Method for producing a composite foil, production system and use thereof

Abstract

The application relates to a preparation method of a composite foil, a production system and application thereof. The preparation method of the composite foil comprises the following steps: S100, providing a composite base material, which comprises a first adhesive layer, a polymer base material layer, a second adhesive layer and a second release film which are sequentially stacked; S200, compositing a first foil layer on one side surface of the polymer base material layer through the first adhesive layer; S300, coating a support film on the surface of the first foil layer; S400, peeling off the second release film, and compositing a second foil layer on the other side surface of the polymer base material layer through the second adhesive layer; and S500, peeling off the support film, and preparing a double-sided composite foil; wherein the bonding force between the support film and the first foil layer is F1, the bonding force between the first adhesive layer and the first foil layer is F2, and F1 and F2 satisfy F1F2. The method is simple in operation, low in equipment cost, good in performance of the prepared composite foil, and wide in application prospect.

Description

Technical Field

[0001] This application relates to the field of multilayer composite material technology, and more specifically, to a method for preparing composite foil, a production system thereon, and its application. Background Technology

[0002] With the rapid development of 5G, consumer electronics, new energy vehicles, and energy storage, the demand for metal foil has increased rapidly. However, metal foil suffers from high production costs, high density, high weight ratio, and low battery safety and energy density. To reduce the use of metal, effectively lower the cost of battery current collectors, and improve the overall energy density and safety of batteries, the industry has developed current collectors composed of a polymer substrate layer and metal foil layers disposed on one or both sides of the polymer substrate layer. These are called composite current collectors, such as composite copper foil current collectors and composite aluminum foil current collectors.

[0003] Taking composite copper foil as an example, traditional composite copper foil is usually made using a two-step or three-step copper plating process. The two-step process involves first depositing a metal layer tens of nanometers thick onto the surface of a polymer film using magnetron sputtering, ensuring conductivity and good film density and adhesion. Then, electroplating is used to thicken the metal layer to the target thickness, such as 1 μm. The three-step process is based on the two-step process, adding vapor deposition before the electroplating step to accelerate metal layer deposition. Both the two-step and three-step methods suffer from complex and uncontrollable processes, poor uniformity of the composite copper foil, high equipment costs, limited equipment functionality, high production costs, and difficulty in mass production. Furthermore, methods for preparing composite foil by roll forming of foil and polymer substrates have been reported, but the adhesion between the two is poor, leading to easy detachment, and the thickness reaches extremely thin levels, making it difficult to control transmission stability and resulting in unsatisfactory composite effects.

[0004] Therefore, the industry urgently needs to develop a new method and apparatus for preparing composite foils, which should be able to simplify the composite production process, reduce equipment costs, and ensure uniform and stable composite of the foils while also possessing good performance. Summary of the Invention

[0005] Based on this, this application provides a novel method and production system for preparing composite foil, which simplifies the composite production process, reduces costs, and ensures uniform and stable composite formation of the foil while maintaining good performance. The technical solution is as follows:

[0006] A method for preparing a composite foil includes the following steps:

[0007] S100: Provide a composite substrate, the composite substrate comprising a first adhesive layer, a polymer substrate layer, a second adhesive layer and a second release film stacked sequentially;

[0008] S200: The first foil layer is laminated to one side surface of the polymer substrate layer through the first adhesive layer to prepare a single-sided composite foil intermediate-I;

[0009] S300: A support film is applied to the foil surface of the single-sided composite foil intermediate-I to prepare single-sided composite foil intermediate-II;

[0010] S400: Peel off the second release film from the single-sided composite foil intermediate-II, and laminate the second foil layer to the other side of the polymer substrate layer through the second adhesive layer to prepare the double-sided composite foil intermediate-I;

[0011] S500: Peel off the support film in the intermediate body-I of the double-sided composite foil to prepare a double-sided composite foil;

[0012] Wherein, the bonding force between the support film and the first foil layer is F1, and the bonding force between the first adhesive layer and the first foil layer is F2, and F1 and F2 satisfy: F1 < F2.

[0013] In one embodiment, the thickness of the support film is 15 μm to 50 μm.

[0014] In one embodiment, F2 / F1 ≥ 2.

[0015] In one embodiment, F1 is 0.2N / 25mm to 0.5N / 25mm.

[0016] In one embodiment, F2 ≥ 0.6 N / 25 mm. Further, F2 is 0.6 N / 25 mm to 5 N / 25 mm.

[0017] In one embodiment, the tensile strength of the support membrane is 150MPa~350MPa, the elongation at break is 80%~400%, and the tensile strength corresponding to a constant elongation of 3% is ≥40MPa.

[0018] In one embodiment, the material of the support membrane includes one or more combinations of polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polyimide (PI), polyamide (PA), polyester (PC), polyvinyl chloride (PVC), polystyrene (PS), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polybutylene terephthalate (PBT), acrylonitrile-styrene copolymer (SAN), acrylonitrile-butadiene-styrene terpolymer (ABS), polyarylsulfone (PASF), polyethylene naphthalate (PEN), poly(3,4-ethylenedioxythiophene) (PEDOT), polyaniline (PANI), and polypyrrole (PPy).

[0019] In one embodiment, the thickness of the polymer substrate layer is 1 μm to 6 μm.

[0020] In one embodiment, the thicknesses of the first adhesive layer and the second adhesive layer are independently 0.2 μm to 4 μm.

[0021] In one embodiment, the thicknesses of the first foil layer and the second foil layer are independently 0.8 μm to 3.5 μm.

[0022] In one embodiment, the first foil layer and the second foil layer are each independently one or more combinations of copper foil, aluminum foil, titanium foil, nickel foil, cadmium foil, iron foil and silver foil.

[0023] In one embodiment, the polymer substrate layer is made of one or more of the following materials: polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polyimide (PI), polyamide (PA), polyester (PC), polyvinyl chloride (PVC), polystyrene (PS), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polybutylene terephthalate (PBT), acrylonitrile-styrene copolymer (SAN), acrylonitrile-butadiene-styrene terpolymer (ABS), polyarylsulfone (PASF), polyethylene naphthalate (PEN), poly(3,4-ethylenedioxythiophene) (PEDOT), polyaniline (PANI), and polypyrrole (PPy).

[0024] In one embodiment, after step S200 and before S300, the following steps are further included:

[0025] The foil surface of the single-sided composite foil intermediate-I is brought into contact with a first passivation liquid for a first passivation treatment.

[0026] In one embodiment, after step S400 and before S500, the following steps are further included:

[0027] The double-sided composite foil intermediate-I is brought into contact with a second passivation liquid for a second passivation treatment.

[0028] This application also provides a composite foil production system for implementing the preparation method described above, comprising:

[0029] Unwinding system for unwinding multilayer composite materials;

[0030] A foil production system, including a cathode roller, is used to produce at least a foil layer;

[0031] A composite system, including a composite roller, is used to composite a polymer substrate layer, an adhesive layer, and a foil layer to obtain a composite foil.

[0032] A winding system, located downstream of the composite system, includes a support film unwinding device, a support film laminating device, a support film peeling and winding device, and a composite foil winding device; wherein, the support film unwinding device is used to unwind the support film, the support film laminating device is used to cover the support film onto the foil surface of the single-sided composite foil intermediate-I, the support film peeling and winding device is used to peel off and wind up the support film on the surface of the double-sided composite foil intermediate-I, and the composite foil winding device is used to wind up at least the single-sided composite foil intermediate-II and the double-sided composite foil;

[0033] In the process of preparing single-sided composite foil intermediate-I, the second release film is in contact with the surface of the composite pressure roller; the polymer substrate layer is transferred in the following path sequence: unwinding system, composite system, support film composite device and composite foil winding device;

[0034] In the process of preparing double-sided composite foil intermediate-I, before single-sided composite foil intermediate-II enters the composite system, the second release film on the surface is peeled off, and the support film contacts the surface of the composite pressure roller; the polymer substrate layer is transferred in the following path sequence: unwinding system, composite system, support film peeling and winding device, and composite foil winding device.

[0035] In one embodiment, according to the transport direction of the polymer substrate layer, the support film unwinding device is located on the side of the polymer substrate layer closer to the support film composite device; the composite foil winding device is located on the side of the polymer substrate layer away from the support film composite device.

[0036] Along a direction away from the support film unwinding device, the support film peeling and winding device is located beside the support film composite device and upstream of the composite foil winding device; the second foil layer in the double-sided composite foil intermediate-I faces the support film composite device, and the support film faces the support film peeling and winding device.

[0037] In one embodiment, the support film laminating device includes a first composite roller and a second composite roller that abut against each other, forming a composite roller group; during the support film laminating process, the support film contacts the roller surface of the first composite roller, and the second release film contacts the roller surface of the second composite roller, and the support film is applied to the foil surface of the single-sided composite foil intermediate-I by roller pressing; the support film peeling and winding device includes a support film peeling roller and a support film winding roller, both of which are located beside the composite roller group.

[0038] In one embodiment, the support film peeling roller and the support film winding roller are both located on one side of the first composite roller. During the support film peeling and winding process, the second foil layer contacts the roller surface of the first composite roller, and the support film contacts the roller surface of the peeling roller, so that the support film is peeled from the surface of the double-sided composite foil intermediate-I and transferred to the support film winding roller for winding.

[0039] In one embodiment, the unwinding system includes an unwinding device, a release film peeling device, and a release film winding device; wherein the unwinding device is used to unwind the multilayer composite material, the peeling device is used to peel off the release film and transfer it to the release film winding device for winding, and to transfer the polymer substrate layer and its surface adhesive layer downstream for lamination. Further, the unwinding system has an integrated unwinding and winding structure, wherein the unwinding device, the release film peeling device, and the release film winding device are integrated into a single design.

[0040] In one embodiment, the foil production system further includes an electrolytic cell for containing an electrolyte, the bottom of which is immersable in the electrolyte to form the foil layer on the surface of the cathode roller.

[0041] In one embodiment, the foil production system further includes a cleaning device for cleaning the foil layer on the surface of the cathode roller. The cleaning device and the composite pressure roller are arranged circumferentially along the cathode roller and are located on opposite sides of the cathode roller.

[0042] In one embodiment, the foil production system further includes a foil stripping roller for stripping the foil layer from the surface of the cathode roller. The foil stripping roller and the composite pressure roller are arranged circumferentially along the cathode roller and are located on opposite sides of the cathode roller. Further, the foil stripping roller and the cleaning device are located on the same side. Even further, the foil stripping roller is closer to the top of the cathode roller than the cleaning device.

[0043] In one embodiment, the foil production system further includes a foil passivation device located on the same side of the cathode roller as the foil stripping roller, for at least passivating the foil stripped from the surface of the cathode roller.

[0044] In one embodiment, the foil production system further includes a foil winding device located on the same side of the cathode roller as the foil stripping roller, for at least winding the foil stripped from the surface of the cathode roller.

[0045] In one embodiment, the foil system further includes a polishing device for polishing the surface of the cathode roller, the polishing device being disposed opposite to the cathode roller, located on the same side of the composite pressure roller, and closer to the bottom of the cathode roller.

[0046] In one embodiment, the composite foil production system further includes two or more composite foil conveying rollers to form a composite foil conveying roller assembly for conveying composite foil; the composite system and the unwinding system are located on the same side of the cathode roller, the winding system is located on the other side of the cathode roller, the composite foil conveying roller assembly is located around the unwinding system, and the composite foil forms a U-shaped conveying path around the unwinding system on the composite foil conveying roller assembly, with the U-shaped opening facing the winding system.

[0047] In one embodiment, the composite foil roller assembly includes a first composite foil roller assembly located below the unwinding system; and a second composite foil roller assembly located above the unwinding system; the composite foil is transported in the path sequence of the first composite foil roller assembly, the second composite foil roller assembly, and the winding system.

[0048] In one embodiment, the composite foil roller assembly further includes a third composite foil roller assembly located between the second composite foil roller assembly and the winding system, for adjusting the tension of the composite foil during the transmission process; the composite foil is transmitted in the path sequence of the first composite foil roller assembly, the second composite foil roller assembly, the third composite foil roller assembly, and the winding system.

[0049] In one embodiment, the composite foil production system further includes a frame assembly having a multi-layer frame structure for supporting the unwinding system, the first composite foil roller assembly, and the second composite foil roller assembly. The frame assembly is located beside the foil production system and the composite system, away from the winding system. The first composite foil roller assembly is located on the lower layer of the frame assembly, and the unwinding system and the second composite foil roller assembly are located on the upper layer of the frame assembly.

[0050] In one embodiment, the composite foil production system further includes a passivation system located downstream of the composite system and upstream of the winding system, for at least passivating the composite foil.

[0051] In one embodiment, the passivation system includes a first passivation device containing a first passivation liquid for performing a first passivation treatment on the composite foil intermediate. During the first passivation treatment, a single-sided foil layer of the composite foil intermediate acts as a liquid-coating layer in contact with the first passivation liquid. For a single-sided composite foil intermediate-I with a second adhesive layer and a second release film on one side, the single-sided foil layer also acts as an isolation layer to isolate the first passivation liquid from the second adhesive layer and the second release film on the back side.

[0052] In one embodiment, the passivation system further includes a second passivation device located downstream of the first passivation device along the transport direction of the composite foil intermediate. The second passivation device is used for secondary passivation of a single-sided foil layer, and / or transport, and / or passivation of a double-sided foil layer.

