Full-metal tab composite copper foil convenient to wind

Abstract

The utility model relates to lithium battery material technical field especially, more particularly to a full metal tab composite copper foil convenient to wind, this full metal tab composite copper foil convenient to wind includes base material layer, the first copper conductive layer is provided with on base material layer upper surface, the second copper conductive layer is provided with on base material layer lower surface, the tab is welded with in base material layer side, the first filling layer is provided with on first copper conductive layer upper surface, the second filling layer is provided with on tab lower surface. Through filling layer cover on first copper conductive layer and tab upper surface, the second filling layer covers on tab lower surface and second copper conductive layer lower surface, the filling layer formed through water plating copper process, fills up the height difference between tab and copper conductive layer, makes composite copper foil surface even, avoids tab and copper foil edge in the winding process and rises, promotes winding quality and appearance, and the filling layer is closely combined with tab and copper conductive layer, not only eliminates height difference, further strengthens the connecting strength between tab and composite copper foil.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery material technology, and in particular to an all-metal tab composite copper foil that is easy to roll up. Background Technology

[0002] In the field of lithium battery technology, current collectors are a key component of battery structure, and their performance directly affects the overall performance of lithium batteries. Composite copper foil, as a new generation of negative electrode current collectors, has attracted much attention due to its unique structural and performance advantages.

[0003] In practical applications, composite copper foil requires an additional tab welding process compared to traditional pure copper foil. This not only extends the production cycle but also increases process costs, hindering large-scale industrial production and cost control. To address these issues, the industry has developed composite copper foil with integrated pure metal tabs. By pre-integrating the tabs onto the composite copper foil, the subsequent tab welding process is reduced, saving costs and time to some extent. However, this solution still has drawbacks in actual production and application. Due to the height difference between the pure metal tabs and the composite copper foil, the edges of the tabs and the composite copper foil are prone to warping during actual winding. This not only affects the winding quality and appearance of the composite copper foil but also causes problems such as installation difficulties and impacts on battery assembly accuracy and reliability during customer operations, limiting the widespread application of composite copper foil with integrated pure metal tabs. Utility Model Content

[0004] The purpose of this invention is to solve the problem that in the existing technology of traditional composite copper foil, due to the height difference between the pure metal tabs and the composite copper foil, the edges of the tabs and the composite copper foil are prone to curling up during the actual winding process. This invention provides a composite copper foil with all-metal tabs that is easy to wind up, which can fill the height difference between the tabs and the copper conductive layer, making the surface of the composite copper foil flat and preventing the edges of the tabs and the copper foil from curling up during the winding process.

[0005] To achieve the above objectives, this utility model provides an all-metal tab composite copper foil that is easy to wind up, comprising a substrate layer, a first copper conductive layer disposed on the upper surface of the substrate layer, a second copper conductive layer disposed on the lower surface of the substrate layer, tabs welded to the side of the substrate layer, a first leveling layer disposed on the upper surface of the first copper conductive layer, and a second leveling layer disposed on the lower surface of the tabs.

[0006] As a further description of the above technical solution: the first copper conductive layer includes a magnetron copper plating layer and a first water-plated copper layer, wherein the magnetron copper plating layer is disposed between the substrate layer and the first water-plated copper layer.

[0007] As a further description of the above technical solution: the first leveling layer includes a grid copper support layer, the grid copper support layer is disposed on the upper surface of the first copper conductive layer, and a second water-plated copper layer is disposed on one side of the grid copper support layer, the second water-plated copper layer is disposed on the upper surface of the tab.

[0008] As a further description of the above technical solution: the second leveling layer includes a water-plated copper support layer, the water-plated copper support layer is disposed on the lower surface of the electrode tab, and a third water-plated copper layer is disposed on one side of the water-plated copper support layer, the third water-plated copper layer is disposed on the lower surface of the second copper conductive layer.

[0009] As a further description of the above technical solution: the thickness of the substrate layer is 2.5 to 8 μm.

[0010] As a further description of the above technical solution: the thickness of both the first copper conductive layer and the second copper conductive layer is 300-1000 nm.

[0011] As a further description of the above technical solution: the second copper conductive layer has the same structure as the first copper conductive layer.

