Composite current collector and preparation method thereof
A composite current collector, prepared by electrospinning porous polymer fiber membrane and coated with copper layer, solves the problems of energy density improvement and lithium dendrite formation in lithium metal batteries, achieving high energy density and long cycle life in lithium metal batteries.
Patent Information
- Application Number
- CN202511871264.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-12
- Publication Date
- 2026-03-10
AI Technical Summary
In existing lithium metal batteries, the proportion of inactive metal foil is high, which limits the improvement of energy density. At the same time, the low electronic conductivity of copper plating makes it easy for lithium dendrites to grow, shortening the battery cycle life.
Porous polymer fiber membranes were prepared by electrospinning and coated with copper layers on both sides. Combined with functional fillers, a three-dimensional composite current collector was formed to regulate the lithium metal deposition direction and electric field distribution.
It reduces the mass of inactive materials, increases the energy density of lithium metal batteries, suppresses the formation of lithium dendrites, and extends the cycle life of batteries.
Smart Images
Figure CN121641972A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of current collector technology, specifically to a composite current collector and its preparation method. Background Technology
[0002] Lithium metal batteries, with their extremely high theoretical specific capacity and extremely low electrode potential, have become the preferred choice for next-generation high-energy-density energy storage and conversion devices. Lithium metal batteries consist of active and inactive materials. Active materials mainly include positive and negative electrode active materials, while inactive materials mainly include the separator, positive electrode current collector, negative electrode current collector, and packaging material.
[0003] To improve the energy density of lithium metal batteries, it is necessary to increase the proportion of active materials and reduce the proportion of inactive materials. Among these, metal foils, which are inactive materials, account for 15%-20% of the total battery mass. For example, copper foil is typically 4µm-10µm thick, and copper has a high density of 8.9g / cm³, which severely restricts the improvement of battery energy density.
[0004] To reduce the mass of current collectors, the industry typically uses copper plating on both sides of polymers such as polypropylene, polyimide, and polyethylene terephthalate to prepare composite current collectors. The thickness of the copper plating can be reduced to 1-2 μm. Although this reduces the mass ratio of inactive materials in lithium metal batteries, it suffers from low electronic conductivity, which can easily lead to uneven lithium metal deposition at the negative electrode and exacerbate the growth of lithium dendrites due to the "point effect," thereby shortening the cycle life of lithium metal batteries. Therefore, developing a method for preparing composite current collectors that combines lightweight properties with uniform electric field distribution has become crucial for improving the performance of lithium metal batteries. Summary of the Invention
[0005] Therefore, it is necessary to provide a composite current collector and its preparation method.
[0006] The technical solution of this invention to solve the above-mentioned technical problems is as follows: A method for preparing a composite current collector, comprising the following steps:
[0007] A polymer is added to an organic solvent to obtain an electrospinning precursor solution;
[0008] Electrospinning was performed using the electrospinning precursor solution as a substrate to obtain a polymer fiber membrane.
[0009] Copper layers are deposited on both sides of the polymer fiber membrane to obtain a composite current collector.
[0010] In one embodiment, adding the polymer to the organic solvent includes:
[0011] The polymer was added to a mixed solution of tetrahydrofuran and N,N-dimethylformamide and stirred at room temperature for 12-36 hours until the mixture was homogeneous.
[0012] In one embodiment, before adding the polymer to the mixed solution of tetrahydrofuran and N,N-dimethylformamide, the method further includes:
[0013] The functional filler was added to a mixed solution of tetrahydrofuran and N,N-dimethylformamide and then uniformly dispersed in the mixed solution of tetrahydrofuran and N,N-dimethylformamide by ultrasonic treatment.
[0014] In one embodiment, the polymer is any one of thermoplastic polyurethane elastomer rubber, polyimide, styrene-butadiene block copolymer, styrene-ethylene / butene-styrene block copolymer, polyethylene terephthalate, polypropylene, polyethylene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, polyethylene oxide, polyethylene oxide-polystyrene copolymer, poly(vinylidene fluoride-trifluoroethylene) copolymer, and cellulose.