[0053] In one embodiment, the first passivation device is disposed between the first composite foil roller assembly; or, disposed between the second composite foil roller assembly; the composite foil intermediate is transported in the path sequence of the first composite foil roller assembly, the second composite foil roller assembly, and the winding system.

[0054] In one embodiment, the first passivation device is located between the first composite foil roller assembly and the second composite foil roller assembly, and the composite foil intermediate is transported in the following path sequence: the first composite foil roller assembly, the first passivation device, the second composite foil roller assembly, and the winding system.

[0055] In one embodiment, the first passivation device is located between the second composite foil roller assembly and the winding system, and the composite foil intermediate is transported in the following path sequence: first composite foil roller assembly, first passivation device, second composite foil roller assembly, first passivation device and winding system.

[0056] In one embodiment, the second passivation device is identical to the foil passivation device, but the foil peeling roller is positioned closer to the second passivation device relative to the composite system. Thus, the foil passivation device can be used both to passivate the foil and to transport or perform secondary passivation of the composite foil intermediate.

[0057] In one embodiment, the composite foil winding device is identical to the foil winding device, except that the foil peeling roller is positioned closer to the winding system relative to the composite system. Thus, the foil winding device can be used to wind both foil and the composite foil.

[0058] Another object of this application is to provide a composite current collector production system, including the composite foil production system described above.

[0059] This application has at least the following beneficial effects:

[0060] Compared to methods such as magnetron sputtering or electroplating on a substrate surface to form composite foils, or preparing composite foils containing a thick metal foil layer and then thinning the thick metal foil layer, this application utilizes the adhesive properties of the adhesive layer to directly composite foils (such as metal foil layers prepared by a foil-making device) with a polymer substrate layer to form composite foils. The foil layer is uniformly composited onto the surface of the polymer substrate layer, resulting in high composite strength and structural stability between the polymer substrate layer and the foil layer. Furthermore, the composite process is simpler, faster, and easier to control, eliminating the need for complex and expensive production equipment (such as sputtering and evaporation equipment), facilitating mass production and overcoming the difficulty in mass-producing composite foils, especially composite copper foils. Additionally, for extremely thin metal foils with poor mechanical properties and difficult peeling (such as 1μm copper foil), online composite with the polymer substrate layer followed by peeling is possible, eliminating the need for separate peeling, winding, transportation, and storage steps, thus improving production efficiency, reducing losses, and further lowering production costs.

[0061] Furthermore, according to the process and equipment of this application, the single-sided composite foil intermediate-I prepared by the first round of unwinding and lamination can be supported by the second release film for stable transport. In conjunction with the preparation of the single-sided composite foil intermediate-I by covering the foil surface with a support film before winding, a single-sided composite foil intermediate-II containing the support film is prepared and then wound. Thus, during the preparation of the double-sided composite foil, even if the second release film is peeled off after the second round of unwinding and before lamination, the single-sided composite foil intermediate can still be stably supported and stably transported to the lamination system, improving the lamination effect and reducing wrinkling and tape breakage. Furthermore, after the second round of lamination, the support film can also improve the transport stability of the double-sided composite foil film. It can be peeled off before the double-sided composite foil is wound, and the peeled support film can be reused.

[0062] Furthermore, while existing foil production equipment technology is relatively mature, its applications are somewhat limited. This application can directly utilize existing foil production equipment as the foil production system within a composite foil production system. By modifying the structure and / or position of the unwinding and laminating systems and / or the way the composite foil travels on the rollers, foil production and lamination can be integrated, further reducing equipment costs and floor space. Specifically, on the one hand, the composite foil production system of this application can either produce metal foil independently using existing foil production equipment, performing conventional passivation (optionally) and winding processes according to the original methods and routes, without being affected by the unwinding and laminating systems. On the other hand, the composite foil production system of this application can also utilize existing foil production equipment in conjunction with the unwinding and laminating systems to produce composite foil, further reducing equipment costs and space occupancy rates in the composite foil production system, and improving the utilization rate of existing foil production equipment.

[0063] Furthermore, the composite foil production system of this application has wide applicability and no special restrictions on the type and thickness of composite foil, and has broad application prospects. Attached Figure Description

[0064] Figure 1 This is a schematic diagram of a cross-section of an existing foil-making equipment;

[0065] Figure 2 This is a flowchart illustrating a method for preparing composite foil according to an embodiment of this application;

[0066] Figure 3 This is a cross-sectional schematic diagram of a composite foil production system according to an embodiment of this application, showing the material feeding sequence for preparing a single-sided composite foil intermediate;

[0067] Figure 4 This is a cross-sectional schematic diagram of a composite foil production system according to an embodiment of this application, showing the material feeding sequence for preparing a double-sided composite foil intermediate;

[0068] Figure 5 This is a schematic diagram of an unwinding system with an integrated unwinding and take-up structure according to an embodiment of this application;

[0069] Figure 6 This is a schematic diagram of an unwinding system with an integrated unwinding and take-up structure according to an embodiment of this application;

[0070] Figure 7 This is a partial structural schematic diagram of a traction mechanism according to an embodiment of this application;

[0071] Figure 8 This is a partial structural schematic diagram of a winding tension adjustment mechanism according to an embodiment of this application;

[0072] Figure 9 This is a partial structural schematic diagram of a winding tension adjustment mechanism according to an embodiment of this application;

[0073] Figure 10 This is a partial structural diagram of an unwinding system including a floating roller device according to an embodiment of this application;

[0074] Figure 11 This is a partial structural diagram of an unwinding system including a floating roller device according to an embodiment of this application;

[0075] Figure 12 This is a partial structural diagram of an embodiment of the unwinding system shown in this application;

[0076] Figure 13 This is a schematic diagram of the material feeding structure of an unwinding system with an integrated unwinding and take-up structure, as shown in an embodiment of this application.

[0077] Figure 14 This is a cross-sectional schematic diagram of a composite foil production system according to an embodiment of this application;

[0078] Figure 15 This is a cross-sectional schematic diagram of a composite foil production system according to an embodiment of this application;

[0079] Figure 16 This is a cross-sectional schematic diagram of the first passivation device according to an embodiment of this application;

[0080] Figure 17 This is a cross-sectional schematic diagram of a composite foil production system according to an embodiment of this application, showing the material feeding sequence for preparing a single-sided composite foil intermediate;

[0081] Figure 18 This is a cross-sectional schematic diagram of a composite foil production system according to an embodiment of this application, showing the material feeding sequence for preparing a double-sided composite foil intermediate;

[0082] Figure 19 This is a cross-sectional schematic diagram of a composite foil production system according to an embodiment of this application, showing the material feeding sequence for preparing a single-sided composite foil intermediate;

[0083] Figure 20 This is a cross-sectional schematic diagram of a composite foil production system according to an embodiment of this application, showing the material feeding sequence for preparing a single-sided composite foil intermediate;

[0084] Figure 21 This is a cross-sectional schematic diagram of a composite foil production system according to an embodiment of this application, showing the material feeding sequence for preparing a single-sided composite foil intermediate;

[0085] Figure reference numerals: 1. Foil forming equipment / foil forming system; 11. Cathode roller; 12. Electrolytic cell; 13. Foil peeling roller; 14. Foil passivation device; 1401. Foil passivation tank; 1402. Foil flattening roller; 1403. First tension roller; 1404. Foil passivation liquid roller; 1405. Foil squeezing roller; 1406. Foil drying oven; 15. Foil winding device; 15. Foil winding flattening roller; 1501. Foil winding tension roller; 1502. Foil winding over roller; 1503. Foil winding roller; 1504. Cleaning device; 16. Polishing device; 17. Composite foil production system F1; 1000. Unwinding system; 1100. Main support; 1110. Base; 1120. Main wall panel; 1130. Upper base plate; 1200. Unwinding device / unwinding column; 1200. Winding device / winding... 1300 roll body, 1400 multi-layer composite material guide roller, 1400A multi-layer composite material guide roller, 1400B peeling guide roller, 1400C third guide roller, 2000 multi-layer composite material with release film on both sides, 2100 release film, 2100-1 first release film, 2100-2 second release film, 2200 polymer substrate layer with adhesive surface, 100 winding tension adjustment mechanism, 110 proximity pressure roller, 120 first drive mechanism, 121 first power mechanism, 122 transfer base plate, 123 first slide rail, 124 gear, 125 rack, 130 second drive mechanism, 131 second power mechanism, 132 base slider, 133 second slide rail, 140 transfer roller, 141 transfer roller bracket, 2 support rods 02, Reinforcing rod 203, First correction mechanism 220, First guide assembly 221, Lower base plate 222, Second correction mechanism 230, Second guide assembly 231, Top plate 232, Release film peeling device 300A, Traction mechanism 300, Drive roller body 310, Arrangement wall panel 320, Quick release opening 321, Limiting top block 322, Auxiliary positioning plate 324, Quick release mounting plate 330, Traction drive motor 340, Traction roller 350, Guide drive mechanism 351, Fixed rod 360, Floating roller device 400, Limiting block 401, Floating roller mounting main plate 410, Floating roller body 420, Rotating shaft 430, Counterweight assembly 440, Counterweight rod 441, Weight 442, Floating roller drive mechanism 450, Composite system 2, Guide roller 21 22. Second tension roller; 23. Composite pressure roller; 24. Composite foil peeling roller; 3. Composite foil passing roller; 31. First composite foil passing roller assembly; 3101 and 3102 of the first composite foil passing roller; 32. Second composite foil passing roller assembly; 3201 and 3202 of the second composite foil passing roller; 4. Passivation system; 45. First passivation device; 45. Single roller coating mechanism; 4501, first liquid receiving tray; 45011, first liquid receiving roller; 45012, multi-roller coating mechanism; 4502, second liquid receiving tray; 45021, second liquid receiving roller; 45022, third liquid receiving roller; 45024, drip coating mechanism; 4503, dripping machine; 45032, uniform liquid roller; 46. Second passivation device.41. Composite foil passivation groove; 42. Composite foil traction roller; 43. Composite foil passivation roller; 44. Composite foil squeeze roller; 5. Rewinding system; 51. Composite foil rewinding tension roller; 52. Support film unwinding device / support film unwinding roller; 53. Support film composite device; 531. First composite roller; 532. Second composite roller; 54. Support film peeling and rewinding device; 541. Support film peeling roller group; 5411. Support film peeling roller No. 1; 5412. Support film peeling roller No. 2; 542. Support film rewinding roller; 55. Composite foil rewinding device / composite foil rewinding roller; 2300 foil layer; 2300-1 first foil layer; 2300-2 second foil layer; 2400 support film; 2500-1 single-sided composite foil intermediate; 2500-2 single-sided composite foil intermediate; 2500-2 double-sided composite foil intermediate; 2300-1 double-sided composite foil intermediate. 2600-1, Finished double-sided composite foil material 2600-2. Detailed Implementation

[0086] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of this application. This application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of this application. For better illustration of the following embodiments, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product; it will be understood by those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0087] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this application and in its specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0088] In this application, "and / or" includes any and all combinations of one or more of the associated listed items. The terms "comprising," "having," and "including" as used in this application are intended to cover non-exclusive inclusion, unless explicit qualifying terms such as "only," "consisting of," etc., are used, in which case another component may be added.

[0089] In this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc. Similarly, "several" refers to one or more, including one, two, or more; "at least one" refers to one or more, including one, two, or more; and "multiple" refers to two or more, including two, three, or more, unless otherwise explicitly specified.

[0090] In this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, the orientation or positional relationship indicated by these terms is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description, and is not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0091] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0092] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0093] In this application, it should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intermediate element. If an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element present. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0094] In this application, multilayer composite material refers to a composite material composed of two or more materials with different chemical compositions, which are tightly bonded together in a layered structure by physical or chemical methods, including one or more combinations of composite substrates, single-sided composite foils and double-sided composite foils.

[0095] For example, in this application, "composite substrate" includes a single-sided composite substrate with a polymer substrate layer and a release film on one side of the substrate, and a double-sided composite substrate with a polymer substrate layer and release films on both sides of the substrate.

[0096] For example, in this application, "single-sided composite foil" refers to a composite foil with a foil layer on only one surface of the polymer substrate layer, such as: ① a single-sided composite foil with a three-layer structure, specifically a polymer substrate layer, an adhesive layer, and a foil layer stacked sequentially; ② a single-sided composite foil (intermediate) with a five-layer structure, specifically a first release film, a first adhesive layer, a polymer substrate layer, a second adhesive layer, and a foil layer stacked sequentially. "Double-sided composite foil" refers to a composite foil with foil layers on both surfaces of the polymer substrate layer. The "composite foil" described in this application includes both intermediate and finished composite foil products.

[0097] Furthermore, in this application, the unwinding system in the composite foil production system mainly refers to a single-sided composite foil intermediate with one side of a double-sided composite substrate or a polymer substrate layer having a foil and a support film on one side and a release film on the other side.

[0098] In this application, for a double-sided composite release film substrate, such as a composite substrate containing a first release film and a second release film, after the first release film is peeled off, the exposed adhesive layer on that side is bonded to the foil layer. That is, relative to the second release film, the first release film is closer to the release film winding device and farther away from the composite system, while the second release film is in contact with the composite pressure roller.