[0012] As a further description of the above technical solution: the upper surface of the grid copper support layer and the upper surface of the second water-plated copper layer are on the same horizontal plane.

[0013] As a further description of the above technical solution: the lower surface of the water-plated copper support layer and the lower surface of the third water-plated copper layer are on the same horizontal plane.

[0014] The above technical solution has the following advantages or beneficial effects:

[0015] This invention uses a leveling layer covering the first copper conductive layer and the upper surface of the tab, and a second leveling layer covering the lower surface of the tab and the lower surface of the second copper conductive layer. The leveling layer, formed by a water-plating copper process, fills the height difference between the tab and the copper conductive layer, making the surface of the composite copper foil flat. This prevents the edges of the tab and the copper foil from lifting during the winding process, improving the winding quality and appearance. The leveling layer is tightly bonded to the tab and the copper conductive layer, not only eliminating the height difference but also further enhancing the connection strength between the tab and the composite copper foil, preventing the tab from falling off during use. The flat surface facilitates subsequent battery assembly, reduces installation difficulty, and improves battery assembly accuracy and reliability. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the composite copper foil structure in one embodiment of the present invention;

[0017] Figure 2 for Figure 1 Schematic diagram of the structure of the medium-grid copper support layer;

[0018] Figure 3This is a schematic diagram of the welding between the substrate layer and the tab 4 in one embodiment of the present invention.

[0019] Legend:

[0020] 1. Substrate layer; 2. First copper conductive layer; 3. Second copper conductive layer; 4. Tab; 5. First leveling layer; 6. Second leveling layer; 7. Acid-resistant ink layer; 201. Magnetron copper plating layer; 202. First water-plated copper layer; 51. Mesh copper support layer; 52. Second water-plated copper layer; 61. Water-plated copper support layer; 62. Third water-plated copper layer. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] In the description of this utility model, it should be noted that the terms "vertical", "up", "down", "horizontal", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0023] like Figure 1-3 As shown, the present invention provides an easy-to-wind all-metal tab composite copper foil, comprising a substrate layer 1, a first copper conductive layer 2 disposed on the upper surface of the substrate layer 1, a second copper conductive layer 3 disposed on the lower surface of the substrate layer 1, tabs 4 welded to the side of the substrate layer 1, a first leveling layer 5 disposed on the upper surface of the first copper conductive layer 2, and a second leveling layer 6 disposed on the lower surface of the tabs 4.

[0024] In the technical solution of this utility model, a leveling layer 5 covers the upper surface of the first copper conductive layer 2 and the tab 4, and is composed of a grid copper support layer 51 and a second water-plated copper layer 52. A second leveling layer 6 covers the lower surface of the tab 4 and the lower surface of the second copper conductive layer 3, and is composed of a water-plated copper support layer 61 and a third water-plated copper layer 62. The leveling layer formed by the water-plating copper process fills the height difference between the tab 4 and the copper conductive layer, making the surface of the composite copper foil flat, avoiding the tab and copper foil edges from lifting during the winding process, improving the winding quality and appearance. The leveling layer is tightly bonded to the tab and the copper conductive layer, not only eliminating the height difference, but also further enhancing the connection strength between the tab and the composite copper foil, preventing the tab from falling off during use. The flat surface is beneficial for subsequent battery assembly, reducing installation difficulty, improving battery assembly accuracy and reliability, and reducing problems such as poor contact caused by uneven surfaces.

[0025] like Figure 1 and Figure 2 As shown, the first copper conductive layer 2 includes a magnetron sputtering copper layer 201 and a first water-plated copper layer 202. The magnetron sputtering copper layer 201 is disposed between the substrate layer 1 and the first water-plated copper layer 202. The magnetron sputtering copper layer 201 forms a uniform and dense copper film on the surface of the substrate through a magnetron sputtering process, providing an initial conductive foundation. The first water-plated copper layer 202 further thickens the copper layer through electroplating, enhancing conductivity and meeting the current transmission requirements during battery use.

[0026] The substrate layer 1 has a thickness of 2.5–8 μm, and the first copper conductive layer 2 and the second copper conductive layer 3 both have a thickness of 300–1000 nm. The second copper conductive layer 3 has the same structure as the first copper conductive layer 2.

