A method for large-scale preparation of ultrathin lithium anodes

Abstract

This invention belongs to the field of lithium battery technology, and particularly relates to a method for large-scale preparation of ultrathin lithium anodes. The method involves preparing lithium powder from lithium metal using emulsion methods, vacuum distillation, ultrasonic crushing, mechanical pulverization, or chemical deposition. The lithium powder and a two-dimensional material are then uniformly dispersed in solvents with similar boiling points or in the same solvent, forming a lithium powder dispersion and a two-dimensional material dispersion, respectively. The two-dimensional material dispersion and the lithium powder dispersion are cross-mixed and coated onto a substrate to obtain a lithium powder-two-dimensional material composite film. A layer of anti-lithium dendrite dispersion or a lithium-affinity material dispersion is then spin-sprayed separately onto the surface of the lithium powder-two-dimensional material composite film. The electrode is dried to remove the solution, and the film is rolled to obtain an ultrathin lithium anode. Compared to existing technologies, this invention allows for large-scale, rapid, and continuous production at low temperatures. The resulting composite film has a surface protective layer and is temporarily stable in air, facilitating direct cutting and application.

Description

Technical Field

[0001] This invention belongs to the field of lithium battery technology, and in particular relates to a method for large-scale preparation of ultrathin lithium anodes. Background Technology

[0002] Conventional methods for preparing lithium metal anodes include coating and calendering. Coating involves melting pure lithium and applying it to a substrate to form a thin film of lithium metal anode. Calendering gradually reduces the thickness of the lithium metal anode by adjusting the gap between rollers. These methods often fail to produce ultrathin films on the order of a few micrometers and are prone to cracking and oxidation. Correspondingly, methods such as the one used by Professor Cui Yi, which involve infusing graphene material into molten lithium and forming a film, have emerged. This method can obtain ultrathin lithium metal anodes, but several technical challenges remain.

[0003] Specifically, coating methods are prone to lithium metal volatilization and substrate thermal degradation during high-temperature melting, increasing production costs. Furthermore, lithium melting requires an anhydrous and oxygen-free environment and additional energy to maintain the molten state of lithium. While calendering can achieve thickness reduction, uneven roller pressure causes stress concentration on the film surface, leading to microcracks and thickness fluctuations, reducing yield. Neither coating nor calendering methods can achieve large-scale production. Although graphene reinforcement can improve the mechanical strength and thickness accuracy of films, this method faces challenges in large-scale production, including complex process control, low efficiency, and high material costs, limiting its commercial application. Moreover, the preparation of porous graphene or other porous two-dimensional materials requires pore-forming agents and other additives, resulting in high efficiency and cost, and making continuous production impossible.

[0004] Existing technologies have explored alternative methods such as electrodeposition or vacuum evaporation, but these methods also suffer from problems such as high equipment requirements, high energy consumption, and poor film adhesion, failing to meet the needs of large-scale fabrication. Therefore, there is an urgent need to develop an innovative method that is efficient, low-cost, and can stably produce ultrathin lithium metal anodes.

[0005] In view of this, the present invention aims to provide a method for large-scale preparation of ultrathin lithium anodes, which uses biaxial (dual-nozzle) rotary spraying of two-dimensional material dispersion and lithium powder dispersion to obtain a uniformly dispersed two-dimensional material lithium powder composite film. A single anti-lithium dendrite layer is sprayed on the last layer to prevent the lithium powder from contacting the external atmosphere, which facilitates subsequent operations. Summary of the Invention

[0006] To address the shortcomings of existing technologies, a method for large-scale preparation of ultrathin lithium anodes is provided. This method involves biaxial (dual-nozzle) rotary spraying of a two-dimensional material dispersion and a lithium powder dispersion to obtain a uniformly dispersed two-dimensional material-lithium powder composite film. A single anti-lithium dendrite layer is then sprayed on the last layer to prevent the lithium powder from contacting the external atmosphere, facilitating subsequent operations.