[0099] In this application, "immersion" means that an object is partially or completely submerged in a liquid; "submersion" means that an object is completely submerged in a liquid, below the liquid surface.

[0100] With the booming development of the new energy industry, metal foil, as a key material for lithium battery current collectors, has experienced explosive growth. Among them, copper foil, as a key material for lithium battery negative electrode current collectors, is mainly prepared by electrolytic (ED) and rolling (RA) methods. Currently, electrolytic copper foil has a market share of over 90%, dominating lithium battery applications.

[0101] Commonly adopted in the industry Figure 1 The foil-making equipment 1 shown produces electrolytic copper foil. The foil-making equipment 1 mainly includes a cathode roller 11, an electrolytic cell 12 (optionally, some electrolytic cells 12 are buried underground), a foil peeling roller 13, a foil passivation device 14, a foil passivation tank 1401, a foil flattening roller 1402, a foil tension roller 1403, a foil passivation liquid roller 1404, a foil squeezing roller 1405, a foil drying box 1406, a foil winding device 15, a foil winding flattening roller 1501, a foil winding tension roller 1502, a foil winding over roller 1503, and a foil winding roller 1504. Understandably, the downstream of the foil peeling roller 13, such as the foil passivation device 14 and the foil winding device 15, can be considered as the post-processing side. Optionally, the foil passivation device 14 and the foil winding device 15, except for the foil winding roller 1504, are all arranged on the passivation assembly bracket (shown in the figure but not marked). The electrolytic cell 12 is used to contain the electrolyte. The bottom of the cathode roller 11 can be immersed in the electrolyte to form a foil layer on the surface of the cathode roller 11. The foil layer is peeled off from the surface of the cathode roller 11 by the foil peeling roller 13 and transferred to the downstream foil passivation device 14. The foil passivation tank 1401 is filled with passivation liquid. The foil is transferred to the foil passivation tank 1401 by the foil flattening roller 1402, the first tension roller 1403 and the foil passivation liquid lower roller 1404. The foil is immersed in the passivation liquid for passivation treatment. Then the passivation liquid is removed by the foil squeezing roller 1405 and it enters the foil drying box 1406 for drying. The passivated foil enters the foil winding device 15. Specifically, the passivated and dried foil is transferred to the foil winding roller 1504 for winding by the foil winding flattening roller 1501, the foil winding tension roller 1502 and the foil winding over roller 1503. Further, see Figure 1 The foil production equipment 1 may also include a cleaning device 16, mainly comprising an acid-extrusion roller, a spray roller, and an air shower pipe (not specifically shown in the figure). The acid-extrusion roller, spray roller, and air shower pipe are arranged circumferentially around the cathode roller 11 and distributed sequentially from low to high along the direction away from the bottom of the electrolytic cell 12, mainly used to improve the cleanliness of the foil surface. In addition, the foil production equipment 1 may also include a polishing device 17 for polishing the surface of the cathode roller 11.

[0102] As electrical products trend towards thinner, lighter, lower-cost, and safer products, metal foils, especially copper foils, are no longer sufficient due to their high density. To address this, researchers have developed composite current collectors composed of a polymer substrate and a composite metal foil on its surface. Compared to metal foil current collectors, composite current collectors offer significant advantages in cost, safety performance, and improved battery energy density, and theoretically have greater potential for thinning, attracting widespread attention. On the one hand, with the rise of composite current collectors, the growth trend of metal foils (such as copper foil) has slowed, leading to a decrease in the operating rate (or utilization rate) of many foil-making equipment, and even idleness. On the other hand, the significant differences between the substrate and the metal make composite bonding difficult. Taking composite copper foil as an example, traditional composite copper foil is typically produced using two-step and three-step copper plating processes, both of which suffer from complex processes, low production efficiency, uncontrollable processes, poor uniformity of the composite copper foil, high equipment costs, and are usually only applicable to the production of composite copper foil, resulting in high production costs and difficulty in mass production.

[0103] Based on this, this application provides a new method and production system for preparing composite foil, which can simplify the composite production process, reduce equipment costs, and ensure the performance of the composite foil, including but not limited to composite stability, mechanical properties, and corresponding electrical properties required as a current collector.

[0104] See Figure 2 One embodiment of this application provides a method for preparing a composite foil, comprising the following steps:

[0105] S100: Provide a composite substrate, the composite substrate comprising a first adhesive layer, a polymer substrate layer 2200, a second adhesive layer and a second release film 2100-2 stacked sequentially;

[0106] S200: The first foil layer 2300-1 is laminated to one side surface of the polymer substrate layer 2200 through the first adhesive layer to prepare a single-sided composite foil intermediate - I 2500-1;

[0107] S300: A support film 2400 is applied to the foil surface of the single-sided composite foil intermediate-I 2500-1 to prepare single-sided composite foil intermediate-II 2500-2;

[0108] S400: Peel off the second release film 2100-2 from the single-sided composite foil intermediate - II 2500-2, and bond the second foil layer 2300-2 to the other side surface of the polymer substrate layer 2200 through the second adhesive layer to prepare the double-sided composite foil intermediate - I 2600-1;

[0109] S500: Peel off the support film 2400 in the double-sided composite foil intermediate - I 2600-1 to prepare double-sided composite foil 2600-2;

[0110] The bonding force between the support film 2400 and the first foil layer 2300-1 is F1, and the bonding force between the first adhesive layer and the first foil layer 2300-1 is F2. F1 and F2 satisfy: F1 < F2.

[0111] The single-sided composite foil intermediate -I 2500-1, prepared by the first round of unwinding and lamination, can be stably transported with the support of the second release film 2100-2. Before winding the single-sided composite foil intermediate -I 2500-1, a support film 2400 is applied to the foil surface to prepare the single-sided composite foil intermediate -II 2500-2 containing the support film 2400 before winding. Thus, during the preparation of the double-sided composite foil, even if the second release film 2100-2 is peeled off after the second round of unwinding and before lamination, the single-sided composite foil intermediate can still be stably supported and stably transported to the lamination system 2, improving the lamination effect and reducing wrinkling and tape breakage. Furthermore, after the second round of lamination, the support film 2400 can also improve the transport stability of the double-sided composite foil intermediate -I 2600-1 film material. It can be peeled off before the finished double-sided composite foil 2600-2 is wound, and the peeled support film 2400 can be reused.

[0112] In one embodiment, the thickness of the support film 2400 is 15μm to 50μm, including but not limited to 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, or 50μm. This configuration improves the transport stability of the single-sided composite foil intermediate-I 2500-1 and the winding stability of the single-sided composite foil intermediate-II 2500-2. Furthermore, during the preparation of the double-sided composite foil intermediate-I 2600-1, the support film 2400 of appropriate thickness contacts the composite pressure roller 23, preventing the composite pressure roller 23 from adversely affecting the polymer substrate layer 2200 and the first foil layer 2300-1, and also contributing to the transport stability of the double-sided composite foil intermediate-I 2600-1.

[0113] In one embodiment, F2 / F1 ≥ 2, which is more conducive to the smooth progress of step S500 and avoids breakage or shrinkage of the double-sided composite foil. Understandably, the ratio of F2 / F1 is including but not limited to 2, 3, 4, 5, 6, 7, 8, 9 or 10.

[0114] Furthermore, F2≥0.6N / 25mm, which is more conducive to the stable composite of the first foil layer 2300-1 and the polymer substrate layer 2200. At the same time, it is more conducive to the smooth progress of the S500 peeling support film 2400 step, and avoids the breakage or shrinkage of the double-sided composite foil. Furthermore, F2 is 0.6N / 25mm to 5N / 25mm, including but not limited to: 0.6N / 25mm, 0.7N / 25mm, 0.8N / 25mm, 0.9N / 25mm, 1.0N / 25mm, 1.2N / 25mm, 1.5N / 25mm, 1.6N / 25mm, 1.8N / 25mm, 2.0N / 25mm, 2.1N / 25mm, 2.4N / 25mm, 2.5N / 25mm, 2.7N / 25mm, 3.0N / 25mm, 3.2N / 25mm, 3.5N / 25mm, 3.6N / 25mm, 3.9N / 25mm, 4.0N / 25mm, 4.2N / 25mm, 4.5N / 25mm, 4.8N / 25mm, or 5N / 25mm.

[0115] For example, F1 is 0.2N / 25mm to 0.5N / 25mm. In this way, the support film 2400 can be temporarily and effectively bonded to the surface of the first foil layer 2300-1. This facilitates the smooth progress of step S400 and improves the transport stability of the double-sided composite foil intermediate -I 2600-1. Simultaneously, it further facilitates the smooth progress of step S500, which involves peeling off the support film 2400, and prevents breakage or shrinkage of the double-sided composite foil. It is understood that F1 includes, but is not limited to, 0.2N / 25mm, 0.3N / 25mm, 0.4N / 25mm, or 0.5N / 25mm.

[0116] In one embodiment, the tensile strength of the support film 2400 is 150 MPa to 350 MPa, which facilitates the smooth progress of step S400 and improves the transport stability of the double-sided composite foil intermediate -I 2600-1. It is understood that the tensile strength of the support film 2400 includes, but is not limited to, 150 MPa, 180 MPa, 190 MPa, 200 MPa, 210 MPa, 230 MPa, 250 MPa, 280 MPa, 290 MPa, 300 MPa, 320 MPa, or 350 MPa.

[0117] In one embodiment, the elongation at break of the support film 2400 is 80% to 400%, which facilitates the smooth progress of step S400 and the transport stability of the double-sided composite foil intermediate - I 2600-1. It is understood that the elongation at break of the support film 2400 may include, but is not limited to, 80%, 90%, 100%, 120%, 150%, 180%, 200%, 220%, 250%, 300%, 350%, or 400%.

[0118] In one embodiment, the tensile strength of the support film 2400 at a constant elongation of 3% is ≥40 MPa. This facilitates the smooth progress of step S400 and improves the transport stability of the double-sided composite foil intermediate -I 2600-1. It is understood that the tensile strength of the support film 2400 at a constant elongation of 3% includes, but is not limited to, 40 MPa, 50 MPa, 80 MPa, 90 MPa, 100 MPa, 110 MPa, 120 MPa, 130 MPa, 140 MPa, or 150 MPa.

[0119] In one embodiment, the support film 2400 is made of one or more of the following materials: polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polyimide (PI), polyamide (PA), polyester (PC), polyvinyl chloride (PVC), polystyrene (PS), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polybutylene terephthalate (PBT), acrylonitrile-styrene copolymer (SAN), acrylonitrile-butadiene-styrene terpolymer (ABS), polyarylsulfone (PASF), polyethylene naphthalate (PEN), poly3,4-ethylenedioxythiophene (PEDOT), polyaniline (PANI), and polypyrrole (PPy). Exemplarily, the support film 2400 is made of PET, PE, or PP.

[0120] Understandably, metal foil is prone to oxidation and discoloration. Passivation treatment can prevent oxidation of the composite foil during winding, transport, and use. Optionally, after step S200 and before S300, the following step is included: contacting the foil surface of the single-sided composite foil intermediate - I 2500-1 with a first passivation solution for a first passivation treatment. Similarly, after step S400 and before S500, the following step is included: contacting the double-sided composite foil intermediate - I 2600-1 with a second passivation solution for a second passivation treatment.

[0121] Understandably, this application does not impose any special limitations on the material and thickness of the polymer substrate layer 2200. Optionally, the polymer substrate layer 2200 includes one or more combinations of polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polyimide (PI), polyamide (PA), polyester (PC), polyvinyl chloride (PVC), polystyrene (PS), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polybutylene terephthalate (PBT), acrylonitrile-styrene copolymer (SAN), acrylonitrile-butadiene-styrene terpolymer (ABS), polyarylsulfone (PASF), polyethylene naphthalate (PEN), poly3,4-ethylenedioxythiophene (PEDOT), polyaniline (PANI), and polypyrrole (PPy). Exemplarily, the polymer substrate layer 2200 is PET or PP. Optionally, the thickness of the polymer substrate layer 2200 is 1μm to 6μm, including but not limited to: 1μm, 1.9μm, 2μm, 2.5μm, 3μm, 3.5μm, 4μm, 4.5μm, 5μm, 5.5μm, or 6μm. Further, the thickness of the polymer substrate layer 2200 is independently 1.9μm to 5μm.

[0122] Understandably, this application does not impose any special limitations on the composition and thickness of the adhesive layer on the surface of the polymer substrate layer 2200. Optionally, the first adhesive layer and the second adhesive layer respectively comprise one or more combinations of rosin resin, terpene resin, petroleum resin, polyurethane resin, polyacrylic resin, epoxy resin, phenolic resin, polyester resin, polyimide, organosilicon polymers and their modified compounds, and polyolefins and their modified compounds. Exemplarily, the first adhesive layer and the second adhesive layer each independently comprise polyurethane. Optionally, the thicknesses of the first adhesive layer and the second adhesive layer are independently between 0.2 μm and 4 μm, including but not limited to: 0.2 μm, 0.25 μm, 0.3 μm, 0.35 μm, 0.4 μm, 0.45 μm, 0.5 μm, 0.55 μm, 0.6 μm, 0.7 μm, 0.75 μm, 0.8 μm, 0.85 μm, 0.9 μm, 1 μm, 1.9 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, or 4 μm. Further, the thicknesses of the first adhesive layer and the second adhesive layer are independently between 0.2 μm and 2 μm.

