the pure metal tab and the composite current collector in the prior art. The present application provides a full-metal composite current collector and a preparation method thereof, which systematically solves the edge warping problem of the composite current collector with a metal tab during rolling.
[0005] In order to achieve the above-mentioned purpose, the present application provides a preparation method of a full-metal composite current collector, comprising the following steps: S1, evaporating a first metal layer on the A surface of a base material roll; S2, forming an acid-resistant ink coating layer on the first metal layer, and forming a reticular blank area on the acid-resistant ink coating layer; S3, welding a metal tab on the side surface of the base material roll; S4, performing secondary metal evaporation on the reticular blank area of the acid-resistant ink coating layer to form a reticular metal layer, and removing the acid-resistant ink coating layer by alkaline washing; S5, cutting the formed roll material to obtain a full-metal composite current collector roll material.
[0006] As a further description of the above technical solution: in step S1, after evaporating the first metal layer on the A surface of the base material roll, a second metal layer is evaporated on the B surface of the base material roll.
[0007] As a further description of the above technical solution: in step S2, acid-resistant ink is printed on the first metal layer to form an acid-resistant ink coating layer.
[0008] As a further description of the above technical solution: in step S4, before the acid-resistant ink coating is removed by alkali washing, the B surface of the substrate roll is subjected to secondary metal evaporation to form a metal support layer, which covers the metal tab.
[0009] A full-metal composite current collector comprises a substrate layer, a first metal layer arranged on the upper surface of the substrate layer, a second metal layer arranged on the lower surface of the substrate layer, a metal tab welded on the side surface of the substrate layer, a mesh metal layer arranged on the upper surface of the first metal layer, and a metal support layer arranged on the lower surface of the second metal layer.
[0010] As a further description of the above technical solution: the first metal layer comprises a magnetron plating layer and a water plating layer, and the magnetron plating layer is arranged between the substrate layer and the water plating layer.
[0011] As a further description of the above technical solution: the second metal layer has the same structure as the first metal layer.
[0012] As a further description of the above technical solution: the upper surface of the metal tab is provided with a first connecting metal layer connected with the mesh metal layer.
[0013] As a further description of the above technical solution: the lower surface of the metal tab is provided with a second connecting metal layer connected with the metal support layer.
[0014] The above technical solution has the following advantages or beneficial effects:
[0015] The present application forms uniform metal layers on both surfaces of the substrate roll, ensures that the current collector has basic conductivity, prints the acid-resistant ink coating on the first metal layer, forms a mesh blank area on the acid-resistant ink coating, which is a blank area for subsequent secondary plating, and forms a flat surface by directly covering the metal tab and the first metal layer with the mesh metal layer on the surface where the metal tab is located, thereby solving the warping problem caused by edge stress concentration during winding. The exposed mesh metal layer naturally forms a conductive network when the ink is removed by alkali washing, thereby simplifying the process and reducing the cost. The edge warping problem of the composite current collector with a metal tab during winding is solved, and the conductivity, process efficiency and cost are optimized. BRIEF DESCRIPTION OF DRAWINGS
[0016] Figure 1 The present application is an embodiment of a full-metal tab composite current collector preparation method flowchart.
[0017] Figure 2 The present application is an embodiment of a full-metal tab composite current collector structure flowchart.
[0018] Figure 3A schematic diagram of slitting of the full-metal tab composite current collector coiled material in an embodiment of the present application;
[0019] Figure 4 A schematic diagram of the structure of the full-metal tab composite current collector in an embodiment of the present application.
[0020] Legend:
[0021] 1, base material roll; 101, base material layer; 2, first metal layer; 3, second metal layer; 4, acid-resistant ink coating layer; 5, metal tab; 6, mesh metal layer; 7, metal support layer; 8, first connecting metal layer; 9, first connecting metal layer; 201, magnetron plating layer; 202, water plating layer. DETAILED DESCRIPTION
[0022] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.
[0023] In the description of the present application, it should be noted that the orientations or positional relationships indicated by the terms "vertical", "upper", "lower", "horizontal" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.