[0007] To solve the above problems and achieve the above objectives, the technical solution of the present invention is as follows:

[0008] A method for large-scale preparation of ultrathin lithium anodes includes the following steps:

[0009] The first step is to uniformly disperse lithium powder and two-dimensional materials in solvents with similar boiling points or in the same solvent to form lithium powder dispersion and two-dimensional material dispersion, respectively.

[0010] The second step involves spraying the two-dimensional material dispersion and the lithium powder dispersion onto the substrate using a biaxial rotary spray to obtain a lithium powder-two-dimensional material composite film. The lithium content can be adjusted by changing the electrode thickness, spraying rate, and lithium concentration in the raw materials.

[0011] The third step is to spin-spray a layer of anti-lithium dendrite material dispersion or lithium-affinity material dispersion onto the surface of the lithium powder-two-dimensional material composite film.

[0012] The fourth step is to dry the electrode to remove the solution and roll-press the film to obtain an ultra-thin lithium anode.

[0013] As an improvement to the method for large-scale preparation of ultrathin lithium anodes of the present invention, the two-dimensional material is at least one of graphene, MXene, molybdenum sulfide, black scale, and boron nitride (BN), or a mixture of two-dimensional non-conductive materials and conductive materials. The two-dimensional conductive materials include at least one of graphene, MXene, and novel two-dimensional polyaniline (2DPANI), and the two-dimensional non-conductive materials include at least one of molybdenum sulfide, black scale, gadolinium oxide (Gd2O5), and boron nitride (BN). Two-dimensional materials such as graphene can conduct electricity, fix lithium powder, provide a framework to facilitate lithium metal deposition, and inhibit expansion.

[0014] As an improvement to the method for large-scale preparation of ultrathin lithium anodes of this invention, MXene specifically refers to Ti2CT. x TiNbCT x Ti3CN x T x ,Ta4C3T x Nb2CT x V2CT x Nb4C3T x Mo2CT x ,(Nb 0.8 Ti 0.2 )4C3T x ,(Nb 0.8 Zr 0.2 )4C3T x Zr3C2T x and Hf3C2T x At least one of ), wherein T xThe terminals representing the surface can be combinations of various functional groups such as OH, O, F, Cl, and Br.

[0015] As an improvement to the method for large-scale preparation of ultrathin lithium anodes of the present invention, the solvent in the first step is at least one of lipids, ethers, N-methylpyrrolidone, vegetable oil and alkanes; the lipid is at least one of ethylene carbonate (EC), dimethyl carbonate (DMC) and diethyl carbonate (DEC), the ether is dimethyl ether (DME), and the alkanes are at least one of pentane, hexane, heptane, octane, nonane, decane or their isomers.

[0016] As an improvement to the method for large-scale preparation of ultrathin lithium anodes of the present invention, a dispersant may be added to the two-dimensional material dispersion. The dispersant is at least one of polyvinylpyrrolidone (PVP), sodium dodecylbenzene sulfonate (SDBS), sodium lignosulfonate (SLS), polyvinyl alcohol (PVA), polyethylene oxide, polyacrylic acid, polymethacrylic acid, and polyacrylamide.

[0017] As an improvement to the method for large-scale preparation of ultrathin lithium anodes of the present invention, the anti-lithium dendrite material includes one of fluorides, oxides and polymers, wherein the fluoride is at least one of lithium fluoride, tin fluoride, antimony fluoride, aluminum fluoride, zinc fluoride, zirconium fluoride, copper fluoride, bismuth fluoride, silver fluoride and manganese fluoride, the oxide is at least one of lithium oxide, tin oxide, antimony oxide, aluminum oxide, zinc oxide, zirconium oxide, copper oxide, bismuth oxide, silver oxide and manganese oxide, and the polymer is at least one of PEO, PAA, PVDF-HFP, PAN, PVC and PMMA.