[0015] In one embodiment, the functional filler is any one of barium titanate, zinc oxide, aluminum oxide, silicon dioxide, aluminum fluoride, sodium fluoride, lithium fluoride, lithium nitrate, lithium niobate, lithium lanthanum titanium oxide, lithium lanthanum zirconium tantalum oxide, lithium titanium aluminum phosphate, lithium germanium aluminum phosphate, heterojunction, covalent organic framework, metal-organic framework, two-dimensional transition metal carbide, nitride, and carbonitride.
[0016] In one embodiment, in a mixed solution of tetrahydrofuran and N,N-dimethylformamide, the volume ratio of the tetrahydrofuran to the N,N-dimethylformamide is 1-5:1.
[0017] In one embodiment, in the electrospinning precursor solution, the mass fraction of the polymer is 5wt%-40wt%, and the mass fraction of the functional filler is 1wt%-30wt%.
[0018] In one embodiment, the electrospinning process using the electrospinning precursor solution as a substrate includes:
[0019] The electrospinning precursor solution is loaded into a syringe, which is then connected to a spinning machine. After setting the spinning parameters, electrospinning is performed.
[0020] In one embodiment, the process of depositing copper layers on both sides of the polymer fiber membrane includes:
[0021] Copper layers with a thickness of 0.1μm-2μm are deposited on both sides of the polymer fiber membrane using thermal evaporation, magnetron sputtering, electron beam evaporation, or polymer-assisted electrodeposition.
[0022] The present invention also provides a composite current collector, which is prepared by the method for preparing the composite current collector described in any of the above embodiments.
[0023] The beneficial effects of this invention are as follows: The method for preparing a composite current collector provided by this invention involves adding a polymer to an organic solvent and mixing them uniformly to obtain an electrospinning precursor solution. Then, using the electrospinning precursor solution as a substrate, electrospinning is performed to obtain a porous polymer fiber membrane. Finally, copper layers are deposited on both sides of the polymer fiber membrane to prepare a three-dimensional composite current collector. This not only effectively reduces the areal density of the composite current collector and the mass of inactive materials in lithium metal batteries, thus improving the energy density of lithium metal batteries, but also allows the uniform potential distribution of the copper layer, polymer fiber membrane, and copper layer to control the whisker deposition direction. This macroscopically controls the dense deposition of lithium metal from the bottom up inside the composite current collector, suppressing the formation of lithium dendrites and improving the cycle life of lithium metal batteries.
[0024] Meanwhile, the porous polymer fiber membrane carries functional fillers, which can construct a built-in uniform local electric field, suppress the tip effect during lithium metal deposition, and achieve uniform lithium metal deposition from a microscopic perspective, further suppressing the formation of lithium dendrites. Attached Figure Description
[0025] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0026] Figure 1 This is a schematic flowchart of the preparation method of the composite current collector of the present invention;
[0027] Figure 2 A diagram showing the lithium metal deposition effect of a composite current collector prepared by plating copper on both sides of an existing polymer.
[0028] Figure 3 This is a diagram illustrating the lithium metal deposition effect of the composite current collector of the present invention.
[0029] Figure 4 This is a scanning electron microscope image of the composite current collector of the present invention. Detailed Implementation
[0030] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention 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 the invention.
[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.
[0032] In one embodiment, such as Figure 1 As shown, a method for preparing a composite current collector includes the following steps:
[0033] Step 110: Add the polymer to an organic solvent to obtain an electrospinning precursor solution.
[0034] In this embodiment, when preparing the electrospinning precursor solution, the polymer is added to a mixed solution of tetrahydrofuran and N,N-dimethylformamide, and stirred at room temperature for 12-36 hours until the mixture is homogeneous to obtain the electrospinning precursor solution.
[0035] Step 120: Electrospinning is performed using the electrospinning precursor solution as a substrate to obtain a polymer fiber membrane.
[0036] In this embodiment, when electrospinning with an electrospinning precursor solution as the substrate, the precursor solution is loaded into a syringe, connected to a spinning machine, and electrospinning is performed after setting the spinning parameters. This yields a porous polymer fiber membrane, resulting in a lightweight polymer fiber skeleton. This effectively reduces the areal density of the composite current collector, thereby reducing the mass of inactive materials in the lithium metal battery and increasing its energy density. Simultaneously, the porous structure facilitates lithium metal deposition, further enhancing the volumetric energy density of the lithium metal battery.