[0123] Understandably, this application does not impose any special limitations on foil layer 2300. Optionally, the first foil layer 2300-1 and the second foil layer 2300-2 are each independently composed of one or more of copper foil, aluminum foil, titanium foil, nickel foil, cadmium foil, iron foil, and silver foil. Exemplarily, both the first foil layer 2300-1 and the second foil layer 2300-2 are copper foil. Optionally, the thickness of the first foil layer 2300-1 and the second foil layer 2300-2 are each independently 0.8 μm to 3.5 μm, including but not limited to: 0.8 μm, 0.85 μm, 0.9 μm, 1 μm, 1.9 μm, 2 μm, 2.5 μm, 3 μm, or 3.5 μm. Further, the thickness of the first foil layer 2300-1 and the second foil layer 2300-2 are each independently 0.8 μm to 2.5 μm.

[0124] Understandably, in addition to comprising a first adhesive layer, a polymer substrate layer 2200, a second adhesive layer, and a second release film 2100-2 stacked sequentially, the composite substrate may also have a first release film 2100-1 disposed on the surface of the first adhesive layer. For a composite substrate containing a first release film 2100-1, step S200 includes: peeling off the first release film 2100-1 from the composite substrate, and bonding a first foil layer 2300-1 to one side surface of the polymer substrate layer 2200 through the first adhesive layer to prepare a single-sided composite foil intermediate - I 2500-1.

[0125] In one embodiment, the adhesive forces between the first adhesive layer and the polymer substrate layer 2200, and between the second adhesive layer and the polymer substrate layer 2200, are each independently 3N / 25mm to 30N / 25mm, including but not limited to: 3N / 25mm, 4N / 25mm, 5N / 25mm, 6N / 25mm, 7N / 25mm, 8N / 25mm, 9N / 25mm, 10N / 25mm, 15N / 25mm, 20N / 25mm, 25N / 25mm, or 30N / 25mm.

[0126] Understandably, this application does not impose any special restrictions on the material and thickness of the first release film 2100-1 and the second release film 2100-2. Optionally, the first release film 2100-1 and the second release film 2100-2 are each independently selected from one or more combinations of PET, PP, PVC, PE, pearlescent film, synthetic paper, and thermal synthetic paper. Further, the release force of the first release film 2100-1 and the second release film 2100-2 are each independently 5gf / 25mm to 30gf / 25mm.

[0127] See Figures 3-4 One embodiment of this application provides a composite foil production system F1 that can be used to implement the above-described composite foil preparation method, comprising:

[0128] An unwinding system 1000 is used to unwind a multilayer composite material 2000, which includes a polymer substrate layer 2200 with an adhesive surface and release films 2100 adhered to both sides of the substrate. The unwinding system 1000 includes an unwinding device 1200, a release film peeling device 300A, and a release film winding device 1300. The unwinding device 1200 is used to unwind the multilayer composite material 2000. During the first round of unwinding, the release film peeling device 300A is used to peel off the first release film 2100-1 and transfer it to the release film winding device 1300 for winding, and to transfer the polymer substrate layer 2200, its surface adhesive layer, and the second release film 2100-2 to the downstream for lamination.

[0129] The foil production system 1 includes a cathode roller 11 and an electrolytic cell 12. The electrolytic cell 12 is used to contain an electrolyte, and the bottom of the cathode roller 11 can be immersed in the electrolyte to form a foil layer on the surface of the cathode roller 11.

[0130] The composite system 2 includes a composite pressure roller 23, which abuts against the roller surface of the cathode roller 11, for composite polymer substrate layer 2200, adhesive layer and foil layer to obtain composite foil intermediate;

[0131] Several composite foils pass through roller 3, which are used to transfer at least the composite foil intermediates, including single-sided composite foil intermediate - I2500-1 and double-sided composite foil intermediate - I2600-1;

[0132] The winding system 5, located downstream of the composite system 2, includes a support film unwinding device 52, a support film composite device 53, a support film peeling and winding device 54, and a composite foil winding device 55. The support film unwinding device 52 is used to unwind the support film; the support film composite device 53 is used to cover the support film 2400 onto the foil surface (i.e., the first foil layer 2300-1) of the single-sided composite foil intermediate-I 2500-1; the support film peeling and winding device 54 is used to peel and wind up the support film 2400 on the surface of the double-sided composite foil intermediate-I 2600-1; and the composite foil winding device 55 is used to wind up at least the single-sided composite foil intermediate-II 2500-2 and the double-sided composite foil finished product 2600-2.

[0133] The working principle of the composite foil production system F1 is as follows:

[0134] (1) Preparation of single-sided composite foil material by first-round unwinding, raw foil, lamination, and rewinding:

[0135] The multilayer composite material unwound by the unwinding device 1200 is a composite substrate, comprising a first release film 2100-1, a first adhesive layer, a polymer substrate layer 2200, a second adhesive layer, and a second release film 2100-2 stacked sequentially. After unwinding, the release film peeling device 300A peels off the first release film 2100-1 and transfers it to the release film winding device 1300 for winding. The first adhesive layer, the polymer substrate layer 2200, the second adhesive layer, and the second release film 2100-2 are transferred to the downstream composite system 2 for lamination. The composite system 2 laminates the first foil layer 2300-1 onto the surface of the first adhesive layer to prepare a single-sided composite foil intermediate -I2500-1. During the lamination process, the second release film 2100-2 contacts the surface of the composite pressure roller 23. Under the action of the composite foil passing roller 3, the single-sided composite foil intermediate -I 2500-1 is transferred downstream, and the support film unwinding device 52 unwinds the support film 2400. The support film 2400 faces the foil side of the single-sided composite foil intermediate-I 2500-1 (i.e., the first foil layer 2300-1), and enters the support film composite device 53 simultaneously with the single-sided composite foil intermediate-I 2500-1 to be composited to prepare the single-sided composite foil intermediate-II 2500-2, and then is wound up at the downstream composite foil winding device 55.

[0136] Understandably, see Figure 3 In the process of preparing the single-sided composite foil intermediate-II 2500-2, the polymer substrate layer 2200 is transported in the following order: unwinding system 1000, composite system 2, support film composite device 53, and composite foil winding device 55; the first foil layer 2300-1 is transported in the following order: green foil system 1, composite system 2, support film composite device 53, and composite foil winding device 55; the support film 2400 is transported in the following order: support film unwinding device 52, support film composite device 53, and composite foil winding device 55; in addition, it can be understood that for composite substrates without the first release film 2100-1, the operation of peeling and winding the first release film 2100-1 is omitted.

[0137] (2) Second round of unwinding, foil preparation, lamination, and winding to prepare double-sided composite foil:

[0138] See Figure 4The single-sided composite foil intermediate -II 2500-2, which was wound up in (1), was unwound as a multilayer composite material. Before entering the composite system 2, the second release film 2100-2 was peeled off by the release film peeling device 300A and transferred to the release film winding device 1300 for winding. The second adhesive layer, the polymer substrate layer 2200, the first adhesive layer, the first foil layer 2300-1, and the support film 2400 were transferred to the downstream composite system 2 for composite. The composite system 2 composited the second foil layer 2300-2 onto the surface of the second adhesive layer to prepare the double-sided composite foil intermediate -I 2600-1. During the composite process, the support film 2400 was in contact with the roller surface of the composite pressure roller 23. Under the action of the composite foil passing roller 3, the double-sided composite foil intermediate -I 2600-1 is transferred to the downstream support film peeling and winding device 54, where the support film 2400 is peeled off and wound up. The double-sided composite foil finished product 2600-2 without the outer support film 2400 is then wound up at the downstream composite foil winding device 55.

[0139] Understandably, see Figure 4 In the process of preparing the double-sided composite foil finished product 2600-2, the polymer substrate layer 2200 is transported in the following order: unwinding system 1000, composite system 2, support film peeling and winding device 54, and composite foil winding device 55; the second foil layer 2300-2 is transported in the following order: raw foil system 1, composite system 2, support film peeling and winding device 54, and composite foil winding device 55; the support film 2400 is transported in the following order: unwinding system 1000, composite system 2, and support film peeling and winding device 54.

[0140] The composite foil production system F1 can directly composite foil (such as metal foil layers prepared by a foil-making device) with a polymer substrate layer 2200 online to form a composite foil, ensuring that the foil layer is uniformly composited on the surface of the polymer substrate layer 2200. This results in high composite strength and structural stability between the polymer substrate layer 2200 and the foil layer 2300. Furthermore, the composite process is simpler, faster, and easier to control, eliminating the need for complex and expensive production equipment (such as sputtering and evaporation equipment), facilitating mass production and overcoming the difficulty in mass-producing composite foils, especially composite copper foils. Additionally, for extremely thin metal foils with poor mechanical properties and difficult peeling (such as 1μm copper foil), separate peeling, winding, transportation, and storage steps are eliminated, improving production efficiency, reducing losses, and further lowering production costs.

[0141] To better describe this application, the following sections provide a more detailed description of each functional unit of the composite foil production system F1, including the structure of the functional units and the relationships between different functional units.

[0142] (1) Unwinding system 1000:

[0143] This application does not impose any special restrictions on the unwinding system 1000; a traditional unwinding device can be used, or Figures 3-6 The unwinding system 1000 shown has an integrated unwinding and take-up structure.

[0144] For example, this application adopts Figures 3-6 The unwinding system 1000 shown has an integrated unwinding and take-up structure for unwinding multilayer composite materials. In addition to the unwinding device 1200, the release film peeling device 300A, and the release film take-up device 1300, the unwinding system 1000 also includes: several multilayer composite material guide rollers 1400 and a main support 1100. The multilayer composite material guide rollers 1400 are used to transport the film material, and the main support 1100 is used to arrange related functional components, such as the unwinding device 1200, the release film peeling device 300A, and the release film take-up device 1300. Furthermore, the multilayer composite material guide roller 1400 includes a multilayer composite material guide roller 1400A and a peeling roller 1400B. The peeling roller 1400B and the traction mechanism 300 together form a release film peeling device 300A. After unwinding, the multilayer composite material 2000 is sequentially transported along the path of the unwinding device 1200, the multilayer composite material guide roller 1400A, and the peeling roller 1400B. The traction mechanism 300 pulls the single-sided release film 2100 to peel off from the multilayer composite material 2000 and transport it to the release film winding device 1300 for winding. The peeling roller 1400B transports the composite base film, which contains at least a polymer substrate layer 2200 and a surface adhesive layer, downstream for lamination. Optionally, in order to better control the tension of the multilayer composite material during the transport process and to transport the multilayer composite material smoothly and effectively, a third guide roller 1400C can also be provided as needed.

[0145] Understandably, the unwinding device 1200 includes an unwinding column 1200, and the winding device 1300 includes a winding column 1300. Further, the unwinding column 1200 includes an unwinding shaft. When the unwinding shaft is covered with a composite substrate, the unwinding column 1200 is formed by the unwinding shaft and its outer composite substrate; or when the unwinding shaft is covered with a single-sided composite foil, the unwinding column 1200 is formed by the unwinding shaft and its outer single-sided composite foil. When the unwinding shaft has no outer composite substrate or single-sided composite foil, the unwinding column 1200 is simply the unwinding shaft. Similarly, the winding column 1300 includes a winding shaft. When the winding shaft is covered with a release film, the winding column 1300 is formed by the winding shaft and its outer release film; when the winding shaft has no outer release film, the winding column 1300 is simply the winding shaft. For the sake of brevity, in this application, the unwinding column and the unwinding device can be used interchangeably, and the winding column and the winding device can be used interchangeably.

[0146] See Figures 6-7The traction mechanism 300 includes a drive roller 310, a traction roller 350, and a mounting wall plate 320. The ends of both the drive roller body 310 and the traction roller 350 are mounted on the mounting wall plate 320, with the traction roller 350 located below the drive roller body 310. The drive roller body 310 and the traction roller 350 cooperate to clamp and pull the release film 2100, transferring it to the winding device 1300. The mounting wall plate 320 is detachably mounted on the main support 1100. Exemplarily, the traction mechanism 300 is located vertically (i.e., longitudinally in the winding and unwinding integrated device) between the unwinding column 1200 and the winding column 1300, and horizontally on the side of the main support 1100 closest to the composite system 2.

[0147] See Figure 7 The end of the drive roller body 310 is mounted on the arrangement wall panel 320 via a quick-release mounting plate 330. A quick-release opening 321 is provided on the edge side of the arrangement wall panel 320. The quick-release mounting plate 330 is detachably mounted on the arrangement wall panel 320, and its side is engaged with the quick-release opening 321. The end of the drive roller body 310 is fixed to the corresponding quick-release mounting plate 330. The drive roller body 310 is driven to rotate by a traction drive motor 340, which is mounted on the arrangement wall panel 320 via the quick-release mounting plate 330, and the traction drive motor 340 is fixed to the side of the corresponding quick-release mounting plate 330 away from the quick-release opening 321.

[0148] See Figure 7 The end of the traction roller 350 is mounted on the wall panel 320 via a guide drive mechanism 351. Further, see... Figure 6 To assist in the installation and positioning of the wall panel 320 and improve its installation stability, auxiliary positioning plates 324 are also provided on the wall panel 320 and the main support 1100. See also... Figure 7 The traction mechanism 300 also includes a limiting top block 322 to prevent the quick-release mounting plate 330 from detaching from the opening side of the quick-release opening 321. One or more fixing rods 360 are also provided between the wall panels 320 on both sides. Furthermore, at least two or more diagonally fixed fixing rods 360 are fixed, strengthening the structure while providing operational space. For a detailed description of the traction mechanism 300, please refer to CN223673945U.

