Composite current collector and forming process method and application thereof

Abstract

The invention discloses a composite current collector and a forming process method and application thereof. The composite current collector is characterized in that one or more polymer curing layers are formed on a first metal layer through thermal evaporation or coating curing, and second metal layers are formed between the polymer curing layers and / or on the polymer curing layers through evaporation; the forming process method comprises the following steps: forming a polymer curing layer on a first metal layer through thermal evaporation or coating; and repeating thermal evaporation or coating curing and evaporation processes to form a multi-layer stacked structure. The resistivity of the composite current collector is effectively reduced, and the production efficiency of the composite current collector is improved; the metal layer is made of common metal materials in the market, sputtering points do not exist on the metal layer formed through evaporation, the polymer layer is formed through thermal evaporation or coating and then through electron beam or ultraviolet curing, the adhesive force between the metal layer and the polymer layer is effectively improved, and the problems that the electric performance of the composite current collector is reduced, and the service life of the composite current collector is prolonged are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of current collectors, and particularly to a composite current collector, a forming process method thereof, and an application thereof. Background Art

[0002] As an innovative material with great potential in the field of lithium batteries, the composite current collector is a multi-layer material structure used to replace the forming process method of traditional metal foils. The composite current collector usually consists of an insulating layer and a metal layer, and its typical design includes: metal-polymer-metal (such as aluminum-polymer-aluminum or copper-polymer-copper), with a light polymer material (such as PET, PI) in the middle layer and thin metal layers on both sides; the insulating layer uses a polymer material, which can effectively block the risk of short circuit between the positive and negative electrodes while reducing the weight of the current collector, improving the safety performance of the battery; the metal layer is responsible for conducting current to ensure the electrical conductivity of the current collector; with these characteristics, the composite current collector can effectively improve the energy density of lithium batteries while significantly reducing its own weight, reducing metal consumption during the production process, thereby reducing costs; and it can enhance flexibility, reduce the risk of pole piece fracture, and adapt to high-deformation scenarios (such as flexible batteries).

[0003] However, the current preparation process of the composite current collector mainly realizes the preparation of the metal layer through methods such as magnetron sputtering, electroplating in water, evaporation, and pasting. The compactness of the film layer prepared during this process is lower than that of the original metal, and the production efficiency is relatively low (taking the negative current collector as an example, the resistivity of the composite copper current collector produced by the traditional method is 2 - 2.5×10 -8 Ω·m, and the speed of the negative current collector is 5 - 10 m / min; taking the positive current collector as an example, the resistivity of the composite aluminum produced by the traditional method is 3.2 - 4.0×10 -8 Ω·m, and the speed of the positive current collector is 10 - 15 m / min); and there is a problem that the sputtering points of the positive composite current collector cannot be eliminated, and there is a problem that the bonding force between the polymer substrate and the metal layer of the negative composite current collector is relatively low, resulting in a decline in the electrical performance and service life of the composite current collector. Summary of the Invention

[0004] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0005] The purpose of the present invention is to solve the disadvantages existing in the prior art, and to propose a composite current collector, a forming process method thereof, and an application thereof.

[0006] To achieve the above object, in a first aspect, the present invention provides a composite current collector, comprising: a first metal layer and a polymer cured layer; One or more layers of the polymer cured layer are formed on the first metal layer by thermal evaporation or coating and curing, and a second metal layer is formed by evaporation on and / or between the polymer cured layers.

[0007] In some embodiments, the thickness of the first metal layer is 1-20 μm, and the thickness of the second metal layer is 0.1-20 μm.

[0008] In some embodiments, the thickness of the polymer cured layer is 0.1-10 μm.

[0009] In a second aspect, the present invention further provides a forming process method for a composite current collector for preparing the composite current collector as described in the first aspect. The forming process method includes: S100, pre-treating the surface of the first metal layer; S200, forming a polymer cured layer on the first metal layer by thermal evaporation or coating.

[0010] In some embodiments, in S100, the pre-treatment process is to perform plasma or corona treatment on the first metal layer under the action of an electromagnetic field.