[0037] In one embodiment, before adding the polymer to the mixed solution of tetrahydrofuran and N,N-dimethylformamide, the method further includes: adding a functional filler to the mixed solution of tetrahydrofuran and N,N-dimethylformamide, and uniformly dispersing it in the mixed solution by ultrasonic treatment. Specifically, by adding the functional filler to the mixed solution of tetrahydrofuran and N,N-dimethylformamide and performing ultrasonic treatment, the cavitation effect of ultrasound can uniformly disperse the functional filler particles in the mixed solution of tetrahydrofuran and N,N-dimethylformamide. Then, the polymer is added to the mixed solution of tetrahydrofuran and N,N-dimethylformamide with the functional filler dispersed, and stirred at room temperature for 12-36 hours until a uniform mixture is obtained to obtain an electrospinning precursor solution. Thus, the polymer fiber membrane obtained by electrospinning from the electrospinning precursor solution can carry functional filler particles, that is, the lightweight polymer fiber skeleton can carry functional filler particles.
[0038] In one embodiment, the polymer is a thermoplastic polyurethane elastomer rubber, polyimide, styrene-butadiene block copolymer, styrene-ethylene / butene-styrene block copolymer, polyethylene terephthalate, polypropylene, polyethylene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, polyethylene oxide, polyethylene oxide-polystyrene copolymer, poly(vinylidene fluoride-trifluoroethylene) copolymer, or cellulose. Specifically, the polymer is used to form a porous polymer fiber membrane. For example, the polymer is a thermoplastic polyurethane elastomer rubber, which has excellent mechanical and processing properties. Using thermoplastic polyurethane elastomer rubber as a substrate, based on electrospinning, polymer fiber membranes with thicknesses ranging from hundreds of nanometers to hundreds of micrometers and high porosity can be obtained by controlling the amount of electrospinning precursor solution. This enables the convenient preparation of lightweight polymer fiber membranes.
[0039] In one embodiment, the functional filler is barium titanate, zinc oxide, aluminum oxide, silicon dioxide, aluminum fluoride, sodium fluoride, lithium fluoride, lithium nitrate, lithium niobate, lithium lanthanum titanium oxide, lithium lanthanum zirconium tantalum oxide, lithium titanium aluminum phosphate, lithium germanium aluminum phosphate, heterojunction, covalent organic framework, metal-organic framework, two-dimensional transition metal carbide, nitride, or carbonitride. Specifically, the functional filler is used to uniformly distribute on the polymer fiber membrane, which can construct a built-in uniform local electric field to suppress the tip effect during lithium metal deposition. For example, barium titanate, through the ferroelectric effect, generates a local reverse electric field during lithium metal deposition, which counteracts the electric field distortion caused by current concentration, suppresses the tip effect, and further homogenizes lithium metal deposition.
[0040] In one embodiment, in the mixed solution of tetrahydrofuran and N,N-dimethylformamide, the volume ratio of tetrahydrofuran to N,N-dimethylformamide is 1-5:1. Specifically, by setting the volume ratio of tetrahydrofuran to N,N-dimethylformamide to 4:1, the advantages of both solvents can be well combined. Tetrahydrofuran can effectively dissolve polymers, while N,N-dimethylformamide, with its moderate polarity, can uniformly disperse functional fillers. The two solvents work synergistically to ensure that the polymers are fully dissolved and the functional fillers are uniformly dispersed, avoiding problems such as agglomeration or incomplete dissolution in the electrospinning precursor solution, thereby providing a stable solution system for subsequent electrospinning.
[0041] In one embodiment, the polymer mass fraction in the electrospinning precursor solution is 5wt%-40wt%, and the functional filler mass fraction is 1wt%-30wt%. Specifically, by setting the polymer mass fraction in the electrospinning precursor solution to 5wt%-40wt% and the functional filler mass fraction to 1wt%-30wt%, the polymer can be fully dissolved and form a continuous fiber network. The polymer fiber membrane has a uniform pore structure and good connectivity, and the functional filler can form uniformly distributed electric field modulation sites in the polymer fiber membrane, thereby optimizing the structure and mechanical properties of the polymer fiber membrane.