[0149] See Figures 5-6The unwinding system 1000 further includes a winding tension adjustment mechanism 100, arranged on the main support 1100 and located between the release film peeling device 300A and the release film winding device 1300; including a proximity pressure roller 110 and an adjustment mechanism (shown in the figure but not labeled), wherein the proximity pressure roller 110 is disposed on the winding tension adjustment mechanism 100 and adjacent to the winding column 1300, and the adjustment mechanism is used to adaptively adjust the distance between the proximity pressure roller 110 and the outer surface of the winding column 1300 to control the tension of the release film 2100 during the winding process. Specifically, when the thickness of the winding column 1300 changes, the proximity pressure roller 110 is moved by the adjustment mechanism to precisely maintain a stable preset distance or preset distance range between the proximity pressure roller 110 and the outer surface of the winding column 1300 (when an allowable error exists, the preset distance range is the preset distance ± error distance), thereby controlling the tension of the release film 2100 on one side of the winding column 1300.

[0150] See Figures 5-6 as well as Figures 9-9 The adjustment mechanism includes a first drive mechanism 120 and a second drive mechanism 130. The first drive mechanism 120 drives the second drive mechanism 130 to approach or move away from the take-up column 1300 on the first drive mechanism 120. The end of the pressure roller 110 is mounted on the second drive mechanism 130, and the second drive mechanism 130 drives the pressure roller 110 to approach or move away from the take-up column 1300 on the second drive mechanism 130.

[0151] Understandably, the first drive mechanism 120 and the second drive mechanism 130 can be used individually or in combination to adaptively adjust the distance between the pressure roller 110 and the outer surface of the take-up column 1300 in order to adjust the corresponding lateral tension. Specifically, after the release film passes through the approach roller 110 to the winding column 1300, as winding begins, the thickness of the winding column 1300 increases. Since the approach roller 110 needs to adjust the winding angle and tension of the release film within a limited adjustment space, it must adaptively move away from the winding column 1300 while maintaining a stable preset distance. The second drive mechanism 130 moves the approach roller 110 outward. Simultaneously, if the second drive mechanism 130 cannot continue to drive the approach roller 110 closer to or further away from the winding column 1300, and the distance between the approach roller 110 and the outer surface of the winding column 1300 exceeds the preset distance, the first drive mechanism 120 can be executed again to move it closer to the winding column 1300 to correct this. Similarly, the second drive mechanism 130 can further drive the approach roller 110 when the first drive mechanism 120 can no longer drive it closer to or further away, and the first drive mechanism 120 can correct this again. As can be seen, by using the first drive mechanism 120 alone, or the second drive mechanism 130 alone, or both in combination, the driving in the same and / or opposite directions enables the proximity roller 110 to continuously maintain a preset distance from the winding column 1300 during operation, in order to adapt to the thickness changes of the winding column 1300, thereby achieving stable tension control. That is, the winding tension adjustment mechanism 100 of this application can adaptively adjust the distance between the proximity roller 110 and the winding column 1300, realizing the tension adjustment of the release film of the winding column 1300 within a limited length or space, thereby enabling the winding column 1300 to be wound smoothly and neatly, and the wound release film 2100 is tight, neat, and the rear end face is flat.

[0152] See Figures 5-6 as well as Figures 8-9 The first drive mechanism 120 and the second drive mechanism 130, which are close to the two sides of the pressure roller 110, are symmetrically arranged, which is more conducive to adjusting the tension of the roll release film 2100 during the unwinding process.

[0153] See Figure 8The first drive mechanism 120 includes a first power mechanism 121, a transfer base plate 122, and a first slide rail 123. A gear 124 is connected to the output end of the first power mechanism 121. The transfer base plate 122 is mounted on the first slide rail 123, and a rack 125 is fixed on the transfer base plate 122. The gear 124, in cooperation with the rack 125, drives the transfer base plate 122 to move on the first slide rail 123. Further, the first power mechanism 121 is a motor, such as a servo motor, to achieve high-precision single-drive intervals. Even further, the motor can steplessly adjust the gear 124, thereby cooperating with the rack 125 to achieve precise drive. Exemplarily, the rack 125 is fixedly mounted on the side of the transfer base plate 122, arranged along the length of the transfer base plate 122. Further, the rack 125 is detachably mounted on the side of the transfer base plate 122, that is, mounted on the side of the transfer base plate 122 closest to the first power mechanism 121.

[0154] Referring to 9, the second drive mechanism 130 includes a second power mechanism 131, a base slider 132, and a second slide rail 133. The second power mechanism 131 and the second slide rail 133 are both arranged on the transfer base plate 122. The second power mechanism 131 drives the base slider 132 to move on the second slide rail 133. The end near the pressure roller 110 is mounted on the base slider 132. The first power mechanism 121 drives the gear 124 to rotate, and then the gear 124 cooperates with the rack 125 on the transfer base plate 122 to drive the transfer base plate 122 to move on the first slide rail 123. At the same time, the second power mechanism 131 and the second slide rail 133 in the second drive mechanism 130 are both arranged on the transfer base plate 122, and the base slider 132 connected to the end near the pressure roller 110 is arranged on the second slide rail 133. That is, the entire second drive mechanism 130 is set on the transfer base plate 122. When the first power mechanism 121 drives the transfer base plate 122 to move, the second drive mechanism 130 on the transfer base plate 122 moves synchronously. That is, the first drive mechanism 120 can drive the second drive mechanism 130 to move, and drive the approach pressure roller 110 connected to the second drive mechanism 130; the second drive mechanism 130 on the transfer base plate 122 can also independently drive the approach pressure roller 110; thus, the first drive mechanism 120 and the second drive mechanism 130 can achieve relatively independent driving of the approach pressure roller 110, and the first drive mechanism 120 and the second drive mechanism 130 can cooperate to move in the same or opposite directions, realizing a complex adjustment process of the approach pressure roller 110. Further, the second power mechanism 131 is a cylinder. It can be understood that the cylinder can be a fixed stepping mode, and by controlling its airflow speed to match the roll material movement speed, the tension can be further adjusted and the winding effect improved.

[0155] See Figure 6 , Figures 8-9The winding tension adjustment mechanism 100 also includes a transfer roller 140 adjacent to the pressure roller 110. When the first drive mechanism 120 drives the second drive mechanism 130 to move, the transfer roller 140 is moved synchronously with the second drive mechanism 130, further improving the accuracy and effectiveness of tension adjustment, enabling the winding column 1300 to wind smoothly and neatly, resulting in a tight and neat release film after winding, and a flat rear end face. For example, see... Figure 6 , Figures 8-9 The transfer roller 140 is arranged in a direction away from the take-up column 1300, and the approach pressure roller 110 is located between the take-up column 1300 and the transfer roller 140. The end of the transfer roller 140 is fixedly connected to the first drive mechanism 120. Further, the end of the transfer roller 140 is mounted on the transfer base plate 122 near the side of the approach pressure roller 110 via the transfer roller bracket 141.

[0156] See Figure 6 , Figures 10-11The unwinding system 1000 also includes a floating roller device 400, which is mounted on the main support 1100 and located between the unwinding device 1200 and the release film peeling device 300A. The multilayer composite material 2000 is conveyed at least in the path sequence of the unwinding device 1200, the floating roller device 400 and the release film peeling device 300A. The floating roller device 400 is used to adjust the tension of the multilayer composite material 2000 during the conveying process. The floating roller device 400 includes a floating roller mounting main board 410, a floating roller body 420, a rotating shaft 430, a counterweight assembly 440, and a floating roller drive mechanism 450; the main support 1100 includes a base 1110 and main wall plates 1120 on both sides of the base 1110; the floating roller mounting main board 410 is rotatably mounted on the main wall plate 1120, the floating roller drive mechanism 450 drives the floating roller mounting main board 410 to rotate, the rotating shaft 430 passes through the floating roller main board and is mounted on the corresponding side main wall plate 1120, the rotating shaft 430 forms the rotation center of the floating roller mounting main board 410, the end of the floating roller body 420 is mounted on one side of the rotation center of the floating roller mounting main board 410, and the counterweight assembly 440 is set on the other side of the rotation center of the floating roller mounting main board 410. The floating roller drive mechanism 450 of this application drives the floating roller mounting main board 410 to rotate, thereby causing the floating roller body 420 to swing around the rotation center as the swing base point for corresponding tension adjustment. The counterweight assembly 440 is disposed on the opposite side of the floating roller body 420, which is beneficial for counterweight balance based on the self-weight of the floating roller body 420 and avoids the influence of the self-weight of the floating roller body 420 on accuracy. For example, the ratio D1:D2 of the distance between the rotation center and the floating roller body 420 and the distance between the rotation center and the counterweight assembly is (1.5~3):1. In addition, the swing angle range of the floating roller body 420 relative to the horizontal plane can optionally be -30°~30°. Further, the counterweight assembly 440 includes a counterweight rod 441 and weights 442 mounted on the counterweight rod 441. Furthermore, a counterweight rod 441 is mounted on the side of the floating roller mounting main plate 410 opposite to the floating roller body 420, and a weight 442 is detachably sleeved on the counterweight rod 441. Additionally, to ensure the adjustability of the floating roller's oscillation, a limit block 401 is provided on the main wall plate 1120 above and / or below the floating roller mounting main plate 410 to limit the oscillation range of the floating roller body 420. A detailed description of the floating roller device 400 can be found in CN223722348U.

[0157] See Figure 5 and Figure 12In addition to serving as a support, the main support 1100 can also function as a winding correction and conveying device. It includes a base 1110, a first winding correction mechanism 220, two main wall panels 1120, an upper base plate 1130, and a second winding correction mechanism 230. The first winding correction mechanism 220 is arranged above the base 1110, the main wall panels 1120 are arranged on the first winding correction mechanism 220, the upper base plate 1130 is arranged above the main wall panels 1120, and the second winding correction mechanism 230 is arranged on the upper base plate 1130. The unwinding column 1200 and the multi-layer composite material guide roller 1400 are installed between the two main wall panels 1120, and the winding column 1300 and the winding tension adjustment mechanism 100 are installed on the second winding correction mechanism 230. The first correction mechanism 220 is used at least to adjust the position of the unwinding column 1200 along its length, and the second correction mechanism 230 is used at least to adjust the position of the winding column 1300 along its length. Further, the first correction mechanism 220 includes a first guide assembly 221 and a lower base plate 222. The first guide assembly 221 is installed between the base 1110 and the lower base plate 222, and the main wall plate 1120 is installed on the lower base plate 222. The lower base plate 222 is driven to move the main wall plate 1120 relative to the base 1110 on the first guide assembly 221. Furthermore, the second correction mechanism 230 includes a second guide assembly 231 and a top plate 232, wherein the top plate 232 is located above the upper base plate 1130, the second guide assembly 231 is installed between the upper base plate 1130 and the top plate 232, and the winding column 1300 and the winding tension adjustment mechanism 100 are installed on the top plate 232; the top plate 232 is driven to move the winding column 1300 and the winding tension adjustment mechanism 100 relative to the upper base plate 1130 on the second guide assembly 231. Furthermore, the first guide assembly 221 is installed on the base 1110 via a pad. The lower base plate 222 cooperates with the first guide component 221 to form a guide sliding structure. When the lower base plate 222 is driven by an external force, it can move relative to the base 1110 along the guide direction of the first guide component 221 to correct the unwinding column 1200 above the inner lower base plate 222 to a suitable position. Similarly, the top plate 232 cooperates with the second guide component 231 to form a guide sliding structure. When the top plate 232 is driven by an external force, it can move relative to the upper base plate 1130 along the guide direction of the second guide component 231 to correct the unwinding column 1300 above the top plate 232 to a suitable position.

[0158] See Figure 12Multiple second guide components 231 are arrayed between the top plate 232 and the upper bottom plate 1130. Corresponding second guide components 231 are arranged on both the left and right sides, front and rear, improving guiding accuracy. Multiple positions restrict the guiding direction, overcoming guiding deviations caused by component errors; and enhancing its support for the upper structure (such as the winding device 1300), thus strengthening the overall structural stability. Furthermore, the top plate 232 has a U-shaped structure, with the winding column 1300 arranged on the opening side of the U-shaped structure of the top plate 232, which helps to fully utilize the remaining longitudinal space.

[0159] See Figure 12 The main support frame 1100 has upper base plates 1130 on both sides, and a support rod 202 is provided between the upper base plate 1130 and the lower base plate 222. The upper base plates 1130 on both sides are respectively installed above the main wall panels 1120 on both sides. The upper base plates 1130 are eccentrically positioned relative to the corresponding side wall panels. The lower part of the upper base plate 1130 on the side closer to the winding column 1300 is connected to the corresponding wall panel, and the lower part of the upper base plate 1130 on the side away from the winding column 1300 is connected to the upper end of the support rod 202. The lower base plate 222 extends to form a supporting part protruding from the wall panel, and the supporting part is connected to the lower end of the support rod 202. In addition, several reinforcing rods 203 are provided between the main wall panels 1120 to enhance the overall structural stability and ensure longitudinal support for the upper components. For a detailed description of the web-correcting conveyor device, please refer to CN223752085U.