[0011] In some embodiments, S200 includes: S210a, in a vacuum environment, heating the evaporation chamber to a preset temperature, injecting a polymer material, and thermally evaporating it onto the first metal layer through a nozzle after vaporization; S220a, forming a polymer cured layer by electron beam or ultraviolet curing of the polymer material; Or S210b, in a vacuum environment, extracting the polymer material, infiltrating it, and coating it onto the first metal layer through a mold; S220b, forming a polymer cured layer by electron beam or ultraviolet curing of the polymer material.

[0012] In some embodiments, S200 includes: S210c, in an atmospheric environment, extracting the polymer material, infiltrating it, and coating it onto the first metal layer through a mold; S220c, forming a polymer cured layer by electron beam or ultraviolet curing of the polymer material.

[0013] In some embodiments, it further includes S300, and S300 includes: S300a: Form a second metal layer on the polymer curing layer through an evaporation process. Repeat S200 and S300a to form a multi-layer stacked structure. Or S300b: Thermally evaporate or coat on the polymer curing layer to form another polymer curing layer, and form a second metal layer through an evaporation process. Or S300c: Thermally evaporate or coat on the polymer curing layer where a set of first metal layers has been cured to form another polymer curing layer, stack it with the polymer curing layer where another set of the same or different first metal layers has been cured, and form a multi-layer stacked structure through electron beam or ultraviolet curing.

[0014] In some embodiments, the preset temperature range is 200 - 400 °C, and the conveying speed of the first metal layer is 10 - 300 m / min.

[0015] In a third aspect, the present invention also provides an application of the composite current collector, and the composite current collector is applied to the fields of lithium batteries, capacitors, and smart wearables.

[0016] The present invention has the following beneficial effects: 1. In the present invention, a polymer curing layer is formed by thermal evaporation or coating and curing on the first metal layer, and then a second metal layer is formed on the polymer curing layer through an evaporation process; and the thermal evaporation / coating and curing and evaporation processes can be repeated according to production needs to form a multi-layer stacked structure, effectively reducing the resistivity of the composite current collector without changing the resistivity of the existing materials, and improving the production efficiency of the composite current collector. 2. In the present invention, common metal materials on the market are used for the metal layer, and there are no sputtering points on the evaporated metal layer, while the polymer layer is first formed by thermal evaporation or coating and then by electron beam or ultraviolet curing, effectively improving the adhesion between the metal layer and the polymer layer, and solving the problems of the decline in the electrical properties and service life of the composite current collector. Description of the Drawings

[0017] Figure 1 It is a schematic diagram of the film layer structure of the composite current collector proposed by the present invention; Figure 2 It is a schematic flow chart of the forming process method of the composite current collector proposed by the present invention Figure 1 ; Figure 3 It is a schematic flow chart of the forming process method of the composite current collector proposed by the present invention Figure 2 ; Figure 4 It is a schematic flow chart of the forming process method of the composite current collector proposed by the present invention Figure 3 。

[0018] Legend Explanation: 1. First metal layer; 2. Polymer curing layer; 3. Second metal layer. Detailed implementation manners

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0020] The embodiments of the present application provide a composite current collector and its forming process method and application, which solve the problems in the prior art that the compactness of the prepared film layer is lower than that of the original metal, and the production efficiency is relatively low; and there are problems that the sputtering points of the positive composite current collector cannot be eliminated, and the binding force between the polymer substrate and the metal layer of the negative composite current collector is relatively low, resulting in a decline in the electrical performance and service life of the composite current collector. The present application forms a multi-layer stacked structure by repeating the thermal evaporation / coating curing and evaporation processes according to production needs, effectively reducing the resistivity of the composite current collector without changing the resistivity of the existing materials, and improving the production efficiency of the composite current collector.

[0021] Please refer to the following embodiments for details: Refer to Figure 1 , an embodiment of a composite current collector provided by the present invention, the specific structure includes: a first metal layer 1 and a polymer curing layer 2. Among them, one or more polymer curing layers 2 are formed on the first metal layer 1 by thermal evaporation or coating curing, and a second metal layer 3 is formed by evaporation between and / or on the polymer curing layers 2.