[0024] Please refer to Figures 1-3 The present application provides a technical solution: a preparation method of a full-metal composite current collector, comprising the following steps: S1, evaporating a first metal layer 2 on the A surface of a base material roll 1, and evaporating a second metal layer 3 on the B surface of the base material roll 1; S2, forming an acid-resistant ink coating layer 4 on the first metal layer, and forming a mesh blank area on the acid-resistant ink coating layer 4; S3, welding a metal tab 5 on the side surface of the base material roll; S4, performing secondary metal evaporation on the mesh blank area of the acid-resistant ink coating layer to form a mesh metal layer 6, and removing the acid-resistant ink coating layer by alkaline washing; S5, slitting the formed coiled material to obtain a full-metal composite current collector coiled material.
[0025] In the technical scheme of the present application, by forming a uniform metal layer on both sides of the substrate roll 1, the current collector is ensured to have basic conductivity, by printing a covering acid-resistant ink coating 4 on the first metal layer 2, the net-shaped blank area formed on the acid-resistant ink coating 4 is a blank area reserved for subsequent secondary plating, and the metal tab is directly welded after plating, so that the composite current collector becomes a finished product with a metal tab, eliminating the welding process in the later stage of the battery factory, and by secondary evaporation of a net-shaped metal layer 6 on the surface where the metal tab 5 is located, the metal tab 5 and the first metal layer 2 are directly covered, filling the step between the metal tab 5 and the substrate roll 1, and forming a flat surface, which completely solves the problem of edge warping caused by stress concentration during winding, and the exposed net-shaped metal layer 6 naturally forms a conductive network during alkaline washing to remove ink, simplifying the process and reducing costs, and systematically solving the edge warping problem of the composite current collector with a metal tab during winding, while optimizing the conductivity, process efficiency and cost.
[0026] In the technical scheme of the present application, by forming a uniform metal layer on both sides of the substrate roll 1, the current collector is ensured to have basic conductivity, by printing a covering acid-resistant ink coating 4 on the first metal layer 2, the net-shaped blank area formed on the acid-resistant ink coating 4 is a blank area reserved for subsequent secondary plating, and the metal tab is directly welded after plating, so that the composite current collector becomes a finished product with a metal tab, eliminating the welding process in the later stage of the battery factory, and by secondary evaporation of a net-shaped metal layer 6 on the surface where the metal tab 5 is located, the metal tab 5 and the first metal layer 2 are directly covered, filling the step between the metal tab 5 and the substrate roll 1, and forming a flat surface, which completely solves the problem of edge warping caused by stress concentration during winding, and the exposed net-shaped metal layer 6 naturally forms a conductive network during alkaline washing to remove ink, simplifying the process and reducing costs, and systematically solving the edge warping problem of the composite current collector with a metal tab during winding, while optimizing the conductivity, process efficiency and cost.
[0027] Specifically, the substrate roll 1 can be selected from various non-polar or low-surface-energy high molecular materials, such as PP, PE, PS, PTFE, PMMA, PET, PA, PI, etc. The substrate roll 1 uses non-polar or low-surface-energy high molecular materials, which have good chemical stability and mechanical strength. This makes the composite current collector capable of exhibiting excellent performance in various application environments and compatible with different types of materials, meeting the needs of different fields. The first metal layer 2 is first printed with a specific shape of acid-resistant ink, and after curing, the net-shaped metal layer 6 is plated in the blank area to achieve support or other effects, and then the acid-resistant ink is removed by alkaline washing. The printed pattern is not limited.
[0028] As Figure 1 and Figure 2As shown, in step S4, before the acid-resistant ink coating layer 4 is removed by alkaline washing, the B surface of the substrate roll 1 is subjected to secondary metal evaporation to form a metal support layer 7, which covers the metal tab 5; through the metal support layer 7, not only the lower surface of the metal tab 5 is covered, but also the second metal layer 3 is combined, thereby providing structural support from both sides of the foil and further enhancing the overall flatness to ensure that the edges remain intact during winding.