[0027] like Figure 1 and Figure 2 As shown, the first leveling layer 5 includes a grid copper support layer 51, which is disposed on the upper surface of the first copper conductive layer 2. A second water-plated copper layer 52 is disposed on one side of the grid copper support layer 51 and on the upper surface of the tab 4. The second leveling layer 6 includes a water-plated copper support layer 61, which is disposed on the lower surface of the tab 4. A third water-plated copper layer 62 is disposed on one side of the water-plated copper support layer 61 and on the lower surface of the second copper conductive layer 3. The grid copper support layer 51 and the second water-plated copper layer 52 can make the upper surface of the composite copper foil flat, and the water-plated copper support layer 61 and the third water-plated copper layer 62 can make the lower surface of the composite copper foil flat.

[0028] Specifically, the grid copper support layer 51 is integrally water-plated with the second water-plated copper layer 52, and the water-plated copper support layer 61 is integrally water-plated with the third water-plated copper layer 62. By integrating the grid copper support layer 51 with the second water-plated copper layer 52 and the water-plated copper support layer 61 with the third water-plated copper layer 62, the stability of the connection between the substrate layer 1 and the tab 4 is improved.

[0029] Meanwhile, the mesh copper support layer 51 can save materials. Since the lower surface area of ​​the tab 4 is small, the mesh material-saving treatment of the water-plated copper support layer 61 is not required.

[0030] The first leveling layer 5 and the second leveling layer 6 are both formed by water-plated copper. The upper surface of the grid copper support layer 51 and the upper surface of the second water-plated copper layer 52 are on the same horizontal plane, and the lower surface of the water-plated copper support layer 61 and the lower surface of the third water-plated copper layer 62 are on the same horizontal plane.

[0031] The production process for all-metal tab composite copper foil rolls with a tab diameter of 20mm and a composite copper foil diameter of 260mm is as follows:

[0032] 1. Prepare a roll of substrate material of PET / PP / PI / PPS, etc. with a width of 1350mm and a thickness of 4.5μm. Load the material into the roll-up magnetron coating machine to perform copper plating on the A / B sides as a base layer to form a magnetron copper plating layer 201. Each A / B side is plated with copper with a thickness of 80±10nm. The running speed is 20m / min, with 14 copper targets on each side. The total power is controlled at 120±5kw, and the ion source cleaning voltage is 700V.

[0033] 2. The copper-plated film roll is fed to the water plating line. The A / B sides are water-plated once to quickly thicken the copper layer and form the first water-plated copper layer 202. The thickness of the A side is increased to 1000±50nm and the thickness of the B side is increased to 800±50nm. The unwinding tension is 90±10N, the winding tension is 80±10N, the speed is 12±2m / min, and the total current of the rectifier is 5500±500A.

[0034] 3. Apply acid-resistant ink layer 7 to side A of the water-plated roll material, with a printing thickness of 1-5μm, a line speed of 30±10m / min, a winding and unwinding tension of 100±20N, and a UV curing energy of 8000±1000 millijoules / square centimeter.

[0035] Acid-resistant ink covers a specific area of ​​surface A, protecting the copper layer in that area from further thickening during subsequent secondary water plating. This ensures that the non-ink area of ​​surface A has the same thickness as the tab. UV curing allows the ink to dry and solidify quickly, forming a stable protective coating that prevents the ink from peeling off in subsequent processes.

[0036] 4. Two rolls of pure copper foil tabs with a width of 44mm and a thickness of 6.5μm are rolled together on a roll-to-roll rewinding machine. The running speed is 100±30m / min, the unwinding tension is 100N±10N, and the winding tension can be adjusted adaptively by the equipment. The welding width is 2±1mm, the welding pressure is 0.4±0.1Mpa, and the amplitude is 40±10%.

[0037] Roll-to-roll welding enables continuous and rapid welding of electrode tabs and composite copper foil, which improves production efficiency compared to traditional welding methods.