[0018] As an improvement to the method for large-scale preparation of ultrathin lithium anodes of the present invention, the lithiophilic material is an oxide, a metal powder, or a compound with functional groups that can bind to lithium metal. The oxide is at least one of lithium oxide, tin oxide, antimony oxide, aluminum oxide, zinc oxide, zirconium oxide, copper oxide, bismuth oxide, silver oxide, and cobalt oxide. The metal powder is at least one of tin, copper, zinc, zirconium, silver, indium, gallium, and aluminum. The other compounds are at least one of organic macromolecules, polymers with hydroxyl or ketone functional groups, nitrogen, sulfur, or phosphorus doped carbon materials, 1,3,5-tris(p-formylphenyl)benzene-covalent organic framework (TFPB-COF), and metal-organic framework (MOF).

[0019] As an improvement to the method for large-scale preparation of ultrathin lithium anodes of the present invention, lithium dendrite-resistant materials or lithium-affinity materials are preloaded onto two-dimensional materials, or sprayed simultaneously with lithium powder and two-dimensional materials through a third nozzle to form a film.

[0020] As an improvement to the method for large-scale preparation of ultrathin lithium anodes of the present invention, the thickness of the lithium powder-two-dimensional material composite film is 1 micrometer-50 micrometers, the mass concentration of the two-dimensional material dispersion is 0.1-5%, the mass concentration of the lithium powder dispersion is 0.1-10%, the spraying time in the second step is 0.1-10 hours, the rotation speed is 5-2000 rpm, the drying temperature is 30-150℃, and the air pressure is 10 Pa to atmospheric pressure.

[0021] As an improvement to the method for large-scale preparation of ultrathin lithium anodes of the present invention, cross-mixing coating is performed by biaxial spin coating, or by scraping or spin coating to form a film. Preferably, it is biaxial spin coating, which is not spin coating. Spin coating uses centrifugal force to uniformly spread the solution on the substrate surface to form a film.

[0022] As an improvement to the method for large-scale preparation of ultrathin lithium anodes of the present invention, the lithium powder is prepared by emulsion method, vacuum distillation method, ultrasonic crushing method, mechanical pulverization method or chemical deposition method.

[0023] Compared with the prior art, the present invention uses a two-dimensional material dispersion and a lithium powder dispersion for cross-mixing and coating, preferably biaxial (dual nozzle) rotary spraying, which can obtain a uniformly dispersed two-dimensional material lithium powder composite film. The last layer is a single anti-lithium dendrite layer or a lithium-affinity material layer, so that the lithium powder does not come into contact with the external atmosphere, which facilitates subsequent operations.

[0024] The present invention has at least the following effects:

[0025] First, the thickness can be controlled by the material dispersion concentration, time, rotation speed, etc.

[0026] Secondly, biaxial rotary spraying allows for effective mixing and in-situ drying, reducing agglomeration. Biaxial rotary spraying can be achieved through scraping, spin coating, or other cross-mixing spraying methods.

[0027] Third, using solid lithium powder instead of molten liquid lithium reduces energy consumption in the preparation process and improves safety.

[0028] Fourth, after drying, two-dimensional materials can adhere tightly to the surface of lithium powder, forming a closed space. At the same time, due to its shape, lithium powder also has some gaps, providing buffer space for volume expansion. Currently, lithium powder is available in two forms: spherical and irregularly shaped flakes. Using spherical powder can provide more buffer space, while using flake powder can provide a denser structure.

[0029] Fifth, functional particles can also be loaded onto the surface of two-dimensional materials, further improving the practicality of lithium anodes.

[0030] Sixth, this invention can be produced on a large scale, quickly and continuously, and at low temperatures; the resulting composite film has a surface protective layer that can be temporarily stable in air, making it easy to cut and apply directly. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of the dual-axis rotary spraying device used in this invention. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0033] Unless otherwise specified, the experimental methods used in the embodiments of this application are all conventional methods.

[0034] In the following examples and comparative examples, unless otherwise specified, all raw materials can be prepared, synthesized, or commercially available by conventional methods.