[0160] See Figure 13This is a schematic diagram of the material feeding structure of an unwinding system 1000 with an integrated unwinding and take-up structure according to an embodiment of this application. Taking a multilayer composite material structure as a first release film 2100-1, a first adhesive layer, a polymer substrate layer 2200, a second adhesive layer, and a second release film 2100-2 as an example, in the first round of unwinding, the unwinding column 1200 unwinds the multilayer composite material 2000, which passes sequentially through the multilayer composite material guide roller 1400A, the floating roller device 400, and the peeling roller 1400B. After being peeled by the release film peeling device 300A, it is continuously pulled by the traction substrate 300, and the first release film 2100-1 separates from the surface of the multilayer composite material 2000 and is guided by the transfer roller 140. The material is wound from the upper side to the lower side of the pressure roller 110 and then to the winding column 1300. As the winding column 1300 winds up the first release film 2100-1, causing the thickness of the winding column 1300 to increase, the adjustment mechanism adjusts the position of the pressure roller 110 and / or the transfer roller 140 to control the tension of the first release film 2100 on the winding column 1300 side. The multilayer composite material, consisting of a first adhesive layer, a polymer substrate layer 2200, a second adhesive layer, and a second release film 2100-2, is guided to the composite system 2 by the peeling roller 1400B (optionally a third peeling roller 1400C) and the guide roller 21. In addition, during the unwinding process, the top plate 232 can be moved according to the actual correction requirements to perform the correction process on that side.

[0161] (2) Foil System 1:

[0162] Understandably, this application does not impose any special limitations on the foil-making system 1. For example, see [link to relevant documentation]. Figure 14 ,use Figure 1 The existing foil-making equipment shown is the foil-making system 1 of this application. Besides including a cathode roller 11 and an electrolytic cell 12, the foil-making system 1 further includes a foil peeling roller 13, a foil passivation device 14, and a foil winding device 15. The foil peeling roller 13 and the composite system 2 are arranged circumferentially along the cathode roller 11, with the foil peeling roller 13 located on one side of the cathode roller 11 and the composite pressure roller 23 located on the other side of the cathode roller 11. Furthermore, the foil passivation device 14 and the foil winding device 15 are located downstream of the foil peeling roller 13 and on the same side of the cathode roller 11. Further, it can be understood that when this application adopts… Figure 1 The existing foil production equipment shown is the foil production system 1 of this application. The foil production system 1 may further include a cleaning device 16 and a polishing device 17, wherein the cleaning device 16 and the foil stripping roller 13 are located on the same side of the cathode roller 11, and the cleaning device 16 is closer to the bottom of the cathode roller 11 than the foil stripping roller 13; the polishing device 17 and the composite pressure roller 23 are located on the same side of the cathode roller 11, and the polishing device 17 is closer to the bottom of the cathode roller 11 than the composite pressure roller 23.

[0163] Therefore, this application can directly use the existing foil-making equipment 1 as the foil-making system 1 in the composite foil production system F1 without modification. By changing the structure and / or position of the unwinding system 1000 and the composite system 2 and / or the roller conveying method (transfer route) of the composite foil intermediate, foil making and composite processing can be integrated. This allows for the production of both metal foil and composite foil, further reducing equipment costs and floor space. Specifically, on the one hand, the composite foil production system F1 of this application can produce metal foil independently using the existing foil-making equipment 1, and perform conventional passivation and winding processes according to the original method and transfer route, without being affected by the unwinding system 1000 and the composite system 2. On the other hand, the composite foil production system F1 of this application can also utilize the existing foil-making equipment 1 in conjunction with the unwinding system 1000 and the composite system 2 to produce composite foil, followed by passivation and winding processes, greatly reducing the equipment cost of the composite foil production system F1.

[0164] (3) Composite System 2:

[0165] See Figures 3-4 , Figures 14-15 as well as Figures 17-21 The composite system 2 includes a guide roller 21, a second tension roller 22, and a composite pressure roller 23. The guide roller 21 and the second tension roller 22 smoothly guide the multilayer composite material containing a polymer substrate layer 2200 onto the surface of the cathode roller 11. The composite pressure roller 23 abuts against the roller surface of the cathode roller 11, and composites the polymer substrate layer 2200, the adhesive layer, and the foil layer through roller pressing and adhesive action to obtain a composite foil. It is understood that this application does not impose any special limitations on the composite pressure roller 23; optionally, the composite pressure roller 23 can be a single roller or a combination of pressure rollers. For example, see [link to example]. Figures 3-4 , Figures 14-15 as well as Figures 17-21 Composite pressure roller 23 is a single roller.

[0166] Understandably, after preparing the composite foil (intermediate), it needs to be unwound and wound up. See also Figures 3-4 and Figures 14-15 The composite system 2 also includes a composite foil peeling roller 24, which is located beside the composite pressure roller 23 and is used to peel and pull the composite foil to the downstream for passivation and winding.

[0167] (4) Composite foil passing through roller 3:

[0168] See Figures 3-4 and Figures 14-15To ensure smooth and efficient transport of the composite foil, the composite foil production system F1 further includes several composite foil conveyor rollers 3, located downstream of the composite system 2, for transporting the composite foil intermediates (including single-sided composite foil intermediates-I 2500-1 and double-sided composite foil intermediates-I 2600-1) to the passivation system 4 and the winding system 5. Further, the number of composite foil conveyor rollers 3 is two or more, forming a composite foil conveyor roller assembly. Exemplarily, the composite foil intermediates are transported at least in the following path sequence: composite foil peeling roller 24, composite foil conveyor rollers 3, passivation system 4, and winding system 5.

[0169] (5) Passivation system 4:

[0170] Foil materials are prone to oxidation and discoloration. This application uses a passivation system 4 to prevent oxidation of the composite foil material during winding, transport, and use. See also Figures 3-4 and Figures 14-15 The passivation system 4 includes a composite foil passivation tank 41, a composite foil traction roller 42, a composite foil passivation roller 43, and a composite foil squeeze roller 44; wherein, the composite foil passivation tank 41 is used to hold the composite foil passivation liquid; the composite foil traction roller 42 is used to pull and control the composite foil intermediate into the composite foil passivation tank 41; the composite foil passivation roller 43 is used to transport or immerse the composite foil intermediate to be passivated in the composite foil passivation liquid; and the composite foil squeeze roller 44 is used to squeeze out the composite foil passivation liquid from the surface of the composite foil intermediate.

[0171] Furthermore, for some second adhesive layers that are not resistant to passivation solutions, the penetration of the passivation solution into the second adhesive layer may lead to a decrease in the adhesion of the second adhesive layer. During the second round of composite preparation of the double-sided composite foil intermediate - I2600-1, the polymer substrate layer 2200 and the second foil layer 2300-2 at the edge cannot be effectively laminated and need to be cut off, reducing utilization. To solve this problem, see [link to relevant documentation]. Figure 15 A first passivation device 45 containing a first passivation liquid can be added to the passivation system 4 to perform a first passivation treatment on the composite foil intermediate. During the first passivation treatment, one side of the composite foil intermediate acts as a liquid-coating layer in contact with the first passivation liquid. For the single-sided composite foil intermediate - I2500-1, the single-sided foil layer (such as the first foil layer 2300-1) also acts as an isolation layer, isolating the first passivation liquid from the second adhesive layer and the second release film 2100-2. In this way, the oxidation resistance of the single-sided foil layer can be improved, preventing the composite foil from oxidizing during winding or transport. It can also reduce the risk of the first passivation liquid penetrating into the second adhesive layer, providing a guarantee for the next step of bonding and laminating to prepare the double-sided foil intermediate - I 2600-1, avoiding lamination failure at the edge of the polymer substrate layer 2200 and the second foil layer 2300-2, and improving the utilization rate of the polymer substrate layer 2200 and the foil.

[0172] For example, the first passivation apparatus 45 includes a first coating mechanism for coating a first passivation liquid onto the single-sided foil layer. Furthermore, the first coating mechanism is selected from one or more combinations of a spray coating mechanism, a single-roller coating mechanism, a multi-roller coating mechanism, and a drop coating mechanism.

[0173] See Figure 16 In one embodiment of this application (A), a single-roller coating mechanism 4501 is provided, including: a first liquid receiving tray 45011 for holding a first passivation liquid; and a first liquid-coating roller 45012 disposed above the first liquid receiving tray 45011, the roller body being immersed in the first passivation liquid, and the first passivation liquid being coated onto a single-sided foil layer by rotation.

[0174] See Figure 16 In embodiment (B), this application provides a multi-roller coating mechanism 4502, including: a second liquid receiving tray 45021 for holding a first passivation liquid; a second liquid receiving roller 45022 disposed above the second liquid receiving tray 45021; and a third liquid receiving roller 45024 disposed on one side of the second liquid receiving roller 45022; the second liquid receiving roller 45022 is immersed in the first passivation liquid, and the first passivation liquid is coated onto the third liquid receiving roller 45024 by rotation and driving the roller to rotate, thereby coating the first passivation liquid onto a single-sided foil layer. Furthermore, in order to improve the uniformity of the coating, a third liquid-coating roller 45024 is disposed between a composite foil material passing roller 3 and a second liquid-coating roller 45022. The composite foil material passing roller 3 serves as a back roller and forms a pair of rollers with the third liquid-coating roller 45024. The composite foil intermediate body passes through the pair of rollers. The second liquid-coating roller 45022 is immersed in the first passivation liquid. By rotating, the first passivation liquid is coated onto the third liquid-coating roller 45024. The second liquid-coating roller 45022 and the composite foil material passing roller 3 jointly drive the third liquid-coating roller 45024 to rotate, coating the first passivation liquid onto one side of the foil layer.

[0175] See Figure 16 In the present application (C), one embodiment provides a drop-coating mechanism 4503, including: a dropper 45031 for applying a first passivation liquid in the form of droplets to a single-sided foil layer; and a uniform roller 45032 for uniformly coating droplets onto the single-sided foil layer.

[0176] Understandably, the first passivation device 45 may further include a drying device (not shown in the figure) for drying the composite foil intermediate after the first passivation treatment. Understandably, this application does not have special requirements for the drying device; optionally, the drying device includes one or more combinations of squeeze rollers, an oven, a blower, and a hot air knife.

[0177] Further, see Figure 15The combination of 41, 42, 43 and 44 in the passivation system 4 is used as the second passivation device 46. Along the transport direction of the composite foil intermediate, the first passivation device 45 is located upstream of the second passivation device 46. The second passivation device 46 is used for secondary passivation of the single-sided foil layer, and / or transport, and / or passivation of the double-sided foil layer.

[0178] (1) After the first round of foil production, unwinding and composite processes, the single-sided composite foil intermediate -I 2500-1 is transferred to the first passivation device 45. One side of its surface contains a second adhesive layer and a second release film 2100-2. The first passivation device 45 is used to passivate the first foil layer 2300-1, and the second passivation device 46 is used to transfer the composite foil intermediate. Optionally, this purpose can be achieved by setting the liquid level of the passivation liquid in the composite foil passivation tank 41 to be lower than the bottom roller surface of the composite foil passivation roller 43.

[0179] (2) Based on (1), after the first round of foil production, unwinding, composite, passivation and rewinding processes, a single-sided composite foil intermediate -2 is obtained. One side of the polymer substrate layer 2200 contains a first adhesive layer, a first foil layer 2300-1 and a support film 2400, and the other side contains a second adhesive layer and a second release film 2100-2. The first foil layer 2300-1 has undergone one or two passivation treatments. After the second round of foil production to form the second foil layer 2300-2, unwinding and composite processes, the composite foil intermediate transferred to the first passivation device 45 is a double-sided composite foil intermediate -I 2600-1, which can be passivated in either way ① or ②: ① The first passivation device 45 performs the first passivation treatment on the second foil layer 2300-2, and the second passivation device 46 is used for transfer. Alternatively, ② the first passivation device 45 performs preliminary passivation treatment on the second foil layer 2300-2, and the second passivation device 46 performs secondary passivation on the second foil layer 2300-2. Understandably, when the second passivation device 46 performs secondary passivation on the second foil layer 2300-2, it can also simultaneously perform secondary passivation on the first foil layer 2300-1 or simultaneously perform tertiary passivation on the first foil layer 2300-1. For example, method ② is used to passivate the double-sided composite foil intermediate, where the first passivation device 45 performs preliminary passivation treatment on the second foil layer 2300-2, and the second passivation device 46 performs secondary passivation on the second foil layer 2300-2, and simultaneously performs secondary passivation on the first foil layer 2300-1 or simultaneously performs tertiary passivation on the first foil layer 2300-1.

[0180] (6) Rewinding system 5:

[0181] See Figures 3-4 and Figures 14-15The winding system 5 of this application is located downstream of the composite system 2 and the passivation system 4. Besides the composite foil winding device 55, it also includes a support film unwinding device 52, a support film composite device 53, and a support film peeling and winding device 54. Before winding the single-sided composite foil intermediate -II 2500-2, the support film unwinding device 52 is used to unwind the support film 2400. The support film composite device 53 is used to cover the support film 2400 onto the foil surface (i.e., the first foil layer 2300-1) of the single-sided composite foil intermediate -I 2500-1. In the subsequent preparation of the double-sided composite foil, the support film 2400 not only improves the stability of film transport but also contacts the surface of the composite pressure roller 23 during the second round of lamination, preventing the extremely thin composite film from wrinkling or breaking, thus improving the lamination effect. The support film peeling and winding device 54 is used to peel and wind the double-sided composite foil intermediate -I before winding the finished double-sided composite foil 2600-2. The supporting film on the 2600-1 surface is 2400; the functional components work closely together to prepare a double-sided composite foil with excellent composite stability, mechanical properties and good appearance.