[0042] Step 130: Copper layers are deposited on both sides of the polymer fiber membrane to obtain a composite current collector.
[0043] In this embodiment, when depositing copper layers on both sides of the polymer fiber membrane, copper layers with a thickness of 0.1 μm to 2 μm can be deposited on both sides of the polymer fiber membrane by means of thermal evaporation, magnetron sputtering, electron beam evaporation, or polymer-assisted electrodeposition. For example, by using thermal evaporation equipment and setting the evaporation parameters, a copper layer can be uniformly deposited on both sides of the polymer fiber membrane.
[0044] In this embodiment, the prepared composite current collector is a lightweight three-dimensional structure capable of uniform lithium metal deposition. This three-dimensional structure sequentially comprises a copper layer that conducts electrons, a polymer fiber film layer that does not conduct electrons, and another copper layer that conducts electrons. The uniform potential distribution allows for control of the whisker deposition direction. Specifically, the porous polymer fiber film layer allows for free lithium ion transport, but electrons cannot transport within it, enabling lithium metal to grow from bottom to top within the composite current collector, achieving dense lithium deposition. Compared to adding a lithium-loving alloy to the bottom of the three-dimensional current collector, which induces lithium metal deposition from the bottom up through the alloy layer, the composite current collector of this invention does not require an additional lithium-loving alloy layer. This avoids the volume expansion of the alloy layer during lithium metal battery cycling, which could lead to alloy layer failure, and effectively achieves dense lithium metal deposition. Meanwhile, by using functional fillers to construct a built-in uniform local electric field, the tip effect during lithium metal deposition can be suppressed, which can better suppress the formation of lithium dendrites. In this way, the electric field distribution inside the composite current collector can be controlled from both microscopic and macroscopic directions, suppressing the formation of lithium dendrites and achieving dense deposition of lithium metal, thereby improving the cycle life of lithium metal batteries.
[0045] This invention provides a method for preparing a composite current collector. A polymer is added to an organic solvent and mixed uniformly to obtain an electrospinning precursor solution. Then, using the electrospinning precursor solution as a substrate, electrospinning is performed to obtain a porous polymer fiber membrane. Finally, copper layers are deposited on both sides of the polymer fiber membrane to prepare a three-dimensional composite current collector. This method not only effectively reduces the areal density of the composite current collector and the mass of inactive materials in lithium metal batteries, thus improving the energy density of lithium metal batteries, but also allows for uniform potential distribution to control the whisker deposition direction. This macroscopically controls the dense deposition of lithium metal from the bottom up within the composite current collector, suppressing lithium dendrite formation and improving the cycle life of lithium metal batteries. Simultaneously, the porous polymer fiber membrane carries functional fillers that create a built-in uniform local electric field, suppressing the tip effect during lithium metal deposition and microscopically controlling uniform lithium metal deposition, further suppressing lithium dendrite formation.
[0046] The present invention also provides a composite current collector, prepared by the method for preparing the composite current collector described in any of the above embodiments, such as... Figure 2 , Figure 3 and Figure 4As shown, when lithium metal is deposited on the upper copper layer of a composite current collector prepared by plating copper on both sides of a traditional dense polymer film, a tip effect is prone to occur. The three-dimensional porous composite current collector prepared by this invention is a lightweight three-dimensional structure that can achieve uniform lithium metal deposition. This three-dimensional structure sequentially includes a conductive copper layer, a non-conductive polymer fiber film layer, and a conductive copper layer. The porous polymer fiber film layer allows lithium ions to transport freely, but electrons cannot transport in the polymer fiber film layer, which allows lithium metal to grow from bottom to top inside the composite current collector, achieving dense lithium deposition without the need to add a lithium-affinity alloy layer. At the same time, by adding functional fillers to the electrospinning precursor solution, a non-conductive polymer fiber film layer with functional filler particles can be formed. The functional fillers, together with the built-in electric field, create a uniform local electric field, suppressing the tip effect during lithium metal deposition and better suppressing the formation of lithium dendrites. The prepared composite current collector can control the internal electric field distribution of the composite current collector from both microscopic and macroscopic directions, suppressing the formation of lithium dendrites and achieving dense lithium metal deposition, thereby improving the cycle life of lithium metal batteries.
