Composite foil apparatus and composite current collector production system

Abstract

The application relates to a composite foil device and a composite current collector production system. The composite foil device comprises a gradient heating device for gradient heating of a base material and a glue layer arranged on at least one side surface of the base material, wherein the temperature gradient increases along the transmission direction of the base material; a foil generating device downstream of the gradient heating device, which is used for generating at least a foil layer; and a composite device for compounding the base material and the foil layer to obtain a composite foil. The composite foil device improves the adhesion of the glue layer by gradient heating of the base material and the glue layer before compounding, so that the base material and the metal foil are firmly bonded together, the peelability of the foil layer is improved, the uniformity, structural stability and mechanical properties of the composite foil are improved, the base material is prevented from being deformed by heat, or the glue layer is prevented from being excessively shrunk, the wrinkles and edge warping of the composite foil are reduced, and the production cost of the composite foil is reduced.

Description

Technical Field

[0001] This application relates to the field of multilayer composite material technology, and more specifically, to a composite foil device and a composite current collector production system thereof. 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 has problems such as high production costs, high density, large weight ratio, and low battery safety and energy density. In order to reduce the use of metal, effectively reduce the cost of battery current collectors, and improve the overall energy density and safety of batteries, the industry has developed a current collector composed of a polymer substrate layer and a metal foil layer disposed on one or both sides of the polymer substrate layer, called a composite current collector.

[0003] Taking composite copper foil as an example, traditional composite copper foil is usually made by "one-step," "two-step," and "three-step" copper plating processes. The one-step process uses chemical deposition or magnetron sputtering in a single step. The two-step process first deposits 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 electroplating to accelerate metal layer deposition. Regardless of whether it's a one-step, two-step, or three-step process, all suffer from complex and uncontrollable processes, poor uniformity of the composite copper foil, high equipment costs, high production costs, and difficulty in mass production. Furthermore, methods have been reported that first composite thick copper foil with polymers using roll pressing or hot pressing, and then thinning to the required thickness using chemical wire reduction or mechanical processing, also suffer from complex and uncontrollable processes, resulting in poor performance of the composite copper foil.

[0004] Therefore, the industry urgently needs to develop a new composite foil processing device that can simplify the production process, reduce equipment costs, and ensure the performance of the composite foil. Utility Model Content

[0005] Based on this, this application provides a composite foil device that can simplify the production process, reduce costs, and ensure the performance of the composite foil.

[0006] The technical solution adopted in this application is a composite foil device, comprising:

[0007] A gradient heating device is used to gradient heat a substrate and an adhesive layer disposed on at least one side surface of the substrate, wherein the temperature gradient increases along the transport direction of the substrate;

[0008] A foil-forming apparatus, for at least forming a foil layer, is located downstream of the gradient heating apparatus along the transport direction of the substrate; and

[0009] A composite device for bonding the substrate and the foil layer to obtain the composite foil.

[0010] In one embodiment, after gradient heating, the temperature of the substrate and the adhesive layer is T1, and the heat distortion temperature of the substrate is T2, wherein T1 and T2 satisfy: T1 < T2.

[0011] In one embodiment, the gradient heating curve is one or more combinations of linear temperature gradient, nonlinear temperature gradient, and step temperature gradient.

[0012] In one embodiment, the gradient heating device includes:

[0013] A heating chamber defining a channel for the substrate and adhesive layer to pass through and for heat treatment; and,

[0014] Multiple heating units are arranged sequentially along the transmission direction of the substrate and each maintains a different set temperature, thereby forming a continuous or stepped temperature gradient field to gradually increase the temperature of the substrate and the adhesive layer.

[0015] In one embodiment, each of the heating units independently includes: a heating element, a temperature sensor, an independent temperature control module, and a control system;

[0016] The independent temperature control module is electrically connected to the heating element and the temperature sensor; the control system is communicatively connected to each independent temperature control module and is configured as follows:

[0017] (1) Receive temperature signals from each of the temperature sensors;

[0018] (2) Based on the preset temperature gradient curve or the target temperature value of each heating unit, send control commands to the corresponding temperature control module;

[0019] (3) Each of the heating units is controlled to maintain a different set temperature in the channel along the transmission direction of the substrate, thereby forming a continuous or stepped temperature gradient field.

[0020] In one embodiment, each of the heating elements is independently selected from one or more combinations of resistance heating elements, infrared heating elements, electromagnetic induction elements, microwave generators, and PTC ceramic heaters;

[0021] In one embodiment, each temperature sensor is independently selected from one or more combinations of thermocouple type, resistance temperature detector (RTD) type, infrared temperature sensor, semiconductor type, and fiber optic type temperature sensors.

[0022] In one embodiment, the composite foil apparatus further includes a gradient cooling device located downstream of the composite apparatus for gradient cooling of the composite foil.

[0023] In one embodiment, the gradient cooling device includes:

[0024] A cooling substrate having a cooling surface for contacting a composite foil; the cooling substrate having a plurality of independent fluid channels spaced along the transport direction of the composite foil; and

[0025] Multiple independent refrigerant circulation loops.

[0026] In one embodiment, the foil-forming apparatus includes a tank containing an electrolyte and a rotatable cathode roller, a portion of which is immersed in the electrolyte to form the foil layer on the surface of the cathode roller.

[0027] In one embodiment, the composite device includes a pressure roller assembly and a guide roller; the pressure roller assembly is configured with the cathode roller surface as follows: with the cathode roller surface as a support surface, the pressure roller assembly is arranged at intervals along the circumference of the cathode roller, and the pressure roller assembly presses down on the substrate and the foil layer to obtain the composite foil; the guide roller is used to pull the composite foil away from the cathode roller surface.