[0029] In step S1, the first metal layer 2 and the second metal layer 3 are both copper layers, and the substrate roll 1 is fed into the roll evaporation coating machine, and the A surface of the substrate roll 1 is coated with a copper layer, and then the B surface of the substrate roll 1 is coated with a copper layer
[0030] The production process of the full-metal tab composite copper foil roll is as follows:
[0031] 1. Prepare a roll of 1350mm wide*4.5μm thick PET or other material substrate, feed it into the roll magnetron coating machine to coat the A / B surface with copper as the base to form a magnetron copper coating, each with a thickness of 80nm, running speed 20m / min, 14 copper targets on each side, total power controlled at 120kw, ion source cleaning voltage 700V;
[0032] 2. The copper-coated roll is fed into the water plating line, and the A / B surface is subjected to one-time water plating to quickly thicken the copper layer to form a water-plated copper layer, with the thickness of the A surface increasing to 1000nm and the thickness of the B surface increasing to 800nm, the unwinding tension being 90N, the winding tension being 80N, and the speed being 12m / min, the total current of the rectifier being 5500A;
[0033] 3. The water-plated roll is subjected to A-side roll-coated acid-resistant ink layer 4 with a printing thickness of 1-5μm, a line speed of 30m / min, a winding and unwinding tension of 100N, and a UV curing energy of 8000mJ / cm2;
[0034] The acid-resistant ink covers a specific area on the A surface, and during the subsequent secondary water plating, the copper layer in this area is protected from further thickening, ensuring that the non-ink area on the A surface has the same thickness as the tab, and the UV curing allows the ink to dry and cure quickly, forming a stable protective coating to prevent the ink from falling off during subsequent processes.
[0035] 4. Two rolls of 44mm wide*6.5μm pure copper foil tabs are subjected to roll-to-roll roll welding on a roll-to-roll rewinding machine, with a running speed of 100m / min, an unwinding tension of 100NN, and a winding tension that is automatically adjusted by the equipment, a welding width of 2mm, a welding down pressure of 0.4Mpa, and a vibration amplitude of 40%;
[0036] The roll-to-roll roll welding realizes continuous and rapid welding of the tab and the composite copper foil, which improves the production efficiency compared with the traditional welding method.
[0037] 5. Load the film with welded tabs onto the water plating line. Perform a second water plating on sides A and B. Thicken the non-ink area on side A. Increase the thickness of side B by 200nm on top of the 800nm thickness from the first water plating, for a total thickness of 1000nm. Increase the anode current in the tab area to make the overall thickness of side B uniform. After the copper plating is completed, perform alkaline washing to remove the acid-resistant ink. Soak in 5% sodium hydroxide solution for 1-3 minutes at 80℃. The unwinding tension is 80N, the winding tension is 70N, the speed is 10m / min, and the total current of the rectifier is 4500A.
[0038] Secondary water plating precisely adjusts the copper layer thickness by controlling the current and time, uses a leveling layer to eliminate the height difference between the tabs and the copper conductive layer, and removes the acid-resistant ink by alkaline washing to expose the copper layer, preparing for subsequent slitting, winding and battery assembly.
[0039] 6. Finally, feed the material into a precision slitting machine for slitting and winding. There are 5 slitting circular blades, each spaced 280mm apart. The slitting speed is 50m / min, the machine running speed is 80m / min, the unwinding tension is 100N, and the winding tension can be adjusted adaptively by the machine to obtain 4 rolls of all-metal tab composite copper foil.
[0040] Specifically, the precision slitting machine is equipped with five circular slitting blades. Through a five-blade slitting system, it can process four rolls of wide-width products in a single operation, ensuring cutting accuracy and efficiency even at high speeds. This configuration effectively improves production efficiency and reduces production cycles. Each slitting process yields four independent rolls of all-metal tab composite aluminum foil, increasing both output and efficiency. Furthermore, the size and quality of each roll remain consistent. The precision slitting machine's design allows it to handle materials of different specifications and thicknesses, making it highly adaptable. In different production batches, the blade spacing and slitting speed can be quickly adjusted according to requirements, ensuring that the cutting needs of various specifications of all-metal tab composite current collectors are met.
[0041] An all-metal composite current collector includes a substrate layer 101, a first metal layer 2 disposed on the upper surface of the substrate layer 101, a second metal layer 3 disposed on the lower surface of the substrate layer 101, metal tabs 5 welded to the side of the substrate layer 101, a mesh metal layer 6 disposed on the upper surface of the first metal layer 2, and a metal support layer 7 disposed on the lower surface of the second metal layer 3.