[0022] It should be noted in detail that during actual production, first, a polymer material (such as acrylate polymers and other materials that can be cured by electron beam or ultraviolet light) is applied on the first metal layer 1 (usually aluminum foil or copper foil) by means of precision thermal evaporation or slot coating, and then a dense polymer curing layer 2 is formed through electron beam curing or ultraviolet light curing treatment; then a second metal layer 3 (for example, aluminum can be used for the positive electrode and copper can be used for the negative electrode) is formed on the bottom surface of the cured polymer layer by evaporation process; and these process steps can be cycled multiple times according to actual production requirements, that is, by repeating the thermal evaporation / coating curing and metal evaporation processes, a composite current collector with a multi-layer alternating stacked structure is constructed.

[0023] Among them, electron beam curing uses high-energy electron beams (usually 50 - 300 keV) to directly bombard polymer monomers or prepolymers, generating active free radicals or ions through ionization, triggering rapid cross-linking reactions, and completing curing within milliseconds. The curing speed is faster than UV curing and is not affected by pigments / fillers, and can penetrate opaque materials to achieve overall cross-linking; there is no photoinitiator, avoiding the problem of small molecule migration, and the product is purer; it operates at room temperature and there is no solvent volatilization. Correspondingly, UV curing uses ultraviolet light with a specific wavelength (usually 200 - 400 nm) to activate the photoinitiator, causing it to decompose and generate active free radicals or cations, thereby triggering a chain polymerization reaction of polymer monomers or prepolymers, and completing cross-linking curing within seconds; it is energy-efficient, with a fast curing speed, low energy consumption, and precise control.

[0024] It can be understood that by optimizing the process sequence and parameters, while maintaining the intrinsic resistivity of the original material, the overall resistance of the composite current collector is effectively reduced (the resistivity of the composite copper current collector produced by the new production process is 1.7 - 1.85×10 -8 Ω·m, and the resistivity of the composite aluminum current collector produced by the new production process is 2.6 - 2.9×10 -8 Ω·m); by adopting an efficient continuous production process, the production speed of traditional composite current collectors is increased from 5 - 15 m / min to 10 - 300 m / min, effectively improving production efficiency; and by evaporating the polymer, after the polymer is embedded on the surface of the metal film, the interfacial adhesion force is increased by more than 2 - 5 times.

[0025] Referring to Figures 2 - 4 , the present invention also provides an embodiment of a forming process method for a composite current collector, used to prepare the composite current collector as in the above embodiment. The forming process method includes: S100, performing pretreatment on the surface of the first metal layer 1; S200, forming a polymer curing layer 2 on the first metal layer 1 by thermal evaporation or coating.

[0026] It should be elaborated in detail that in S100, the pretreatment process is to perform plasma or corona treatment on the first metal layer 1 under the action of an electromagnetic field. It can be understood that: (1) By applying a high-frequency electric field (usually 13.56 MHz radio frequency or 2.45 GHz microwave) in a vacuum chamber, the process gas (such as argon, oxygen, or nitrogen) introduced is ionized to form a low-temperature plasma. Under the constraint of a magnetic field (using a permanent magnet array or electromagnetic coil), electrons are restricted to perform helical motion, generating an electron multiplication effect and continuously bombarding the surface of the metal film: on the one hand, surface contaminants (including organic substances and oxides) are removed by physical sputtering of argon ions, forming a nanoscale rough surface (Ra increases by 20 - 100 nm); on the other hand, oxygen / nitrogen plasma introduces active groups such as hydroxyl (-OH) and carboxyl (-COOH) on the surface, thereby increasing the surface energy, enhancing the metal / polymer interface bonding strength by 2 - 3 times, and at the same time maintaining the electrical conductivity of the metal body (resistivity change < 3%), providing an ideal interface environment for the subsequent thermal evaporation process; (2) Corona treatment uses high-voltage discharge to generate plasma on the surface of metals (such as aluminum foil, copper foil), forms micron-scale roughness through physical etching, and at the same time introduces oxygen-containing polar groups (-OH, -COOH), thereby significantly increasing the surface energy and enhancing the adhesion to polymer materials, and further improving the uniformity of the subsequent thermal evaporation or coating process and avoiding coating defects; moreover, corona treatment has strong controllability, and parameters can be adjusted online and the effects can be detected.