[0028] In one embodiment, the composite foil apparatus further includes an unwinding device and a winding device; the unwinding device is used at least to unwind the substrate; the winding device is used at least to wind the composite foil; after the substrate is unwound from the unwinding device, it passes sequentially through the gradient heating device and the composite device, and is composited with the foil layer to form the composite foil, which is then wound up by the winding device.

[0029] In one embodiment, the composite foil apparatus further includes an adhesive coating device for coating an adhesive layer on the surface of a substrate.

[0030] In one embodiment, the composite foil apparatus further includes a substrate surface treatment device located downstream of the unwinding device and upstream of the coating device, for performing surface treatment on the substrate.

[0031] In one embodiment, the composite foil apparatus further includes a passivation treatment device located downstream of the composite apparatus and upstream of the winding device, for passivating the composite foil.

[0032] In one embodiment, the substrate comprises one or more of 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.

[0033] In one embodiment, the adhesive layer comprises one or more combinations of rosin resin, terpene resin, petroleum resin, polyurethane resin, polyacrylic resin, epoxy resin, phenolic resin, polyester resin, polyimide, silicone polymer and its modified compounds, and polyolefin and its modified compounds.

[0034] In one embodiment, the foil layer comprises one or more combinations of copper foil and aluminum foil.

[0035] Another object of this application is to provide a composite current collector production system, including the composite foil device as described above.

[0036] This application has at least the following beneficial effects:

[0037] Compared to methods such as magnetron sputtering or electroplating on a substrate surface to form composite copper foil, or preparing a composite copper foil containing a thick copper layer and then thinning the thick copper layer, this application utilizes the adhesive properties of the adhesive layer to directly composite the metal foil (such as copper foil) prepared by the foil-making device with the substrate to form a composite foil material. The foil layer is uniformly bonded to the surface of the substrate, resulting in high composite strength and structural stability between the substrate and the foil. Furthermore, the composite process is simpler and faster, requiring no complex or expensive production equipment, facilitating mass production and overcoming the difficulty in mass-producing composite foil materials, especially composite copper foil. In addition, the metal foil does not require separate peeling, winding, transportation, and storage steps, improving production efficiency, reducing losses, and further lowering production costs.

[0038] Furthermore, the surface temperature of the metal foil produced by the foil-making equipment is typically 40℃~55℃. Heating the substrate and adhesive layer before lamination can reduce the surface temperature difference between the substrate, adhesive layer, and metal foil during the lamination stage, improve the adhesive layer's adhesion, and enhance the bonding strength between the substrate and metal foil. If the pressure roller or lamination roller is directly heated, the lamination process is rapid due to the close distance between adjacent pressure rollers, resulting in a large surface temperature difference between the substrate, adhesive layer, and metal foil, leading to poor lamination results. This application addresses this by gradient heating of the substrate and adhesive layer before lamination, gradually increasing their temperatures, improving the adhesive layer's adhesion, and ensuring a firm bond between the substrate and metal foil. This improves the foil's peelability and enhances the uniformity, structural stability, and mechanical properties of the composite foil. It also prevents heat deformation of the substrate or excessive shrinkage of the adhesive layer, reducing wrinkles and edge warping in the composite foil. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the structure of a composite foil device according to an embodiment of this application;

[0040] Figure 2 This is a schematic diagram of the gradient heating device according to an embodiment of this application;

[0041] Figure 3 This is a schematic diagram of the structure of a composite foil device according to an embodiment of this application;

[0042] Figure 4 This is a schematic diagram of the structure of a composite foil device according to an embodiment of this application;

[0043] Figure 5 This is a schematic diagram of the structure of a composite foil device according to an embodiment of this application;

[0044] Figure 6 This is a schematic diagram of the structure of a composite foil device according to an embodiment of this application;

[0045] Figure 7 This is a schematic diagram of the structure of a composite foil device according to an embodiment of this application;

[0046] Figure 8 This is a schematic diagram of the structure of a composite foil device according to an embodiment of this application;

[0047] Figure 9 This is a schematic diagram of the structure of a composite foil device according to an embodiment of this application;

[0048] Figure 10 This is a schematic diagram of the structure of a composite foil device according to an embodiment of this application;

[0049] Figure 11 This is a schematic diagram of the composite copper foil device shown in proportion to a pair of figures in this application;

[0050] Figure 12 This is a schematic diagram of the composite copper foil device shown in proportion to a pair of figures in this application;

[0051] Figure 13 This is a schematic diagram of the composite copper foil device shown in proportion to a pair of figures in this application;

[0052] Explanation of reference numerals in the accompanying drawings: The composite foil device 10, gradient heating device 101, heating cavity 1011, heating unit 1012, foil production device 102, electrolytic cell 1021, cathode roller 1022, composite device 103, pressure roller assembly 1031, guide roller 1032, unwinding device 104, winding device 105, gradient cooling device 106, adhesive coating device 107, substrate surface treatment device 108, passivation treatment device 109, first comparative composite copper foil device 11, second comparative composite copper foil device 12, heating device 110, hot pressing composite device 120, hot pressing composite roller 1201, peeling roller 1202, and third comparative composite copper foil device 13. Detailed Implementation

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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, "at least one" refers to one or more, including one, two, or more than two, and "multiple" refers to two or more, including two, three, or more than three, unless otherwise explicitly specified.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] See Figure 1 One embodiment of this application provides a composite foil device 10, comprising:

[0062] The gradient heating device 101 is used to gradient heat the substrate and the adhesive layer disposed on at least one side surface of the substrate, with the temperature gradient increasing along the transport direction of the substrate.