[0038] 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 of ​​side A until it reaches the interface with the gas cylinder of the tab. Increase the thickness of side B by 200nm on top of the 800nm ​​thickness of 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±3% sodium hydroxide solution for 1-3 minutes at a temperature of 80±20℃. The unwinding tension is 80±10N, the winding tension is 70±10N, the speed is 10±2m / min, and the total current of the rectifier is 4500±500A.

[0039] 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.

[0040] 6. Finally, the material is fed 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±20N, and the winding tension can be adjusted adaptively by the machine. This yields 4 rolls of 20mm*260mm wide all-metal tab composite copper foil rolls.

[0041] Working principle: A leveling layer 5 covers the upper surface of the first copper conductive layer 2 and the tab 4, consisting of a grid copper support layer 51 and a second water-plated copper layer 52. A second leveling layer 6 covers the lower surface of the tab 4 and the lower surface of the second copper conductive layer 3, consisting of a water-plated copper support layer 61 and a third water-plated copper layer 62. The leveling layer formed by the water-plating copper process fills the height difference between the tab 4 and the copper conductive layer, making the surface of the composite copper foil flat. This prevents the tab from lifting off the edges of the copper foil during winding, improving winding quality and appearance. The leveling layer is tightly bonded to the tab and the copper conductive layer, not only eliminating the height difference but also further enhancing the connection strength between the tab and the composite copper foil, preventing the tab from falling off during use. The flat surface facilitates subsequent battery assembly, reduces installation difficulty, improves battery assembly accuracy and reliability, and reduces problems such as poor contact caused by uneven surfaces.

[0042] 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.

[0043] The preferred embodiments of this utility model disclosed above are merely illustrative of the present utility model. These preferred embodiments do not exhaustively describe all details, nor do they limit the utility model 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 this utility model, thereby enabling those skilled in the art to better understand and utilize it. This utility model is limited only by the claims and their full scope and equivalents.

Claims

1. A composite copper foil with all-metal tabs that is easy to wind up, characterized in that, It includes a substrate layer (1), a first copper conductive layer (2) is disposed on the upper surface of the substrate layer (1), a second copper conductive layer (3) is disposed on the lower surface of the substrate layer (1), a tab (4) is welded to the side of the substrate layer (1), a first filler layer (5) is disposed on the upper surface of the first copper conductive layer (2), and a second filler layer (6) is disposed on the lower surface of the tab (4).

2. The easily rewindable all-metal tab composite copper foil according to claim 1, characterized in that: The first copper conductive layer (2) includes a magnetron copper plating layer (201) and a first water-plated copper layer (202), wherein the magnetron copper plating layer (201) is disposed between the substrate layer (1) and the first water-plated copper layer (202).

3. The easily rewindable all-metal tab composite copper foil according to claim 1, characterized in that: The first filling layer (5) includes a grid copper support layer (51), which is disposed on the upper surface of the first copper conductive layer (2). A second water-plated copper layer (52) is disposed on one side of the grid copper support layer (51), which is disposed on the upper surface of the tab (4).

4. The easily rewindable all-metal tab composite copper foil according to claim 2, characterized in that: The second leveling layer (6) includes a water-plated copper support layer (61), which is disposed on the lower surface of the tab (4). A third water-plated copper layer (62) is disposed on one side of the water-plated copper support layer (61), which is disposed on the lower surface of the second copper conductive layer (3).

5. The easily rewindable all-metal tab composite copper foil according to claim 1, characterized in that: The thickness of the substrate layer (1) is 2.5 to 8 μm.

6. The easily rewindable all-metal tab composite copper foil according to claim 1, characterized in that: The thickness of the first copper conductive layer (2) and the second copper conductive layer (3) is 300-1000 nm.

7. The easily rewindable all-metal tab composite copper foil according to claim 1, characterized in that: The second copper conductive layer (3) has the same structure as the first copper conductive layer (2).

8. The easily rewindable all-metal tab composite copper foil according to claim 3, characterized in that: The upper surface of the grid copper support layer (51) is at the same level as the upper surface of the second water-plated copper layer (52).

9. The easily wound all-metal tab composite copper foil according to claim 4, characterized in that: The lower surface of the water-plated copper support layer (61) and the lower surface of the third water-plated copper layer (62) are on the same horizontal plane.

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