[0027] Please continue to refer to Figure 3 , in this embodiment, S200 includes: S210a, in a vacuum environment, heat the evaporation chamber to a preset temperature, inject the polymer material, and after vaporization, thermally evaporate it onto the first metal layer 1 through a nozzle; S220a, form a polymer cured layer 2 by electron beam or ultraviolet curing of the polymer material; Or S210b, in a vacuum environment, extract the polymer material, infiltrate it, and then coat it onto the first metal layer 1 through a mold; S220b, form a polymer cured layer 2 by electron beam or ultraviolet curing of the polymer material; Or S210c, in an atmospheric environment, extract the polymer material, infiltrate it, and then coat it onto the first metal layer 1 through a mold; S220c, form a polymer cured layer 2 by electron beam or ultraviolet curing of the polymer material.

[0028] Exemplarily, the present application provides a variety of process schemes for preparing the polymer cured layer 2 in different environments, that is, the metal-polymer interface bonding is realized through different film-forming methods and different curing methods, ensuring that the cured polymer cured layer 2 can be closely attached to the first metal layer 1, the second metal layer 3, or another polymer cured layer 2: (1) Thermal evaporation process: In a high-vacuum environment (atmospheric pressure < 10 -3In Pa), the evaporation cavity is precisely heated to 200 - 400 °C to vaporize the polymer material, which is then directionally deposited on the metal surface through a precision nozzle. Subsequently, crosslinking and curing are initiated by an 80 - 150 kV electron beam or polymerization curing is initiated by 365 / 395 nm ultraviolet light; (2) Coating process: In a high-vacuum environment (atmospheric pressure < 10-3 Pa) or in an atmospheric environment (atmospheric pressure is 1.013×10 - 5 Pa), the liquid polymer precursor is uniformly coated on the metal surface by slit coating or microgravure roll coating. Subsequently, crosslinking and curing are initiated by an 80 - 150 kV electron beam or polymerization curing is initiated by 365 / 395 nm ultraviolet light.

[0029] It should be noted in detail that both process schemes for preparing the polymer cured layer 2 can make the peel strength meet the battery cycle requirements. Among them, thermal evaporation is more suitable for ultra-thin film layers below 1 μm, while the coating process is more suitable for large-scale production of 3 - 10 μm thick films, and it is preferably carried out in a high-vacuum environment.

[0030] Please continue to refer to Figure 4 , in this embodiment, it further includes S300, and S300 includes: S300a, forming a second metal layer 3 on the polymer cured layer 2 by an evaporation process, and repeating S200 and S300a to form a multi-layer stacked structure; Or S300b, thermally evaporating or coating another polymer cured layer 2 on the polymer cured layer 2, and forming a second metal layer 3 by an evaporation process; Or S300c, thermally evaporating or coating another polymer cured layer 2 on the polymer cured layer 2 where a group of first metal layers 1 have been cured, stacking it with the polymer cured layer 2 where another group of the same or different first metal layers 1 have been cured, and forming a multi-layer stacked structure by electron beam or ultraviolet curing.

[0031] Through the above technical solutions, the present application first forms a polymer intermediate layer on a conventional metal substrate by precisely controlling the thermal evaporation or coating process and curing; subsequently, according to specific usage requirements, the stacking and curing of the same or different single-layer composite films (metal + polymer) are achieved by stacking; a second metal layer 3 is deposited on the surface of the polymer layer by using a high-vacuum electron beam evaporation process, which avoids the surface defects generated by the traditional sputtering method, ensures that there are no sputtering points on the metal layer, and can effectively improve the density and bonding strength of the film layer; by repeatedly implementing the above process, various stacked composite structures such as "metal-polymer-metal", "metal-polymer-polymer-metal", or "metal-polymer-polymer-metal" can be constructed, effectively reducing the resistivity of the composite current collector without changing the resistivity of the existing materials, and improving the production efficiency of the composite current collector; moreover, common metal materials on the market are used for the metal layer, and there are no sputtering points on the evaporated metal layer, while the polymer layer is first formed by thermal evaporation or coating and then cured by electron beam or ultraviolet light, effectively improving the adhesion between the metal layer and the polymer layer, and solving the problems of the decline in the electrical performance and service life of the composite current collector.

[0032] Example 1: Please continue to refer to Figure 1 , in this embodiment, one or more polymer cured layers 2 are formed on the first metal layer 1 by thermal evaporation or coating and curing.