[0063] A foil-forming device 102, used for at least forming a foil layer, is located downstream of the gradient heating device 101 along the substrate transport direction; and

[0064] The composite device 103 is used to composite a substrate and a foil layer to obtain a composite foil.

[0065] The surface temperature of the metal foil prepared by the foil-making apparatus 102 is typically 40°C to 55°C. Heating the substrate and adhesive layer before lamination can reduce the surface temperature difference between the substrate, adhesive layer, and metal foil during the lamination stage, thereby improving the lamination effect. Furthermore, adhesive molecules diffuse towards the surface of the adhered objects via Brownian motion, causing the polar groups or chain segments at the interfaces to approach each other. This application, by gradient heating of the substrate and adhesive layer before lamination, gradually increases the temperature of the substrate and adhesive layer, improving the adhesive strength of the adhesive layer, ensuring a firm bond between the substrate and the metal foil, improving the peelability of the foil layer, and enhancing the uniformity, structural stability, and mechanical properties of the composite foil. It also prevents thermal deformation of the substrate or excessive shrinkage of the adhesive layer, reducing wrinkles and edge warping in the composite foil.

[0066] Understandably, this application does not impose any special limitations on the substrate. Optionally, the substrate 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 substrate is PET or PP.

[0067] Understandably, this application does not impose any special limitations on the adhesive layer. Optionally, the adhesive layer includes 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. Among these, the main component of rosin resin is resin acid, accounting for more than 90% of its total content, in addition to small amounts of fatty acids and neutral substances. Terpene resin is a polymer formed by the polymerization of α-pinene or β-pinene. Petroleum resins can be broadly classified into five categories: C5 aliphatic petroleum resins, C9 aromatic petroleum resins, C5-C9 copolymer petroleum resins, dicyclopentadiene (DCPD) alicyclic petroleum resins, and hydrogenated modified petroleum resins.

[0068] Understandably, this application does not impose any special limitations on the foil layer. Optionally, the foil layer includes one or more combinations of copper foil and aluminum foil. Exemplarily, the foil layer is copper foil.

[0069] In order to further improve the adhesion of the adhesive layer, make the substrate and the metal foil bond together more firmly, reduce the deformation of the substrate, and improve the uniformity and mechanical properties of the composite foil, this application specifies that after gradient heating, the temperature of the substrate and the adhesive layer is T1, and the heat distortion temperature of the substrate is T2, wherein T1 and T2 satisfy: T1 < T2.

[0070] Understandably, this application does not impose any special limitations on the gradient heating curve, as long as it achieves the purpose of gradient heating. For example, the gradient heating curve includes, but is not limited to, one or more combinations of linear temperature gradients, nonlinear temperature gradients, and step-type temperature gradients. Further, a linear temperature gradient curve refers to a temperature change that occurs at a fixed ratio as the substrate and adhesive layer move along the transmission direction of the gradient heating device 101, as described in a linear equation, where the rate of temperature change (slope) is constant. A nonlinear temperature gradient curve refers to a temperature change that occurs at a non-constant rate as the substrate and adhesive layer move along the transmission direction of the gradient heating device 101, as described in exponential, logarithmic, or parabolic functions. A step-type temperature gradient curve refers to a temperature change that occurs at a non-constant rate over time; by controlling the moving speed (linear speed) of the gradient heating device 101 and the substrate and adhesive layer, the substrate and adhesive layer will experience multiple rapid heating stages and constant temperature holding stages during the movement.

[0071] Understandably, this application does not impose any special restrictions on the structure of the gradient heating device 101, as long as it can achieve the purpose of gradient heating of the substrate and the adhesive layer. Optionally, the gradient heating device 101 can be a structure of independent heating units in series, a segmented integral heating body structure, a heat conduction gradient structure, or a moving heating source structure.

[0072] See Figure 2 The gradient heating device 101 provided in one embodiment of this application includes:

[0073] Heating chamber 1011, the heating chamber 1011 defines a channel for the substrate and adhesive layer to pass through and for heat treatment; and,

[0074] Multiple heating units 1012 are arranged sequentially along the transport direction of the substrate and each maintains a different set temperature, thereby forming a continuous or stepped temperature gradient field to gradually heat the substrate and adhesive layer.

[0075] In one embodiment, each heating unit 1012 independently includes: a heating element, a temperature sensor, an independent temperature control module, and a control system;

[0076] The independent temperature control module is electrically connected to the heating element and temperature sensor; the control system is communicatively connected to each independent temperature control module and configured as follows:

[0077] (1) Receive temperature signals from each temperature sensor;

[0078] (2) Based on the preset temperature gradient curve or the target temperature value of each heating unit 1012, send control commands to the corresponding temperature control module;

[0079] (3) Each heating unit 1012 is controlled to maintain a different set temperature in the channel along the transmission direction of the substrate, thereby forming a continuous or stepped temperature gradient field.

[0080] Understandably, this application does not impose any special limitations on the heating element, as long as it can achieve the purpose of heating the substrate and the adhesive layer. Optionally, each heating element may be independently selected from one or more combinations of resistance heating elements, infrared heating elements, electromagnetic induction elements, microwave generators, and PTC ceramic heaters.

[0081] Understandably, this application does not impose any special restrictions on the temperature sensor, as long as it can achieve the purpose of temperature sensing. Optionally, each temperature sensor may be independently selected from one or more combinations of thermocouple type, resistance temperature detector (RTD) type, infrared temperature measurement, semiconductor type, and fiber optic type temperature sensors.