[0035] Example 1

[0036] Figure 1 This is a simplified diagram of the dual-axis rotary spraying device used in this embodiment, including a rotating shaft 1, a spraying container A2 connected to the rotating shaft 1, a second spraying container B3, a first nozzle 4 disposed on the spraying container A2, a second nozzle 5 disposed on the spraying container B3, a base plate 6 located below the first nozzle 4 and the second nozzle 5, and a heating device 7 located below the base plate 6. An electrode substrate 8 is placed on the base plate 6. The rotating shaft 1 can move left and right along with the first nozzle 4 and the second nozzle 5 (the rotating shaft 1 is connected to a left and right moving mechanism, not shown in the figure), and the electrode substrate 8 can move left and right (driven by another left and right moving mechanism, not shown in the figure).

[0037] This embodiment provides a method for large-scale preparation of ultrathin lithium anodes, which include raw materials such as graphene, lithium powder, lithiophilic materials, and lithium dendrite-resistant particles. The specific steps include:

[0038] First, graphene and polyethylene oxide were added to DMC at a mass ratio of 10:1 to graphene at a mass ratio of 1:50000, and ultrasonically stirred for 1 hour (ultrasonic rod, ultrasonic frequency 40 kHz, power 600 W, the same below). Finally, tin oxide nanoparticles (tin oxide has lithiophilic and anti-lithium dendrite effects) were added at a mass ratio of 5:1 to graphene, and ultrasonically stirred for 1 hour to form the first dispersion. Then, lithium powder at a mass ratio of 2:1 to graphene was added to the second portion of DMC and ultrasonically stirred for 1 hour to form the second dispersion.

[0039] In the second step, the two dispersions prepared in step 1 are continuously added at low flow rates to spray container A and spray container B, respectively, while spraying at a flow rate of 1 ml / min. The rotation speed is 300 rpm, the nozzle moving speed is 10 mm / min, the substrate moving speed is 10 mm / min, the substrate drying temperature is 80°C, and the air pressure inside the spray chamber is 100 Pa. Spraying is carried out for 1 hour.

[0040] The third step involves preparing a solution of antimony fluoride and DMC at a ratio of 1:50, ultrasonically stirring for 1 hour, and then adding it to the third spraying container to spray the film prepared in step 2. The spraying rate is 2 ml / min, the rotation speed is 300 rpm, the spraying time is 0.5 hours, the substrate drying temperature is 80℃, and the air pressure inside the spraying chamber is 100 Pa.

[0041] The fourth step is to roll the dried membrane material under a pressure of 1 MPa.

[0042] In this embodiment, the lithium powder used is lithium powder prepared by the emulsion method.

[0043] The film thickness prepared in this embodiment is approximately 3.2 micrometers, the specific capacity of the negative electrode material is 1386 mAh / g, the first-stage efficiency is 90.5%, and the cycle life of the positive electrode LFP at 0.5C is 772 cycles.

[0044] Example 2

[0045] This embodiment provides a method for large-scale preparation of ultrathin lithium anodes, which include raw materials such as graphene, lithium powder, and lithiophilic materials, and specifically includes the following steps:

[0046] First, graphene and polyethylene oxide were added to DMC at a mass ratio of 10:1 to 1:50000 (the mass ratio of graphene to DMC), and ultrasonically stirred for 1 hour (ultrasonic rod, ultrasonic frequency 40 kHz, power 600 W, the same below). Finally, tin oxide nanoparticles at a mass ratio of 5:1 to graphene were added, and ultrasonically stirred for 1 hour to form the first dispersion. Then, lithium powder at a mass ratio of 2:1 to graphene was added to the DMC and ultrasonically stirred for 1 hour to form the second dispersion.