[0047] The present invention will be further described below with reference to specific embodiments.
[0048] Example 1
[0049] A method for preparing a composite current collector includes the following steps:
[0050] Preparation of electrospinning precursor solution: 10 wt% thermoplastic polyurethane elastomer rubber was added to a mixed solution of tetrahydrofuran and N,N-dimethylformamide in a volume ratio of 4:1, and stirred at room temperature for 24 h until the mixture was homogeneous.
[0051] Electrospinning preparation of polymer fiber membranes: The electrospinning precursor solution was loaded into a syringe with a needle diameter of 2.4 mm and then connected to a spinning machine. Spinning was carried out at a speed of 1 mL / h under a DC voltage of 18 KV for a total spinning time of 3 h. Finally, a polyurethane fiber membrane with a thickness of 15 μm was collected on a collecting roller.
[0052] Preparation of composite current collector by copper plating: A copper layer with a thickness of 900 nm is uniformly deposited on both sides of the polyurethane fiber membrane using a thermal evaporation equipment, wherein the evaporation rate is 0.3-0.4 Å / s, and a composite current collector is prepared.
[0053] Example 2
[0054] A method for preparing a composite current collector includes the following steps:
[0055] Preparation of electrospinning precursor solution: 10 wt% barium titanate particles were uniformly dispersed in a mixed solution of tetrahydrofuran and N,N-dimethylformamide with a volume ratio of 4:1 by ultrasonic treatment. Then, 10 wt% thermoplastic polyurethane elastomer rubber was added to the above uniformly mixed solution and stirred at room temperature for 24 h until uniformly mixed.
[0056] Electrospinning preparation of polymer fiber membranes: The electrospinning precursor solution was loaded into a syringe with a needle diameter of 2.4 mm and then connected to a spinning machine. Spinning was carried out at a speed of 1 mL / h under a DC voltage of 18 KV for a total spinning time of 3 h. Finally, a polyurethane-barium titanate fiber membrane with a thickness of 15 μm was collected on a collecting roller.
[0057] Preparation of composite current collector by copper plating: A copper layer with a thickness of 900 nm was uniformly deposited on both sides of the polyurethane-barium titanate fiber membrane using a thermal evaporation equipment, with an evaporation rate of 0.3-0.4 Å / s, to prepare the composite current collector.
[0058] Example 3
[0059] A method for preparing a composite current collector includes the following steps:
[0060] Preparation of electrospinning precursor solution: 15 wt% lithium lanthanum zirconium tantalum oxide (LLZTO) particles were uniformly dispersed in a mixed solution of tetrahydrofuran and N,N-dimethylformamide at a volume ratio of 4:1 by ultrasonic treatment. Then, 15 wt% polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) was added to the above uniformly mixed solution and stirred at room temperature for 24 h until uniformly mixed.
[0061] Electrospinning preparation of polymer fiber membranes: The electrospinning precursor solution was loaded into a syringe with a needle diameter of 2.4 mm and then connected to a spinning machine. Spinning was carried out at a speed of 1 mL / h under a DC voltage of 18 KV for a total spinning time of 3 h. Finally, a PVDF-HFP-LLZTO fiber membrane with a thickness of 15 μm was collected on a collecting roller.
[0062] Preparation of composite current collector by copper plating: Using thermal evaporation equipment, a copper layer with a thickness of 900 nm is uniformly deposited on both sides of the PVDF-HFP-LLZTO fiber membrane, with an evaporation rate of 0.3-0.4 Å / s, to prepare the composite current collector.
[0063] Example 4
[0064] A method for preparing a composite current collector includes the following steps:
[0065] Preparation of electrospinning precursor solution: 15 wt% lithium fluoride (LiF) particles were uniformly dispersed in a mixed solution of tetrahydrofuran and N,N-dimethylformamide at a volume ratio of 4:1 by ultrasonic treatment. Then, 30 wt% polyethylene terephthalate (PET) was added to the above uniformly mixed solution and stirred at room temperature for 24 h until uniformly mixed.