[0033] Specifically, the material of the first metal layer 1 is a high-purity conductive metal material, including but not limited to aluminum foil (suitable for the positive electrode), copper foil (suitable for the negative electrode), or special steel strip (suitable for specific application scenarios); and the thickness of the first metal layer 1 is controlled within the range of 1-20 μm and can be adjusted according to specific application requirements: ultra-thin type (1-5 μm, suitable for flexible batteries), standard type (6-12 μm, conventional lithium batteries), and thickened type (13-20 μm, high-power batteries); Correspondingly, the material of the polymer cured layer 2 is a high-performance polymer, including but not limited to one or more of the following: polyolefins (polypropylene - PP, polyethylene - PE, etc.), polyesters (polyethylene terephthalate - PET, polybutylene terephthalate - PBT, polyethylene naphthalate - PEN, etc.), and special polymers (polyvinylidene fluoride - PVDF, polytetrafluoroethylene - PTFE, polyphenylene sulfide - PPS), and can be made of a single material or a combination of multiple materials; and the thickness of the polymer cured layer 2 is controlled within the range of 0.1-10 μm and can be adjusted according to specific application requirements: ultra-thin type (0.1-3 μm, suitable for high-energy density design), standard type (3-6 μm, balancing performance and cost), and thickened type (6-10 μm, enhancing mechanical strength).

[0034] It is understandable that through precise thickness control, the optimal layout of material properties can be achieved. Multiple polymer selections can meet the requirements of different battery systems. The ultra-thin design realizes lightweight while ensuring performance. The material combination has excellent electrolyte resistance and thermal stability.

[0035] Example 2: Please continue to refer to Figure 1 , on the basis of Example 1, a second metal layer 3 is formed by evaporation molding on the polymer curing layer 2.

[0036] Specifically, the material of the second metal layer 3 is a high-purity conductive metal material, including but not limited to aluminum foil (for the positive electrode matching solution), copper foil (for the negative electrode matching solution), or a special composite solution (aluminum-copper composite plating design); and the thickness of the first metal layer 1 is controlled within the range of 1 - 20 μm, which can be adjusted according to specific application requirements: ultra-thin type (0.1 - 4 μm, suitable for miniaturized battery components), standard type (4 - 12 μm, balancing conductivity and material cost), and thickened type (12 - 20 μm, for high-current application scenarios).

[0037] Example 3: Please continue to refer to Figure 1 , on the basis of Example 2, by repeatedly performing thermal evaporation or coating curing to form the polymer curing layer 2 and by thermal evaporation or coating curing to form the second metal layer 3, a multi-layer stacked structure of metal + polymer + metal… + polymer + metal is finally formed.

[0038] Example 4: Please continue to refer to Figure 1 , on the basis of Example 1, by repeatedly performing thermal evaporation or coating curing to form one or more polymer curing layers 2 of the same material or different materials, and then by thermal evaporation or coating curing to form the second metal layer 3, a multi-layer stacked structure of metal + polymer +… + polymer + metal is finally formed.

[0039] Example 5: Please continue to refer to Figure 1 , on the basis of Example 1, on a group of single composite films (the first metal layer 1 + polymer curing layer 2) in Example 1, a polymer curing layer of the same material or different materials can be formed by thermal evaporation or coating, and then stacked and cured with another group of the same or different single composite films (the first metal layer 1 + polymer curing layer 2), finally forming a multi-layer stacked structure of metal + polymer +… polymer… + polymer + metal (such as aluminum foil + polymer + polymer + polymer + copper foil, aluminum foil + polymer + polymer + polymer + aluminum foil, or copper foil + polymer + polymer + polymer + copper foil, etc.).

[0040] It can be understood that based on actual production requirements, the thermal evaporation / coating curing and evaporation processes can be flexibly repeated to construct a multi-layer stacked structure. For example, for different application scenarios, the number of stacked layers can be flexibly selected based on the mechanical properties and electrical conductivity of the current collector, and continuous and automated production can be achieved, greatly shortening the production cycle, reducing the production cost, and significantly improving the production efficiency, electrical conductivity, and service life of the composite current collector.

[0041] The square resistance of the composite current collectors prepared in the above embodiments was tested: the obtained composite current collector including the first metal layer 1, the polymer curing layer 2, and the second metal layer 3 was placed on the sample stage, and the square resistance of the sample was tested using a four-probe square resistance meter or an eddy current device.