[0047] In the second step, the two dispersions prepared in step 1 are continuously added to spray containers A and B at low flow rates, respectively, while spraying at a flow rate of 1 ml / min. The rotation speed is 300 rpm, the nozzle moving speed is 10 mm / min, the substrate moving speed is 10 mm / min, the substrate drying temperature is 80°C, and the air pressure in the spray chamber is 100 Pa. Spraying is carried out for 1 hour.

[0048] The third step is to roll the dried membrane material under a pressure of 1 MPa.

[0049] The lithium powder used in this embodiment is prepared by vacuum distillation.

[0050] The film thickness prepared in this embodiment is approximately 2.8 micrometers, the specific capacity of the negative electrode material is 1386 mAh / g, the first-stage efficiency is 89.5%, and the cycle life of the positive electrode LFP at 0.5C is 479 cycles.

[0051] Example 3

[0052] This comparative example provides a method for large-scale preparation of ultrathin lithium anodes. The lithium anode comprises graphene, lithium powder, and other raw materials, with the tin oxide nanoparticles removed from the first step of Example 2. The lithium powder is prepared by ultrasonic crushing. The rest is the same as in Example 2 and will not be repeated.

[0053] The film thickness prepared in this example is approximately 2.7 micrometers, the specific capacity of the negative electrode material is 1386 mAh / g, the first-stage efficiency is 87.3%, and the cycle life of the positive electrode LFP at 0.5C is 435 cycles.

[0054] Example 4

[0055] This embodiment provides a method for large-scale preparation of ultrathin lithium anodes, which include MXene (Ti2CT). x Raw materials include black scale, lithium powder, lithium-affinity substances, and anti-lithium dendrite particles, using MXene (Ti2CT). x The lithium powder used is a substitute for graphene, prepared by mechanical pulverization. The rest is the same as in Example 1 and will not be repeated here.

[0056] The film thickness prepared in this embodiment is approximately 3.2 micrometers, the specific capacity of the negative electrode material is 1386 mAh / g, the first-stage efficiency is 88.9%, and the cycle life of the positive electrode LFP at 0.5C is 612 cycles.

[0057] Example 5

[0058] This comparative example provides a method for large-scale preparation of ultrathin lithium anodes. The lithium anode comprises raw materials such as graphene, lithium powder, tin oxide nanoparticles, and anti-lithium dendrite particles, except for the polyethylene oxide used in the first step of Example 1. The lithium powder is prepared by chemical deposition. The rest is the same as in Example 1 and will not be repeated.

[0059] The film prepared in this example has a thickness of approximately 2.7 micrometers, a specific capacity of 1386 mAh / g for the negative electrode material, an initial efficiency of 88.2%, and a cycle life of 478 cycles for the positive electrode LFP at 0.5C.

[0060] Example 6

[0061] This comparative example provides a method for large-scale preparation of ultrathin lithium anodes, which include raw materials such as graphene, lithium powder, tin oxide nanoparticles, and anti-lithium dendrite particles, and specifically includes the following steps:

[0062] First, graphene and polyethylene oxide were added to DMC at a mass ratio of 10:1 to graphene at a mass ratio of 1:50000, and ultrasonically stirred for 1 hour (ultrasonic rod, ultrasonic frequency 40 kHz, power 600 W, the same below). Finally, tin oxide nanoparticles at a mass ratio of 5:1 to graphene were added, and ultrasonically stirred for 1 hour to form the first dispersion. Then, lithium powder at a mass ratio of 2:1 to graphene was added to the second portion of DMC and ultrasonically stirred for 1 hour to form the second dispersion.

[0063] The second step involves mixing the two dispersions prepared in step 1 at a 1:1 ratio, and adding antimony fluoride. The mass ratio of antimony fluoride to the mixed DMC is 1:50. The mixture is ultrasonically stirred for 1 hour to form a mixed solution. The mixed solution is then placed on a scraper and uniformly coated into a film with a coating thickness of 30 μm at a coating temperature of 25 degrees Celsius. The scraper is then dried to obtain a thin film at a drying temperature of 80 degrees Celsius.

[0064] The third step is to roll the dried membrane material under a pressure of 1 MPa.