[0082] See Figure 1 , Figures 3-10 The foil-forming apparatus 102 provided in one embodiment of this application includes a tank (referred to as an electrolytic tank 1021) for containing electrolyte and a rotatable cathode roller 1022. A portion of the cathode roller 1022 can be immersed in the electrolyte to form a foil layer on the surface of the cathode roller 1022. Further, the foil-forming apparatus 102 is installed underground, and a drive motor is connected to the end of the cathode roller 1022. The cathode roller 1022 is driven to rotate by the drive motor connected to the end; and a conductive copper ring is also provided on the transmission shaft connecting the cathode roller 1022 and the drive motor.

[0083] See Figure 1 , Figures 3-10 The composite device 103 provided in one embodiment of this application includes a pressure roller assembly 1031 and a guide roller 1032; the pressure roller assembly 1031 and the cathode roller 1022 are configured such that the surface of the cathode roller 1022 serves as the support surface, the pressure roller assembly 1031 is arranged at intervals along the circumference of the cathode roller 1022, and the pressure roller assembly 1031 presses down the substrate and foil to obtain a composite foil; the guide roller 1032 is used to pull the composite foil away from the surface of the cathode roller 1022.

[0084] Furthermore, the pressure roller assembly 1031 is formed by two or more pressure roller assemblies, each pressure roller assembly including a pressure roller and a telescopic mechanism connecting the pressure rollers; the pressure roller assembly 1031 is at least used for driving the substrate and adhesive layer, and pressing down the substrate and foil layer to obtain the composite material, and at least one pressure roller assembly in the pressure roller assembly 1031 is arranged circumferentially along the foil production device 102.

[0085] For example, in the pressure roller assembly 1031, the pressure roller near the upstream end (gradient heating device 101) is the preliminary pressing roller, and the pressure roller near the downstream end is the finishing pressing roller; the pressure roller assembly in the pressure roller assembly 1031 is configured such that the pressing pressure F1 of the preliminary pressing roller is greater than the pressing pressure F2 of the finishing pressing roller. When the composite materials reach the initial pressing roller for lamination, the initial pressing roller provides strong pressing pressure, thus tightly pressing the composite layer in the initial bonding state and maintaining sufficient stretch of the composite material in the pressing area. It also squeezes out any gaps or air bubbles that may exist at the composite interface towards the upstream input side, ensuring that the composite interface of the composite layer after passing through the initial pressing roller is completely bonded and basically free of obvious air bubbles and gaps, thereby improving the lamination quality. The final pressing roller provides a pressing pressure of F2, which is less than F1. This avoids excessive stretching caused by strong tension on both the front and back sides of the composite layer, and avoids wrinkles caused by elastic contraction after passing through the pressing area. At the same time, it avoids the continuous accumulation of obvious air gaps, because the composite layer after passing through the initial pressing roller may still have a very small number of air gaps that have little impact on the performance of the composite layer. If the final pressing roller also maintains strong pressing pressure, it may squeeze air gaps upstream, that is, between the initial pressing roller and the final pressing roller. As the production process progresses, this will continue to accumulate in multiple areas of the finished composite layer, forming obvious air bubbles or wrinkles, which will significantly affect the quality of the final product. On the other hand, setting F2 < F1 also facilitates the export and separation of the composite layer. The reduced pressure of the tail pressing roller compared to the upstream pressing roller helps alleviate the adhesion of the wound material to the corresponding supporting roller, making it easier for the composite wound material to detach from the corresponding roller along the transmission direction. If F2 is a strong pressing pressure, the wound material may easily stick to the corresponding supporting roller as the material travels, and uneven force during the export of the composite layer can easily cause tearing. The downward pressure includes the pressure exerted perpendicularly by the corresponding pressure roller on the surface of the supporting roller.

[0086] To improve the composite effect of the substrate and metal foil layer, and to enhance the uniformity and mechanical properties of the composite foil, such as... Figure 1 , Figures 3-10As shown, the pressure roller combination 1031 comprises more than three pressure roller assemblies. Specifically, the pressure roller combination 1031 includes a preliminary pressing roller, a finishing pressing roller, and one or more transition pressing rollers located between the preliminary pressing roller and the finishing pressing roller; in the pressure roller combination 1031, the pressure roller assemblies are configured such that the downward pressing pressure F1 of the preliminary pressing roller is greater than the downward pressing pressure F2 of the finishing pressing roller, and the downward pressing pressure F1 of the preliminary pressing roller is greater than the downward pressing pressure F3 of the transition pressing roller. Further, F3≥F2. Still further, in the pressure roller combination 1031, the pressure roller assemblies are configured such that F1>F3>F2, and the downward pressing pressure decreases progressively in the direction from preliminary pressing to finishing pressing, with the decreasing ratio ranging from 3% to 20%; that is, F1×3% < F1-F3 < F1×20%, and F3×3% < F3-F2 < F3×20%. Still further, the decreasing ratio ranges from 5% to 15%, F1×5% < F1-F3 < F1×15%, and F3×5% < F3-F2 < F3×15%. Further, the values of F1, F2 and F3 are within the range of 0.1N / in to 10N / in (0.1N per inch to 10N per inch). Further, the diameter of the pressure rollers in the pressure roller combination 1031 ranges from 120mm to 200mm.