[0066] Electrospinning preparation of polymer fiber membranes: The electrospinning precursor solution was loaded into a syringe with a needle diameter of 2.4 mm and then connected to a spinning machine. Spinning was carried out at a speed of 1 mL / h under a DC voltage of 18 KV for a total spinning time of 3 h. Finally, a PET-LiF fiber membrane with a thickness of 15 μm was collected on the collecting roller.
[0067] Preparation of composite current collector by copper plating: A copper layer with a thickness of 900 nm was uniformly deposited on both sides of the PET-LiF fiber membrane using a thermal evaporation equipment, with an evaporation rate of 0.3-0.4 Å / s, to prepare the composite current collector.
[0068] The composite current collectors prepared by controlling the three-dimensional current collector structure in Examples 1-4 of this invention can not only significantly reduce the areal density of the metal foil and improve the energy density of the lithium metal battery, but also achieve uniform and dense deposition of lithium metal from bottom to top inside the composite current collector, constructing a uniform local electric field with built-in electric field, thereby improving the cycle life of the lithium metal battery.
[0069] 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.
[0070] The embodiments described above are merely illustrative of several implementations of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.
Claims
1. A method of making a composite current collector, characterized by, The method comprises the following steps: adding a high molecular polymer into an organic solvent to obtain an electrospinning precursor solution; electrospinning with the electrospinning precursor solution as a base material to obtain a polymer fiber membrane; coating a copper layer on both sides of the polymer fiber membrane to obtain a composite current collector.
2. The method of making a composite current collector of claim 1, wherein, When the high molecular polymer is added into the organic solvent, the following steps are included: The high molecular polymer is added into a mixed solution of tetrahydrofuran and N,N-dimethylformamide, and stirring is performed at room temperature for 12-36 hours until the mixture is uniform.
3. The method of making a composite current collector of claim 2, wherein, Before the high molecular polymer is added into the mixed solution of tetrahydrofuran and N,N-dimethylformamide, the following steps are included: The functional filler is added into the mixed solution of tetrahydrofuran and N,N-dimethylformamide and uniformly dispersed in the mixed solution of tetrahydrofuran and N,N-dimethylformamide through ultrasonic treatment.
4. The method of making a composite current collector of claim 3, wherein, The high molecular polymer is any one of thermoplastic polyurethane elastomer rubber, polyimide, styrene-butadiene block copolymer, styrene-ethylene / butylene-styrene block copolymer, polyethylene terephthalate, polypropylene, polyethylene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, polyethylene oxide, polyethylene oxide-polystyrene copolymer, poly(vinylidene fluoride-trifluoroethylene) copolymer and cellulose.
5. The method of making a composite current collector of claim 3, wherein, The functional filler is any one of barium titanate, zinc oxide, aluminum oxide, silicon dioxide, aluminum fluoride, sodium fluoride, lithium fluoride, lithium nitrate, lithium niobate, lithium lanthanum titanium oxide, lithium lanthanum zirconium tantalum oxide, titanium aluminum lithium phosphate, germanium aluminum lithium phosphate, heterojunction, covalent organic framework, metal-organic framework, two-dimensional transition metal carbide, nitride and carbonitride.
6. The method of making a composite current collector of claim 3, wherein, In the mixed solution of tetrahydrofuran and N,N-dimethylformamide, the volume ratio of the tetrahydrofuran to the N,N-dimethylformamide is 1-5:
1.
7. The method of making a composite current collector of claim 6, wherein, In the electrospinning precursor solution, the mass fraction of the high molecular polymer is 5wt%-40wt%, and the mass fraction of the functional filler is 1wt%-30wt%.
8. The method of making a composite current collector of claim 1, wherein, When the electrospinning precursor solution is used as a base material for electrospinning, the following steps are included: The electrospinning precursor solution is loaded into a syringe and then connected to a spinning machine, and electrospinning is performed after setting the spinning parameters.
9. The method of making a composite current collector of claim 1, wherein, When the copper layer is coated on both sides of the polymer fiber membrane, the following steps are included: The copper layer with a thickness of 0.1-2 microns is coated on both sides of the polymer fiber membrane by using hot evaporation, magnetron sputtering, electron beam evaporation or polymer-assisted electroless deposition.
10. A composite current collector, characterized by, The composite current collector is prepared by the method for preparing the composite current collector according to any one of claims 1-9.