[0065] The film thickness prepared in this embodiment is approximately 4.8 micrometers, the specific capacity of the negative electrode material is 1386 mAh / g, the first-stage efficiency is 78.3%, and the cycle life of the positive electrode LFP at 0.5C is 494 cycles.

[0066] Example 7

[0067] The rotation speed in steps two and three of Example 1 is modified to 5 rpm, and the rest is the same as in Example 1, so it will not be described again.

[0068] The film thickness prepared in this embodiment is approximately 3.9 micrometers, the specific capacity of the negative electrode material is 1386 mAh / g, the first-stage efficiency is 75.3%, and the cycle life of the positive electrode LFP at 0.5C is 378 cycles.

[0069] Example 8

[0070] The rotation speed in steps two and three of Example 1 is modified to 2000 rpm. The rest is the same as in Example 1 and will not be repeated.

[0071] The film thickness prepared in this embodiment is approximately 5.9 micrometers, the specific capacity of the negative electrode material is 1386 mAh / g, the first-stage efficiency is 86.3%, and the cycle life of the positive electrode LFP at 0.5C is 571 cycles.

[0072] Example 9

[0073] The mass ratio of graphene to DMC in the first step of Example 1 is modified to 1:5000. The rest is the same as in Example 1 and will not be repeated.

[0074] The film thickness prepared in this embodiment is approximately 46.3 micrometers, the specific capacity of the negative electrode material is 1386 mAh / g, the first-stage efficiency is 87.1%, and the cycle life of the positive electrode LFP at 0.5C is 595 cycles.

[0075] It is evident that the lithium anode in Example 1, after adding lithiophilic materials and anti-lithium dendrite particles, yielded relatively optimal test data. The reduced initial efficiency in Examples 2 and 3 is due to the need to consume lithium anode material to form an additional SEI layer, and the reduced cycle life reflects the decreased stability of the anode after the absence of the anti-lithium dendrite layer and lithiophilic material. Example 4, using a combination of MXene and black scale materials to replace graphene, also yielded an ultrathin lithium anode, but its performance was slightly inferior to that of Example 1. Example 5, compared to Example 1, removed the dispersant, resulting in a film with poor performance. Example 6, using a blade coating method instead of biaxial rotary spraying, resulted in a film with poor performance. In Example 7, adjusting the spraying speed to the lower limit reduced the uniformity of the film, leading to a decrease in performance. In Example 8, adjusting the spraying speed to the upper limit resulted in a film with better quality. In Example 9, achieving a film thickness of 46 micrometers yielded good performance.

[0076] Based on the disclosure and teachings of the foregoing specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the present invention should also fall within the protection scope of the claims of the present invention. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on the present invention.

Claims

1. A method for large-scale preparation of ultrathin lithium anodes, characterized in that, Includes the following steps: The first step is to uniformly disperse lithium powder and two-dimensional materials in solvents with similar boiling points or in the same solvent to form lithium powder dispersion and two-dimensional material dispersion, respectively. The second step involves cross-mixing the two-dimensional material dispersion and the lithium powder dispersion and coating them onto the substrate to obtain a lithium powder-two-dimensional material composite film. The third step is to spin-spray a layer of anti-lithium dendrite material dispersion or lithium-affinity material dispersion onto the surface of the lithium powder-two-dimensional material composite film. The fourth step involves drying the electrode to remove the solution and then rolling the film to obtain an ultrathin lithium anode. The anti-lithium dendrite material includes one of fluorides, oxides, and polymers. The fluoride is at least one of lithium fluoride, tin fluoride, antimony fluoride, aluminum fluoride, zinc fluoride, zirconium fluoride, copper fluoride, bismuth fluoride, silver fluoride, and manganese fluoride. The oxide is at least one of lithium oxide, tin oxide, antimony oxide, aluminum oxide, zinc oxide, zirconium oxide, copper oxide, bismuth oxide, silver oxide, and manganese oxide. The polymer is at least one of PEO, PAA, PVDF-HFP, PAN, PVC, and PMMA. The lithiophilic materials are oxides, metal powders, and other compounds with functional groups that can bind to lithium metal. The oxides are at least one of lithium oxide, tin oxide, antimony oxide, aluminum oxide, zinc oxide, zirconium oxide, copper oxide, bismuth oxide, silver oxide, and cobalt oxide. The metal powders are at least one of tin, copper, zinc, zirconium, silver, indium, gallium, and aluminum. The other compounds with functional groups that can bind to lithium metal are at least one of organic macromolecules, polymers with hydroxyl or ketone functional groups, nitrogen, sulfur, or phosphorus doped carbon materials, 1,3,5-tris(p-formylphenyl)benzene-covalent organic framework (TFPB-COF), and metal-organic framework (MOF).