[0087] The preliminary pressing roller adopts a relatively large pressing pressure in the initial stage of lamination, so that the downward pressing area is stressed centrally to achieve sufficient pressing and prevent air bubbles from entering. The finishing pressing roller assists in pressing the composite layer to enhance the bonding strength, and besides extending the pressing area of the composite layer during travel, the finishing pressing roller can also slowly release the composite layer, thereby prompting the composite layer to detach from the abutting roller body and be guided out. The transition pressing roller can at least also play the auxiliary pressing role of the finishing pressing roller, preferably its downward pressing pressure F3 is also smaller than F1, and as an intermediate transition pressing roller, it can increase the auxiliary pressing area and further improve the lamination effect. Combined with the condition that F3 is smaller than F1, progressive slowing of pressing and releasing can be realized in cooperation with the preliminary pressing roller and the finishing pressing roller. It provides more diverse adjustment processes, which is convenient for selective adjustment in accordance with material characteristics and lamination requirements.

[0088] In order to improve the lamination effect of the base material and metal foil and improve the uniformity and mechanical properties of the laminated foil, the present application defines that the surface hardness H1 of the preliminary pressing roller is greater than the surface hardness H2 of the finishing pressing roller; the surface hardness H1 of the preliminary pressing roller is greater than the surface hardness H3 of the transition pressing roller. Further, H3≥H2; further, the roller surface hardness includes the rubber hardness of the roller body surface, which is Shore A hardness, and H1≥45 degrees; still further, H1>H3>H2. And H1 ranges from 45 to 55 degrees; H3 ranges from 35 to 45 degrees; H2 ranges from 25 to 35 degrees. Different roller surface hardnesses correspond to different acting areas, and setting the hardness as the aforementioned H1, H3 and H2 can further significantly improve the lamination effect.

[0089] See Figure 1 , Figures 3-10The composite foil apparatus 10 provided in one embodiment of this application further includes an unwinding device 104 and a winding device 105; the unwinding device 104 is used at least to unwind the substrate; the winding device 105 is used at least to wind the composite foil; after the substrate is unwound from the unwinding device 104, it passes through the gradient heating device 101 and the composite device 103 in sequence, and is then combined with the foil layer to form a composite foil which is then wound up by the winding device 105.

[0090] Understandably, this application does not impose special limitations on the structure of the unwinding device 104, as long as it achieves the purpose of unwinding the substrate. Exemplarily, the unwinding device 104 includes an unwinding support and an unwinding shaft. The unwinding support is further arranged with a tension adjusting roller, a tension detecting roller, and at least one guide roller. The relative positions of the tension adjusting roller, tension detecting roller, and guide roller are configured such that the substrate on the unwinding shaft passes through the tension adjusting roller, tension detecting roller, and guide roller, and the first surface side of the substrate abuts against at most one of the rollers of the tension adjusting roller, tension detecting roller, or guide roller. The first surface side is the surface side of the substrate used for laminating with a downstream material layer (such as metal foil). Further, the tension adjusting roller and tension detecting roller are arranged adjacent to each other. Even further, the tension adjusting roller and tension detecting roller are arranged sequentially in the unwinding direction. Even further, the guide roller is arranged before or after the tension adjusting roller and tension detecting roller. The adjacent arrangement of the tension adjusting roller and the tension detection roller improves the accuracy of tension detection and adjustment. When the tension adjusting roller adjusts, the adjacent tension detection roller can instantly and accurately detect the corresponding tension, facilitating more precise tension control and adjustment. Sequential arrangement of the tension adjusting roller and the tension detection roller in the unwinding direction improves the tension stability between the unwinding device 104 and the composite process. Alternatively, the guide roller can be positioned between the tension adjusting roller and the tension detection roller, with the tension adjusting roller located closer to the unwinding shaft and the tension detection roller located further away from the unwinding shaft in the unwinding direction.

[0091] Understandably, this application does not impose any special restrictions on the structure of the winding device 105, as long as it can achieve the purpose of winding the substrate.

[0092] See Figure 1 , Figure 3 , Figure 5 , Figures 7-10The composite foil apparatus 10 provided in one embodiment of this application further includes a gradient cooling device 106, located downstream of the composite apparatus 103, for gradient cooling of the composite foil. The substrate and adhesive layer have a certain temperature after gradient heating treatment, the metal foil prepared by the foil-making apparatus 102 also has a certain temperature, and the composite foil obtained by the composite apparatus 103 has a certain temperature. Gradient cooling of the composite foil avoids the problem of deformation caused by the sudden cooling and shrinkage of the adhesive layer, and avoids problems such as surface pits, wrinkles, or edge warping that may occur in the lamination of materials with a thickness of micrometers due to the different thermal expansion coefficients of the substrate, adhesive layer, and metal foil layer. This improves the composite effect and enhances the uniformity, structural stability, and mechanical properties of the composite foil.

[0093] Understandably, this application does not impose any special restrictions on the structure of the gradient cooling device 106, as long as it can achieve the purpose of gradient cooling of the composite foil. Optionally, the gradient cooling device 106 can be a series structure of independent thermoelectric refrigeration units, a multi-channel independent temperature-controlled fluid circulation structure, a gradient phase change material / refrigerant heat absorption structure, or a movable cold source / gradient slider structure.

[0094] For example, a gradient cooling device 106 provided in one embodiment of this application includes:

[0095] A cooling substrate having a cooling surface for contacting the composite foil; the cooling substrate having multiple independent fluid channels spaced along the transport direction of the composite foil; and

[0096] Multiple independent refrigerant circulation loops.