[0182] See Figures 3-4 and Figures 14-15 According to the transport direction of the polymer substrate layer 2200, the support film unwinding device 52 is located on the side of the polymer substrate layer 2200 close to the support film composite device 53. The unwound support film 2400 faces the foil surface of the single-sided composite foil intermediate - I 2500-1 (i.e., the first foil layer 2300-1) and enters the support film composite device 53 simultaneously with the single-sided composite foil intermediate - I 2500-1 for composite. The composite foil winding device 55 is located on the side of the polymer substrate layer 2200 away from the support film composite device 53. Along the direction away from the support film unwinding device 52, the support film peeling and winding device 54 is located beside the support film composite device 53 and upstream of the composite foil winding device 55. The second foil layer 2300-2 in the double-sided composite foil intermediate - I 2600-1 faces the support film composite device 53, and the support film 2400 faces the support film peeling and winding device 54.

[0183] The support film unwinding device 52 and the composite foil winding device 55 are respectively positioned upstream and downstream of the support film composite device 53. The support film unwinding device 52 and the support film peeling and winding device 54 are respectively positioned on opposite sides of the support film composite device 53, and the support film peeling and winding device 54 is also located upstream of the composite foil winding device 55. This achieves the following: the support film 2400 is applied to the foil surface of the single-sided composite foil intermediate - I 2500-1, and then the single-sided composite foil is wound up by the composite foil winding device 55. It also achieves the following: the support film 2400 is peeled off from the double-sided composite foil intermediate - I 2600-1, and then the double-sided composite foil is wound up by the composite foil winding device 55.

[0184] For example, see Figures 3-4 and Figures 14-15 The support film unwinding device 52 and the composite foil winding device 55 are respectively located on the upper and lower sides of the support film composite device 53, and the support film unwinding device 52 and the support film peeling and winding device 54 are respectively located on the left and right sides of the support film composite device 53, with both the support film composite device 53 and the support film peeling and winding device 54 located upstream of the composite foil winding device 55. Understandably, the directions "up," "down," "left," and "right" are based on... Figures 3-4 and Figures 14-15 As shown, this does not constitute a limitation on this application. For example, the support film unwinding device 52 and the composite foil winding device 55 may also be respectively disposed on the left and right sides of the support film composite device 53, and the support film peeling and winding device 54 and the support film unwinding device 52 may be respectively disposed on the upper and lower sides of the support film composite device 53, with both the support film composite device 53 and the support film peeling and winding device 54 located upstream of the composite foil winding device 55.

[0185] For example, see Figures 3-4 and Figures 14-15 The support film laminating device 53 includes a composite roller group that abuts against each other, and the support film 2400 is applied to the foil surface (i.e., the first foil layer 2300-1) of the single-sided composite foil intermediate - I 2500-1 by the roller pressing and laminating action; along the direction away from the support film laminating device 53, the support film peeling and winding device 54 includes a support film peeling roller 541 and a support film winding roller 542.

[0186] See Figure 3 The composite roller assembly includes a first composite roller 531 and a second composite roller 532. During the composite process of the support film 2400, the support film 2400 contacts the roller surface of the first composite roller 531, and the second release film 2100-2 contacts the roller surface of the second composite roller 532, so that the support film 2400 is applied to the foil surface (i.e., the first foil layer 2300-1) of the single-sided composite foil intermediate - I 2500-1.

[0187] Further, see Figure 4 The support film peeling roller 541 and the support film winding roller 542 are both located on one side of the second composite roller 532 and in a direction away from the second composite roller 532. The support film peeling roller 541 includes support film peeling roller No. 1 5411 and support film peeling roller No. 2 5412. During the support film peeling and winding process, the second foil layer 2300-2 contacts the roller surface of support film peeling roller No. 1 5411, and the support film 2400 contacts the roller surface of support film peeling roller No. 2 5412, so that the support film 2400 is peeled from the surface of the double-sided composite foil intermediate - I 2600-1 and transferred to the support film winding roller 542 for winding.

[0188] Furthermore, after a great deal of creative work, the inventors discovered that the composite foil transport path can be changed by adjusting the positions of the unwinding system 1000, the composite system 2, and the composite foil roller combination 3. This allows the existing foil production equipment 1 to be used as some functional components of the foil production system 1 and the winding system 5 of this application (such as the composite foil winding device 55). Only some functional rollers need to be added to the winding device 15 in the existing foil production equipment 1, without all changes / modifications. This greatly improves the utilization rate of the existing foil production equipment and greatly reduces the equipment cost.

[0189] For example, see Figures 17-21 This application may adopt Figure 1 The existing foil-making equipment 1 shown also serves as a functional component of both the foil-making system 1 and the winding system 5 of the composite foil production system F1, as described in detail below:

[0190] Known Figure 1 The foil production system 1 shown mainly includes an electrolytic cell 12, a cathode roller 11, a foil stripping roller 13, a foil passivation device 14, and a foil winding device 15 (understandably, for simplicity, the descriptions of the cleaning device 16 and the polishing device 17 are omitted here); wherein, the foil stripping roller 13 is located on one side of the cathode roller 11, and along the direction away from the cathode roller 11, the foil passivation device 14 and the foil winding device 15 are sequentially arranged on the same side of the foil stripping roller 13; the composite system 2 and the unwinding system 1000 are located on the cathode roller 11. On the other side, there are two or more composite foil rollers 3, forming a composite foil roller assembly, located on the periphery of the unwinding system 1000. The composite foil forms a U-shaped transmission path around the unwinding system 1000 on the composite foil roller assembly 3, with the U-shaped opening facing the foil winding device 15. The foil winding device 15 can be used as part of the functional components of the winding system 5 of this application, including: (1) the foil winding tension roller 1502 in the foil winding device 15 serves as the composite foil winding tension roller 51 for transmitting the composite foil intermediate. (2) the foil winding roller 1503 in the foil winding device 15 can serve as the first composite roller 531 in the support film composite device 53 and the support film peeling roller No. 1 5411 in the support film peeling and winding device 54; (3) the foil winding roller 1504 can serve as the composite foil winding device / composite foil winding roller 55.

[0191] See Figures 17-18Based on the functions of (1), (2), and (3) mentioned above, the foil winding device 15 can be further equipped with some functional rollers to work together as the winding system 5 of this application. For example, a support film unwinding roller can be added to the upper left of the existing foil winding roller 1503 as a support film unwinding device 52, and a second composite roller 532 in the support film composite device 53 can be added to the right side of the existing foil winding roller 1503 to form a support film composite device 53 (support film composite roller group). The support film 2400 unwound by the support film unwinding roller 52 and the single-sided composite foil intermediate -I 2500-1 enter the support film composite device 53 simultaneously, cover the support film 2400 on the first foil layer 2300-1, and then wind it up at the foil winding roller 1504.

[0192] Further, see Figures 17-18 The existing foil winding roller 1503 is used as the first support film peeling roller 5411. A second support film peeling roller 5412 is added to its lower right side, forming a support film peeling roller group 541 for peeling the support film 2400 in the double-sided composite foil intermediate body-I 2600-1. A support film winding roller 542 is added downstream to wind up the peeled support film 2400. The double-sided composite foil after peeling the support film is transferred to the foil winding roller 1504. That is, the support film peeling roller 541 and the support film winding roller 542 are both located on one side of the foil winding roller 1503 (the first composite roller 531 in the support film composite device 53). During the support film peeling and winding process, the second foil layer 2300-2 is in contact with the roller surface of the first composite roller 531, and the support film 2400 is in contact with the roller surface of the second support film peeling roller 5412.

[0193] As can be seen, the foil winding roller 1503 can function as both a support film laminating roller in the support film laminating device 53 before winding the single-sided composite foil intermediate -II 2500-2 and a support film peeling roller before winding the double-sided composite foil finished product 2600-2. The foil winding roller 1504, as the composite foil winding roller 55, can wind both single-sided and double-sided composite foil. Furthermore, adding these functional rollers does not affect the existing functions of the foil winding device 15. For example, when using the composite foil production system F1 of this application to produce metal foil, the foil winding device 15 winds the metal foil normally according to the original route.

[0194] Understandably, see Figure 17In the process of preparing single-sided composite foil (such as single-sided composite foil intermediate-II 2500-2), the support film 2400 is transported in the following order: support film unwinding device 52, support film composite device 53 and composite foil winding device 55. More specifically, the support film unwinding roller 52, foil winding roller 1503 (the first composite roller 531 in the support film composite device 53) and foil winding roller 1504 (composite foil winding roller 55) are transported in the following order, forming an S-shaped transport path.

[0195] Understandably, see Figure 18 In the process of preparing double-sided composite foil (such as double-sided composite foil finished product 2600-2), the support film 2400 is transported in the following path sequence: unwinding system 1000, composite system 2, composite foil roller 3 and support film peeling and winding device 54. More specifically, the path sequence is: unwinding device 1200, floating roller device 400, composite system 2, composite foil roller 3, foil winding roller 1503 (support film peeling roller No. 1 5411), support film peeling roller No. 2 5412 and support film winding roller 542.

[0196] Similarly, see Figures 17-18 By adjusting the positions of the unwinding system 1000, the composite system 2, and the composite foil roller assembly 3, the transport path of the composite foil is changed, thereby achieving the purpose of directly using the foil passivation device 14 in the existing foil production equipment 1 as the passivation system 4 of this application, which greatly reduces the equipment cost.

[0197] Furthermore, for the passivation system 4 that requires the provision of a first passivation device 45 and a second passivation device 46, please refer to... Figures 19-21 A first passivation device 45 is arranged on the U-shaped transport path of the composite foil (intermediate) to perform a first passivation treatment on one side of the foil layer in the composite foil intermediate (including single-sided composite foil intermediate-I 2500-1 and double-sided composite foil intermediate-I 2600-1). The foil passivation device 14 in the existing foil production equipment 1 is used as the second passivation device 46 in this application. Specifically, the foil passivation tank 1401 is used as the composite foil passivation tank 41, the first tension roller 1403 is used as the composite foil traction roller 42, the foil passivation liquid roller 1404 is used as the composite foil passivation roller 43, and the foil squeezing roller 1405 is used as the composite foil squeezing roller 44. Further, the foil drying box 1406 can be used as the drying box of the second passivation device 46 (not shown in the figure).

[0198] Understandably, this application places no particular limitations on the first passivation device 45. See also Figure 16 and Figure 19 The first passivation device 45 includes a single-roller coating mechanism 4501, which can be disposed between the first composite foil No. 1 roller 3101 and the first composite foil No. 2 roller 3102.

[0199] See Figure 16 and Figure 20 The first passivation device 45 includes a multi-roller coating mechanism 4502, which is located beside the first composite foil No. 2 passing roller 3102. The first composite foil No. 2 passing roller 3102 serves as a back roller and forms a pair of rollers with the third liquid-coating roller 45024. The single-sided composite foil intermediate body -I 2500-1 passes through the pair of rollers. The second liquid-coating roller 45022 is immersed in the first passivation liquid and coats the first passivation liquid onto the third liquid-coating roller 45024 by rotation. The first composite foil No. 2 passing roller 3102 and the second liquid-coating roller 45022 jointly drive the third liquid-coating roller 45024 to rotate, coating the first passivation liquid onto the first foil layer 2300-1.

[0200] See figure Figure 16 and Figure 20 The first passivation device 45 includes a drop coating mechanism 4503, which is located between the second composite foil No. 1 roller 3201 and the second composite foil No. 2 roller 3202, and is mounted above the unwinding system 1000.

[0201] As can be seen, the composite foil production system F1 of this application saves longitudinal space by using an unwinding system 1000 with an integrated unwinding and take-up structure to unwind multi-layer composite materials. Furthermore, the unwinding system 1000 and the composite system 2 are located on the same side of the cathode roller 11, while the take-up system 5 is located on the other side of the cathode roller 11. The composite foil intermediate is transported around the unwinding system 1000, passing over the cathode roller 11. This wrapping transport method (the composite foil intermediate forms a U-shaped transport path around the unwinding system 1000 on the composite foil roller assembly 3) can smoothly and effectively transport the composite foil intermediate to the post-processing side of the existing foil production equipment 1. The first passivation device 45 is arranged on the U-shaped conveying path to perform the first passivation treatment on one side of the foil layer of the composite foil intermediate. After the first passivation treatment, the composite foil intermediate is further conveyed to the foil passivation device 14 in the existing foil production equipment 1. The foil passivation device 14 is used as the second passivation device 46 of this application to convey or perform the second passivation treatment on the composite foil intermediate. Then it is further conveyed to the foil winding device 15 of the existing foil production equipment. With the addition of functional rollers, the composite foil (such as the intermediate) is processed and wound up. This makes full use of the longitudinal space, shortens the floor area of ​​the equipment / production line, and greatly reduces the equipment cost.