[0042] The test results of the square resistance test are shown in Table 1 below: Table 1 - Square Resistance Test Results

[0043] It can be understood that by optimizing the process sequence and parameters, while maintaining the intrinsic resistivity of the original materials, the overall resistance of the composite current collector was effectively reduced (the resistivity of the composite copper current collector produced using the new production process is 1.7 - 1.85×10-8 Ω·m, and the resistivity of the composite aluminum current collector produced using the new production process is 2.6 - 2.9×10-8 Ω·m); by adopting an efficient continuous production process, the production speed of the traditional composite current collector was increased from 5 - 15 m / min to 10 - 300 m / min, effectively improving the production efficiency; and by evaporating the polymer, after the polymer was embedded on the surface of the metal film, the interfacial adhesion was increased by more than 2 - 5 times.

[0044] The composite current collector provided by the embodiments of the present invention can be used in the fields of lithium batteries, capacitors, and smart wearables: in the field of lithium batteries, it is composed of a polymer material and a metal layer, can replace the traditional current collector, can improve battery safety, prevent short-circuit thermal runaway, increase the energy density to extend the battery life, and can also extend the battery life; in the field of capacitors, it can improve the capacitance performance, increase the capacitance value and reduce leakage, and improve the heat dissipation performance; in the field of smart wearables, with the characteristics of being thin, flexible, and highly safe, it meets the requirements of device thinning and adapts to complex environments, stably powers the device, and improves the user experience.

[0045] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A composite current collector, characterized in that: include: a first metal layer and a polymer cured layer; One or more polymer solidified layers are formed on the first metal layer by thermal evaporation or coating solidification, and a second metal layer is evaporated and formed between the polymer solidified layers and / or on the polymer solidified layers.

2. The composite current collector according to claim 1, characterized in that: The thickness of the first metal layer is 1-20 um, and the thickness of the second metal layer is 0.1-20 um.

3. The composite current collector according to claim 1, characterized in that: The thickness of the polymer solidified layer is 0.1-10 um.

4. A forming process of a composite current collector, characterized in that: The forming process method is used to prepare the composite current collector according to any one of claims 1 to 3, and the forming process method comprises: S100, pre-treating the surface of the first metal layer; S200, forming a polymer solidified layer on the first metal layer by thermal evaporation or coating.

5. The forming process of the composite current collector according to claim 4, characterized in that: In the S100, the pretreatment process is to perform plasma or corona treatment on the first metal layer under the action of an electromagnetic field.

6. The forming process of the composite current collector according to claim 4, characterized in that: The S200 includes: S210a, in a vacuum environment, heating the evaporation chamber to a preset temperature, injecting a polymer material, and evaporating the polymer material onto the first metal layer through a nozzle after vaporization; S220a, curing the polymer material by electron beam or ultraviolet light to form a polymer cured layer; or S210b, extracting the polymer material in a vacuum environment, and coating the polymer material on the first metal layer through a mold after infiltration; S220b, forming a polymer cured layer by curing the polymer material by electron beam or ultraviolet light.

7. The forming process of the composite current collector according to claim 4, characterized in that: The S200 includes: S210c, extracting a polymer material in an atmospheric environment, and coating the polymer material on the first metal layer through a mold after infiltration; S220c, curing the polymer material by electron beam or ultraviolet light to form a polymer cured layer.

8. The forming process of the composite current collector according to claim 4, characterized in that: The method further comprises S300, wherein S300 comprises: S300a, forming a second metal layer on the polymer solidified layer by an evaporation process, and repeating S200 and S300a to form a multi-layer stacked structure; or S300b, thermally evaporating or coating on the polymer solidified layer to form another polymer solidified layer, and forming a second metal layer by an evaporation process; Or S300c, forming another polymer solidified layer on a group of first metal layer solidified polymer solidified layers by thermal evaporation or coating, stacking it with another group of the same or different first metal layer solidified polymer solidified layers, and forming a multilayer stacking structure by electron beam or ultraviolet curing.

9. The forming process of the composite current collector according to claim 6, characterized in that: The preset temperature range is 200-400° C., and the conveying speed of the first metal layer is 10-300 m / min.

10. An application of the composite current collector according to claim 1, characterized in that: The composite current collector is used in the fields of lithium batteries, capacitors and smart wearables.

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