[0097] For example, each refrigerant circulation loop independently includes:

[0098] Circulating pump;

[0099] Heat exchanger or refrigeration unit;

[0100] Connecting pipes connect the circulating pump and heat exchanger or refrigeration unit to the corresponding independent fluid channels in the cooling base plate, forming a closed loop;

[0101] Temperature sensors are respectively disposed on the cooling surface near the cooling substrate and corresponding to each fluid channel, or disposed in the fluid of each closed loop; and

[0102] The control system is communicatively connected to each heat exchanger or refrigeration unit, and / or communicatively connected to each circulating pump, and is configured to:

[0103] Receive temperature signals from various temperature sensors;

[0104] Based on the preset temperature gradient curve or the target temperature value of each channel, the output cooling capacity of the refrigeration unit in each closed loop (such as compressor power, liquid nitrogen flow rate, constant temperature bath temperature) is independently controlled, and / or the flow rate of each circulation pump is independently controlled, so that the refrigerant flowing through each independent fluid channel is maintained at the set temperature, thereby forming a corresponding cooling temperature gradient on the cooling surface of the cooling substrate along the transport direction of the composite foil.

[0105] Understood, this application does not limit the structure of the heat exchanger or refrigeration unit. Exemplarily, the heat exchanger or refrigeration unit includes, but is not limited to, a thermoelectric refrigeration module, a compressor refrigeration system, or a cryogenic liquid circulation system. Further, the heat exchanger or refrigeration unit includes, but is not limited to, one or more combinations of a compressor-condenser-expansion valve system, a liquid nitrogen storage tank heat exchanger, and a constant temperature bath.

[0106] Understandably, this application does not impose any special limitations on the cooling substrate. Exemplarily, the cooling substrate is made of a highly thermally conductive material, such as copper and / or aluminum. Furthermore, thermally conductive barriers or insulating materials are provided between multiple independent fluid channels to reduce thermal crosstalk between adjacent channels.

[0107] Understandably, the adhesive layer on the surface of the substrate in this application can be applied before unwinding or applied by the adhesive applicator 107 after unwinding.

[0108] In one embodiment, the adhesive layer on the substrate surface is applied before unwinding. The unwound material is a composite film layer, including a substrate and an adhesive layer disposed on the substrate surface; the first surface side is the side of the substrate with exposed adhesive. Further, the first surface side of the composite film roll is covered with a release film layer; the unwinding device 104 also includes a peeling member, which is configured to peel off the release film layer before the tension adjusting roller, and the peeling member also rewinds the release film layer while peeling it off. Furthermore, the unwinding device 104 is arranged in sequence as a guide roller, a tension adjusting roller, and a tension detection roller in the unwinding direction, and in the roller travel direction, the peeling member is disposed between the tension adjusting roller and the guide roller, which facilitates real-time adjustment based on the tension changes caused by the peeling process, thereby ensuring smooth and flat unwinding while peeling.

[0109] In one embodiment, see Figures 4-7 as well as Figures 9-10 The adhesive layer on the substrate surface is applied by the coating device 107 after the substrate is unwound. The adhesive layer can significantly improve the bonding stability and tightness between the substrate layer and the foil layer. Understandably, this application does not impose any special restrictions on the structure of the coating device 107.

[0110] Further, see Figures 6-7 as well as Figure 10The composite foil apparatus 10 provided in one embodiment of this application also includes a substrate surface treatment apparatus 108, located downstream of the unwinding apparatus 104 and upstream of the coating apparatus 107, for performing surface treatment on the substrate.

[0111] Optionally, the substrate surface treatment device 108 is a chemical micro-etching device. The chemical micro-etching device is used at least to micro-etch the surface of the thin film substrate layer to improve the surface roughness of the substrate. When the adhesive coating device 107 applies adhesive to the surface of the substrate layer, as the adhesive forms an adhesive layer, the side of the adhesive layer close to the substrate layer will form an interlocking state with the micro-etched depressions and other positions of the substrate layer. At this time, the adhesive layer can be an adhesive layer that is more compatible with the foil layer. In addition to the adhesiveness of the adhesive layer itself, the interlocking on one side and the affinity on the other side are used to improve the overall bonding strength of the composite foil.

[0112] Furthermore, the chemical micro-etching apparatus applies a chemical treatment agent to micro-etch the surface of the substrate layer. The chemical micro-etching apparatus includes a roller coating device, a spraying device, and / or an immersion device. The micro-etching treatment device can adopt a roller structure, a spraying structure, or an immersion tank structure, or a combination of two or more of these. In specific applications, different flow guide roller combinations can be installed before the chemical micro-etching apparatus to guide different chemical micro-etching apparatus structures, depending on the specific requirements. Unlike common corona treatment methods, this application uses a chemical treatment agent as the main component for chemical micro-etching, so it only needs to be applied to the surface of the substrate layer. Roll coating, spraying, or immersion can effectively coat the liquid onto the substrate layer, thereby performing micro-etching. Therefore, it does not require a complex application process, is simple to operate, and can effectively ensure that all positions on the surface of the substrate layer are micro-etched. Furthermore, the chemical micro-etching apparatus also includes a residue removal device, located downstream of the chemical micro-etching apparatus; the residue removal device includes a squeezing device, a blowing device, and / or a drying device.

[0113] See Figures 8-10 The composite foil apparatus 10 provided in one embodiment of this application further includes a passivation treatment apparatus 109, located downstream of the composite apparatus 103 and upstream of the winding apparatus 105. This apparatus is used to passivate the composite foil, preventing oxidation reactions caused by contact with oxygen, water, acids, etc., in the external environment, thereby maintaining its surface smoothness and electrical properties. It is understood that this application does not impose special limitations on the structure of the passivation treatment apparatus 109 or the passivation solution. Passivation solutions include, but are not limited to, alkaline or acidic cleaning solutions, sodium molybdate, or phytic acid.