[0202] See Figures 17-21 The composite foil roller assembly 3 includes: a first composite foil roller assembly 31, located below the unwinding system 1000; and a second composite foil roller assembly 32, located above the unwinding system 1000; the composite foil is transported in the path sequence of the first composite foil roller assembly 31, the second composite foil roller assembly 32, and the winding system 5.

[0203] Understandably, in order to better flatten and control the tension during the composite foil transport process, the first composite foil roller assembly 31 includes at least two rollers. See also Figures 17-21 The first composite foil roller assembly 31 includes two rollers, which are sequentially configured as first composite foil No. 1 roller 3101 and first composite foil No. 2 roller 3102 in a direction away from the composite foil peeling roller 24. Further, it is known that... Figure 1 The foil production system 1 shown further includes a polishing device 17, which can be used directly without modification in this application. For example, the first composite foil roller assembly 31 is arranged above the polishing device 17 and below the unwinding system 1000.

[0204] Understandably, the second composite foil roll assembly 32 includes at least two rolls. See also Figures 17-21 The second composite foil guide roller assembly 32 includes two guide rollers, which are sequentially arranged as the second composite foil first guide roller 3201 and the second composite foil second guide roller 3202 in the direction close to the winding system 5 (such as the foil winding device 15). Furthermore, the second composite foil guide roller assembly 32 is located above the unwinding system 1000, specifically above the winding device 1300.

[0205] Understandably, the composite foil production system F1 also includes: a frame assembly (not shown in the figure), which has a multi-layer frame structure for mounting the unwinding system 1000, the first composite foil roller assembly 31, and the second composite foil roller assembly 32. The frame assembly is located beside the cathode roller 11 and the composite system 2, away from the winding system 5. The unwinding system 1000 is located on the upper layer of the frame assembly, the first composite foil roller assembly 31 is located on the lower layer of the frame assembly, and the second composite foil roller assembly 32 is located above the unwinding system 1000. The composite foil (intermediate material) is sequentially conveyed on the first composite foil roller assembly 31 and the second composite foil roller assembly 32, forming a U-shaped conveying path around the periphery of the unwinding system 1000, with the U-shaped opening facing the winding system 5. By setting up the frame assembly, the unwinding system 1000, the first composite foil roller assembly 31, and the composite foil roller assembly 32 (or further including the first passivation device 45) are further integrated into a three-dimensional layout, vertically integrating the process equipment, realizing the space optimization of the production line, and effectively reducing the requirement for lateral space while ensuring that the process flow remains unchanged.

[0206] Understandably, this application does not impose special restrictions on the material and installation method of the frame assembly, as long as it can support the unwinding system 1000 and install the composite foil conveyor roller assembly 3, achieving integrated unwinding and winding as well as the function of conveying the composite foil. In addition, for ease of operation, the frame assembly may also be equipped with guardrails and stairs, etc.

[0207] As can be seen from the above, the composite foil production system F1 of this application can either prepare foil separately, peel off the metal foil by the foil peeling roller 13, and then transfer it to the foil passivation device 14 of the existing foil production equipment for passivation and be wound up in the foil winding device 15; or prepare composite foil, peel it off from the surface of the cathode roller 11 by the composite foil peeling roller 24, then transfer it and perform the first passivation treatment through the wrapping conveying route of the composite foil passing roller combination 3, then transfer it to the foil passivation device 14 of the existing foil production equipment 1 for selective second passivation treatment, and then apply and peel off the support film 2400 in the foil winding device 15 with the help of the added functional roller, and then be wound up. In other words, the composite foil production system F1 of this application can not only realize the integration of foil production and composite production, but also directly use the existing foil production equipment 1 as the purpose of the foil production system 1, the second passivation device 46 and the winding system 5 of this application. The foil passivation device 14 in the existing foil production equipment 1 can passivate individual metal foils or transfer or passivate composite foils. The foil winding device 15 can wind up individual metal foils or wind up composite foils with the addition of functional rollers, which greatly improves the utilization rate of the existing foil production equipment and reduces the equipment cost and floor space of the composite foil production system.

[0208] Another objective of this application is to provide a composite current collector production system, including the composite foil production system F1 described above. Understandably, this composite current collector production system also possesses the advantages of the composite foil production system F1 described above, such as stable structure, low overall space occupancy, low equipment cost, ease of operation, convenient installation, layout and maintenance, and high utilization rate.

[0209] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0210] The embodiments described above are merely illustrative of several implementation methods of this application, intended to facilitate a detailed understanding of the technical solutions of this application, but should not be construed as limiting the scope of protection of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. It should be understood that technical solutions obtained by those skilled in the art based on the technical solutions provided in this application through logical analysis, reasoning, or limited experimentation are all within the scope of protection of the appended claims. Therefore, the scope of protection of this patent application should be determined by the content of the appended claims, and the specification and drawings can be used to interpret the content of the claims.

Claims

1. A method for preparing a composite foil, characterized in that, Includes the following steps: S100: Provide a composite substrate, the composite substrate comprising a first adhesive layer, a polymer substrate layer, a second adhesive layer and a second release film stacked sequentially; S200: The first foil layer is laminated to one side surface of the polymer substrate layer through the first adhesive layer to prepare a single-sided composite foil intermediate-I; S300: A support film is applied to the foil surface of the single-sided composite foil intermediate-I to prepare single-sided composite foil intermediate-II; S400: Peel off the second release film from the single-sided composite foil intermediate-II, and laminate the second foil layer to the other side of the polymer substrate layer through the second adhesive layer to prepare the double-sided composite foil intermediate-I; S500: Peel off the support film in the intermediate body-I of the double-sided composite foil to prepare a double-sided composite foil; Wherein, the bonding force between the support film and the first foil layer is F1, and the bonding force between the first adhesive layer and the first foil layer is F2, and F1 and F2 satisfy: F1 < F2.

2. The method for preparing the composite foil according to claim 1, characterized in that, The support membrane satisfies one or more of the following (1) to (4): (1) The thickness of the support membrane is 15μm~50μm; (2) F2 / F1 ≥ 2; (3) The tensile strength of the support membrane is 150MPa~350MPa, the elongation at break is 80%~400%, and the tensile strength corresponding to a constant elongation of 3% is ≥40MPa. (4) The material of the support membrane is one or more of the following: polyethylene terephthalate, polyethylene, polypropylene, polyimide, polyamide, polyester, polyvinyl chloride, polystyrene, polytetrafluoroethylene, polyvinylidene fluoride, polybutylene terephthalate, acrylonitrile-styrene copolymer, acrylonitrile-butadiene-styrene terpolymer, polyarylsulfone, polyethylene naphthalate, poly3,4-ethylenedioxythiophene, polyaniline and polypyrrole.

3. The method for preparing the composite foil according to claim 2, characterized in that, Satisfy one or more of the following (1)~(2): (1) F1 is 0.2N / 25mm~0.5N / 25mm; (2) F2≥0.6N / 25mm.

4. The method for preparing the composite foil according to any one of claims 1 to 3, characterized in that, Satisfy one or more of the following conditions (1) to (7): (1) The thickness of the polymer substrate layer is 1 μm to 6 μm; (2) The thicknesses of the first adhesive layer and the second adhesive layer are independently 0.2 μm to 4 μm; (3) The thicknesses of the first foil layer and the second foil layer are independently 0.8 μm to 3.5 μm; (4) The first foil layer and the second foil layer are each independently a combination of one or more of copper foil, aluminum foil, titanium foil, nickel foil, cadmium foil, iron foil and silver foil; (5) The polymer substrate layer is made of one or more of the following materials: polyethylene terephthalate, polyethylene, polypropylene, polyimide, polyamide, polyester, polyvinyl chloride, polystyrene, polytetrafluoroethylene, polyvinylidene fluoride, polybutylene terephthalate, acrylonitrile-styrene copolymer, acrylonitrile-butadiene-styrene terpolymer, polysulfone, polyethylene naphthalate, poly3,4-ethylenedioxythiophene, polyaniline and polypyrrole; (6) After step S200 and before step S300, the following steps are also included: The foil surface of the single-sided composite foil intermediate-I is brought into contact with the first passivation liquid for first passivation treatment; (7) After step S400 and before S500, the following steps are also included: The double-sided composite foil intermediate-I is brought into contact with a second passivation liquid for a second passivation treatment.

5. A composite foil production system for implementing the preparation method according to any one of claims 1 to 4, characterized in that, include: Unwinding system for unwinding multilayer composite materials; A foil production system, including a cathode roller, is used to produce at least a foil layer; A composite system, including a composite roller, is used to composite a polymer substrate layer, an adhesive layer, and a foil layer to obtain a composite foil. A winding system, located downstream of the composite system, includes a support film unwinding device, a support film laminating device, a support film peeling and winding device, and a composite foil winding device; wherein, the support film unwinding device is used to unwind the support film, the support film laminating device is used to cover the support film onto the foil surface of the single-sided composite foil intermediate-I, the support film peeling and winding device is used to peel off and wind up the support film on the surface of the double-sided composite foil intermediate-I, and the composite foil winding device is used to wind up at least the single-sided composite foil intermediate-II and the double-sided composite foil; In the process of preparing single-sided composite foil intermediate-I, the second release film is in contact with the surface of the composite pressure roller; the polymer substrate layer is transferred in the following path sequence: unwinding system, composite system, support film composite device and composite foil winding device; In the process of preparing double-sided composite foil intermediate-I, before single-sided composite foil intermediate-II enters the composite system, the second release film on the surface is peeled off, and the support film contacts the surface of the composite pressure roller; the polymer substrate layer is transferred in the following path sequence: unwinding system, composite system, support film peeling and winding device, and composite foil winding device.

6. The composite foil production system according to claim 5, characterized in that, According to the transport direction of the polymer substrate layer, the support film unwinding device is located on the side of the polymer substrate layer closer to the support film composite device; the composite foil winding device is located on the side of the polymer substrate layer away from the support film composite device. Along a direction away from the support film unwinding device, the support film peeling and winding device is located beside the support film composite device and upstream of the composite foil winding device; the second foil layer in the double-sided composite foil intermediate-I faces the support film composite device, and the support film faces the support film peeling and winding device.

7. The composite foil production system according to claim 6, characterized in that, The support film laminating device includes a first composite roller and a second composite roller that abut against each other, forming a composite roller group; during the support film laminating process, the support film is in contact with the roller surface of the first composite roller, and the second release film is in contact with the roller surface of the second composite roller, and the support film is applied to the foil surface of the single-sided composite foil intermediate-I through the roller pressing laminating action; The support film peeling and winding device includes a support film peeling roller and a support film winding roller, both located beside the composite roller group.

8. The composite foil production system according to claim 7, characterized in that, Both the support film peeling roller and the support film winding roller are located on one side of the first composite roller. During the support film peeling and winding process, the second foil layer contacts the roller surface of the first composite roller, and the support film contacts the roller surface of the peeling roller, so that the support film is peeled from the surface of the double-sided composite foil intermediate - I and transferred to the support film winding roller for winding.

9. The composite foil production system according to any one of claims 5 to 8, characterized in that, Satisfy one or more of the following conditions (1) to (7): (1) The foil system further includes an electrolytic cell for containing an electrolyte, wherein the bottom of the cathode roller is immersed in the electrolyte to form the foil layer on the surface of the cathode roller; (2) The foil system further includes a cleaning device for cleaning the foil layer on the surface of the cathode roller. The cleaning device and the composite pressure roller are arranged along the circumference of the cathode roller and are located on both sides of the cathode roller, respectively. (3) The foil production system further includes a foil stripping roller for stripping the foil layer on the surface of the cathode roller. The foil stripping roller and the composite pressure roller are arranged along the circumference of the cathode roller and are located on both sides of the cathode roller, respectively. (4) The foil system further includes a foil passivation device, which is located on the same side of the cathode roller as the foil stripping roller, and is used at least to passivate the foil stripped from the surface of the cathode roller; (5) The foil system further includes a foil winding device, which is located on the same side of the cathode roller as the foil stripping roller, and is used at least to wind up the foil stripped from the surface of the cathode roller; (6) The foil system further includes a polishing device for polishing the surface of the cathode roller. The polishing device is arranged opposite to the cathode roller, located on the same side of the composite pressure roller, and closer to the bottom of the cathode roller. (7) The composite foil production system also includes a passivation system, located downstream of the composite system and upstream of the winding system, for at least passivating the composite foil.

10. The composite foil production system according to claim 9, characterized in that, The unwinding system includes an unwinding device, a release film peeling device, and a release film winding device; wherein, the unwinding device is used to unwind the multilayer composite material, the peeling device is used to peel off the release film and transfer it to the release film winding device for winding, and to transfer the polymer substrate layer and its surface adhesive layer to the downstream for lamination.

11. The composite foil production system according to claim 10, characterized in that, It also includes two or more composite foil conveyor rollers to form a composite foil conveyor roller assembly for conveying composite foil; the composite system and the unwinding system are located on the same side of the cathode roller, the winding system is located on the other side of the cathode roller, the composite foil conveyor roller assembly is located on the periphery of the unwinding system, and the composite foil forms a U-shaped conveying path around the unwinding system on the composite foil conveyor roller assembly, with the U-shaped opening facing the winding system.

12. A composite current collector production system, characterized in that, The composite foil production system includes any one of claims 5 to 12.

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