2. The method for large-scale preparation of ultrathin lithium anodes according to claim 1, characterized in that, The two-dimensional material is at least one of graphene and MXene, or a mixture of two-dimensional non-conductive and conductive materials. The two-dimensional conductive material includes at least one of graphene, MXene, and two-dimensional polyaniline (2DPANI), and the two-dimensional non-conductive material includes at least one of molybdenum sulfide, black scale, gadolinium oxide (Gd2O5), and boron nitride (BN). MXene is specifically Ti2CT. x TiNbCT x Ti3CN x T x Ta4C3T x、 Nb2CT x V2CT x Nb4C3T x Mo2CT x 、(Nb 0.8 Ti 0.2 )4C3T x、 (Nb 0.8 Zr 0.2 )4C3T x、 Zr3C2T x and Hf3C2T x At least one of them, wherein T x The terminal of the surface is a combination of various functional groups such as OH, O, F, Cl, and Br.

3. The method for large-scale preparation of ultrathin lithium anodes according to claim 1, characterized in that: The solvent mentioned in the first step is at least one of lipids, ethers, N-methylpyrrolidone, vegetable oils, and alkanes; wherein the lipids are at least one of ethylene carbonate (EC), dimethyl carbonate (DMC), and diethyl carbonate (DEC), the ethers are dimethyl ether (DME), and the alkanes are at least one of pentane, hexane, heptane, octane, nonane, decane, or their isomers.

4. The method for large-scale preparation of ultrathin lithium anodes according to claim 1, characterized in that: The two-dimensional material dispersion also includes a dispersant, which includes polyvinylpyrrolidone (PVP), sodium dodecylbenzene sulfonate (SDBS), sodium lignosulfonate (SLS), polyvinyl alcohol (PVA), polyethylene oxide, polyacrylic acid, polymethacrylic acid, and polyacrylamide.

5. The method for large-scale preparation of ultrathin lithium anodes according to claim 1, characterized in that: Lithium dendrite-resistant or lithium-affinity materials are preloaded onto two-dimensional materials, or sprayed simultaneously with lithium powder and two-dimensional materials through a third nozzle to form a film.

6. The method for large-scale preparation of ultrathin lithium anodes according to claim 1, characterized in that: The thickness of the lithium powder-two-dimensional material composite film is 1 micrometer-50 micrometers, the mass concentration of the two-dimensional material dispersion is 0.1-5%, the mass concentration of the lithium powder dispersion is 0.1-10%, the spraying time in the second step is 0.1-10 hours, the rotation speed is 5-2000 rpm, the drying temperature is 30-150℃, and the air pressure is 10 Pa to atmospheric pressure.

7. The method for large-scale preparation of ultrathin lithium anodes according to claim 1, characterized in that: Cross-mix coating is achieved through biaxial rotary spraying, or by scraping or rotary smearing to form a film.

8. The method for large-scale preparation of ultrathin lithium anodes according to claim 1, characterized in that: Lithium powder is prepared by emulsion method, vacuum distillation method, ultrasonic crushing method, mechanical pulverization method or chemical deposition method.

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