[0114] Another objective of this application is to provide a composite current collector production system, including the composite foil device 10 described above. Based on this composite current collector production system, it is applicable to the lamination of ultra-thin foil materials during the composite current collector production process, achieving lamination while avoiding the transmission of ultra-thin materials, thereby obtaining a tightly laminated, high-quality composite material with a smooth surface. The overall composite current collector production system has a simple structure, is easy to deploy and install, and the resulting composite product has correspondingly good performance.

[0115] Another objective of this application is to provide a composite current collector produced by the aforementioned composite current collector production system. The resulting composite current collector exhibits tightly bonded material layers that are not easily separated, and a smooth composite interface, thus possessing excellent composite current collector performance.

[0116] The technical solution of this application will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. However, those skilled in the art will understand that the embodiments described below are only some embodiments of this application, not all embodiments, and are only used to illustrate this application, and should not be regarded as limiting the scope of this application. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0117] 1. Raw material description:

[0118] Both the PET substrate and rosin resin adhesive are commercially available.

[0119] 2. Testing Method:

[0120] (1) The mechanical properties test method of composite copper foil refers to GB / T29847-2013, and the test instrument is Dongguan Sitai ST-D200.

[0121] (2) Peelability of copper foil: Peel the composite copper foil off the cathode roller and observe whether there is copper foil residue on the cathode roller. According to the percentage of copper foil residue on the cathode roller to the area of ​​electrolytic copper foil, it is divided into three levels: Level I: the area of ​​residual copper foil is ≤1%, easy to peel; Level II: 1% < the area of ​​residual copper foil is ≤10%, the copper foil tears when peeling, and the peelability is poor; Level III: 10% < the area of ​​residual copper foil, and the peelability is poor.

[0122] Example 1

[0123] See Figure 4 This embodiment provides a composite copper foil device 10, which includes, from upstream to downstream:

[0124] Unwinding device 104 is used for unwinding PET substrate;

[0125] The adhesive applicator 107 is used to apply an adhesive layer to one side of the PET surface.

[0126] The gradient heating device 101 is used to gradient heat the substrate and the adhesive layer disposed on one side of the substrate. The temperature gradient increases along the transport direction of the substrate, and the heating curve is a linear gradient heating. The first stage heats up to 40°C, the second stage heats up to 50°C, and the third stage heats up to 60°C.

[0127] The copper foil production device 102 is used to produce ultra-thin copper foil. The electrolyte formula and electrolysis parameters are set in a conventional manner.

[0128] Composite apparatus 120 is used to composite PET substrate and copper foil to obtain composite copper foil; and

[0129] The winding device 105 is used to wind up composite copper foil, which is a single-sided composite copper foil with a structure of PET substrate, adhesive layer and ultra-thin copper foil.

[0130] The single-sided composite copper foil was unwound after being wound up. Adhesive was applied to the other surface of the substrate where the copper foil was not laminated. Gradient heating, lamination and winding operations were repeated to prepare double-sided composite copper foil. The appearance of the double-sided composite copper foil was observed and mechanical properties were tested. The thickness and performance results of each layer are shown in Table 1 below.

[0131] Comparative Example 1

[0132] See Figure 11 This comparative example provides a first comparative composite copper foil device 11, which includes, from upstream to downstream:

[0133] Unwinding device 104 is used for unwinding PET substrate;

[0134] The adhesive applicator 107 is used to apply an adhesive layer to one side of the PET surface.

[0135] Heating device 110 is used to heat the substrate and the adhesive layer on one side of the substrate, directly raising the temperature to 60°C;

[0136] The copper foil production device 102 is used to produce ultra-thin copper foil. The electrolyte formula and electrolysis parameters are set in a conventional manner.

[0137] Composite apparatus 103 is used to composite PET substrate and copper foil to obtain composite copper foil; and

[0138] The winding device 105 is used to wind up composite copper foil, which is a single-sided composite copper foil with a structure of PET substrate, adhesive layer and ultra-thin copper foil.

[0139] The single-sided composite copper foil was unwound after being wound up. Adhesive was applied to the other surface of the substrate where the copper foil was not laminated. The heating, lamination and winding operations were repeated to prepare double-sided composite copper foil. The appearance of the double-sided composite copper foil was observed and its mechanical properties were tested. The thickness and performance results of each layer are shown in Table 1 below.

[0140] Comparative Example 2

[0141] See Figure 12 This comparative example provides a second comparative composite copper foil device 12, which includes, from upstream to downstream, the following components:

[0142] Unwinding device 104 is used for unwinding PET substrate;

[0143] The adhesive applicator 107 is used to apply an adhesive layer to one side of the PET surface.

[0144] The copper foil production device 102 is used to produce ultra-thin copper foil. The electrolyte formula and electrolysis parameters are set in a conventional manner.

[0145] Hot-press laminating apparatus 120, including hot-press laminating roller 1201 and peeling roller 1202, is set to 60°C for hot-press laminating PET, adhesive layer and copper foil to obtain composite copper foil; and

[0146] The winding device 105 is used to wind up composite copper foil, which is a single-sided composite copper foil with a structure of PET substrate, adhesive layer and ultra-thin copper foil.

[0147] The single-sided composite copper foil was unwound after being wound up. Adhesive was applied to the other surface of the substrate where the copper foil was not laminated. The hot-pressing and winding operations were repeated to prepare double-sided composite copper foil. The appearance of the double-sided composite copper foil was observed and its mechanical properties were tested. The thickness and performance results of each layer are shown in Table 1 below.