[0042] Specifically, the substrate layer 101 is lightweight and forms a composite structure with the first metal layer 2 and the second metal layer 3 on the upper and lower surfaces. While ensuring conductivity, it significantly reduces the overall weight of the current collector, meeting the requirements for lightweight batteries. A mesh metal layer 6 covers the surface of the first metal layer 2, and its mesh structure can "fill" the height difference between the metal tab 5 and the first metal layer, making the surface of the current collector flat. A metal support layer 7 is set on the lower surface of the second metal layer 3, forming upper and lower support with the mesh metal layer 6, further balancing the stress in the tab area, preventing the edges from curling up during winding, and improving the flatness and winding quality of the roll. The porous structure of the mesh metal layer 6 can buffer the volume expansion stress during battery charging and discharging, reducing the risk of metal layer cracking. The metal support layer 7 is combined with the second metal layer 3 to enhance the overall mechanical strength of the current collector and reduce the probability of breakage during transportation and processing.
[0043] like Figure 4 As shown, the first metal layer 2 includes a magnetron sputtering layer 201 and a water-plated layer 202. The magnetron sputtering layer 201 is disposed between the substrate layer 101 and the water-plated layer 202. The magnetron sputtering layer 201 forms a uniform and dense metal film on the surface of the substrate layer 101 through a magnetron sputtering process, providing an initial conductive basis. The water-plated layer 202 further thickens the metal layer through electroplating, enhances conductivity, and meets the current transmission requirements in battery use.
[0044] The second metal layer 3 has the same structure as the first metal layer 2.
[0045] like Figure 4 As shown, the upper surface of the metal tab 5 is provided with a first connecting metal layer 8 connected to the mesh metal layer 6, and the lower surface of the metal tab 5 is provided with a second connecting metal layer 9 connected to the metal support layer 7. The first connecting metal layer 8 on the upper surface of the tab is connected to the mesh metal layer 6, and the second connecting metal layer 9 on the lower surface is connected to the metal support layer 7, forming a conductive network that runs through the entire structure. This ensures the uniformity of conductivity between the tab and the current collector, reduces contact resistance, and the connecting metal layer is integrally formed with the tab and the mesh metal layer through vapor deposition or electroplating processes. This process has strong compatibility and avoids contact failure problems caused by poor welding.
[0046] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.
[0047] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.
Claims
1. A method for preparing an all-metal composite current collector, characterized in that, Includes the following steps: S1. A first metal layer is vapor-deposited on side A of the substrate roll; S2. An acid-resistant ink coating is formed on the first metal layer, and a mesh-like blank area is formed on the acid-resistant ink coating; S3. Weld metal tabs to the side of the substrate roll; S4. Perform secondary metal vapor deposition on the mesh-like blank area of the acid-resistant ink coating to form a mesh-like metal layer, and then remove the acid-resistant ink coating by alkaline washing. S5. Cut the formed roll material to obtain an all-metal composite current collector roll material.
2. The method for preparing the all-metal composite current collector according to claim 1, characterized in that: In step S1, after the first metal layer is deposited on side A of the substrate roll, the second metal layer is deposited on side B of the substrate roll.
3. The method for preparing the all-metal composite current collector according to claim 1, characterized in that: In step S2, acid-resistant ink is printed on the first metal layer to form an acid-resistant ink coating.
4. The method for preparing the all-metal composite current collector according to claim 2, characterized in that: In step S4, before the acid-resistant ink coating is removed by alkaline washing, the B side of the substrate roll is first subjected to secondary metal vapor deposition to form a metal support layer, which also covers the metal tabs.
5. An all-metal composite current collector, characterized in that: It includes a substrate layer, a first metal layer disposed on the upper surface of the substrate layer, a second metal layer disposed on the lower surface of the substrate layer, metal tabs welded to the side of the substrate layer, a mesh metal layer disposed on the upper surface of the first metal layer, and a metal support layer disposed on the lower surface of the second metal layer.
6. The all-metal composite current collector according to claim 5, characterized in that: The all-metal composite current collector is prepared by the preparation method described in any one of claims 1-4.
7. The all-metal composite current collector according to claim 5, characterized in that: The first metal layer includes a magnetron plating layer and a water plating layer, wherein the magnetron plating layer is disposed between the substrate layer and the water plating layer.
8. The all-metal composite current collector according to claim 5, characterized in that: The second metal layer has the same structure as the first metal layer.
9. The all-metal composite current collector according to claim 5, characterized in that: The upper surface of the metal tab is provided with a first connecting metal layer that is connected to the mesh metal layer.
10. The all-metal composite current collector according to claim 5, characterized in that: The lower surface of the metal tab is provided with a second connecting metal layer that is connected to the metal support layer.