[0148] Comparative Example 3

[0149] See Figure 13 This comparative example provides a third comparative composite copper foil device 13, which includes, from upstream to downstream:

[0150] Unwinding device 104 is used for unwinding PET substrate;

[0151] The adhesive applicator 107 is used to apply an adhesive layer to one side of the PET surface.

[0152] The copper foil production device 102 is used to produce ultra-thin copper foil. The electrolyte formula and electrolysis parameters are set in a conventional manner.

[0153] Composite apparatus 103 is used to composite PET substrate and copper foil to obtain composite copper foil; and

[0154] The winding device 105 is used to wind up composite copper foil, which is a single-sided composite copper foil with a structure of PET substrate, adhesive layer and ultra-thin copper foil.

[0155] Unwind the single-sided composite copper foil after winding, apply adhesive to the other surface of the substrate where the copper foil is not laminated, repeat the lamination and winding operations to prepare double-sided composite copper foil, observe the appearance of the double-sided composite copper foil and conduct mechanical property tests. The thickness and performance results of each layer are shown in Table 1 below, " / " indicates none.

[0156] Table 1. Parameters and performance results of double-sided composite copper foil with a total thickness of approximately 8.0 μm.

[0157]

[0158] The double-sided composite copper foil prepared in Example 1 has a smooth surface with no obvious wrinkles or warping; the double-sided composite copper foil prepared in Comparative Example 1 has a relatively smooth surface in some parts, but some surfaces have "earthworm-like" wrinkles, which the inventors speculate are caused by the shrinkage of the adhesive layer; the double-sided composite copper foil prepared in Comparative Example 2 has an extremely uneven surface with many wrinkles and warped edges.

[0159] As can be seen from the above, compared with comparative examples 1 to 3, embodiment 1 of this application can improve the adhesion of the adhesive layer by gradually heating the substrate and adhesive layer before lamination, so that the substrate and copper foil are firmly bonded together during subsequent roll lamination, improving the peelability of the copper foil and improving the uniformity, structural stability and mechanical properties of the composite copper foil. It can also avoid heat deformation of the substrate and shrinkage of the adhesive layer, and reduce wrinkles and edge warping of the composite copper foil.

[0160] 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.

[0161] 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 utility model 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 composite foil device, characterized in that, include: A gradient heating device is used to gradient heat a substrate and an adhesive layer disposed on at least one side surface of the substrate, wherein the temperature gradient increases along the transport direction of the substrate; A foil-forming apparatus, for at least forming a foil layer, is located downstream of the gradient heating apparatus along the transport direction of the substrate; and A composite device for bonding the substrate and the foil layer to obtain the composite foil.

2. The composite foil device according to claim 1, characterized in that, After gradient heating, the temperature of the substrate and the adhesive layer is T1, and the heat distortion temperature of the substrate is T2. T1 and T2 satisfy: T1 < T2.

3. The composite foil device according to claim 1, characterized in that, The gradient heating curve is a combination of one or more of the following: linear temperature gradient, nonlinear temperature gradient, and step temperature gradient.

4. The composite foil device according to claim 1, characterized in that, The gradient heating device includes: A heating chamber defining a channel for the substrate and adhesive layer to pass through and for heat treatment; and, Multiple heating units are arranged sequentially along the transmission direction of the substrate and each maintains a different set temperature, thereby forming a continuous or stepped temperature gradient field to gradually increase the temperature of the substrate and the adhesive layer.

5. The composite foil device according to claim 4, characterized in that, Each of the heating units independently includes: a heating element, a temperature sensor, an independent temperature control module, and a control system; The independent temperature control module is electrically connected to the heating element and the temperature sensor; the control system is communicatively connected to each independent temperature control module and is configured as follows: (1) Receive temperature signals from each of the temperature sensors; (2) Based on the preset temperature gradient curve or the target temperature value of each heating unit, send control commands to the corresponding temperature control module; (3) Each of the heating units is controlled to maintain a different set temperature in the channel along the transmission direction of the substrate, thereby forming a continuous or stepped temperature gradient field.

6. The composite foil device according to claim 1, characterized in that, It also includes a gradient cooling device, located downstream of the composite device, for gradient cooling of the composite foil.

7. The composite foil device according to claim 6, characterized in that, The gradient cooling device includes: A cooling substrate having a cooling surface for contacting a composite foil; the cooling substrate having a plurality of independent fluid channels spaced along the transport direction of the composite foil; and Multiple independent refrigerant circulation loops.

8. The composite foil device according to any one of claims 1 to 7, characterized in that, Satisfy one or more of the following (1)~(2): (1) The foil-forming device includes a tank for containing electrolyte and a rotatable cathode roller, a portion of which can be immersed in the electrolyte to form the foil layer on the surface of the cathode roller; (2) The composite device includes a pressure roller assembly and a guide roller; the pressure roller assembly and the cathode roller surface are configured such that: the cathode roller surface is used as the support surface, the pressure roller assembly is arranged at intervals along the circumference of the cathode roller, and the pressure roller assembly presses down on the substrate and the foil layer to obtain the composite foil; the guide roller is used to pull the composite foil away from the cathode roller surface.

9. The composite foil apparatus according to any one of claims 1 to 7, characterized in that, Satisfy one or more of the following conditions (1) to (3): (1) The substrate comprises one of 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; (2) The adhesive layer includes one of rosin resin, terpene resin, petroleum resin, polyurethane resin, polyacrylic resin, epoxy resin, phenolic resin, polyester resin, polyimide, organosilicon polymer and its modified compounds, and polyolefin and its modified compounds; (3) The foil layer includes one or more combinations of copper foil and aluminum foil.

10. A composite current collector production system, characterized in that, Includes the composite foil device according to any one of claims 1 to 9.

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