Alloy carbon-based interface layer composite negative electrode with high interface stability as well as preparation and application of alloy carbon-based interface layer composite negative electrode

Abstract

The invention relates to an alloy carbon-based interface layer composite negative electrode with high interface stability and a preparation method and application thereof.The alloy carbon-based interface layer composite negative electrode comprises a lithium-loving alloy and a three-dimensional mixed carbon-based interface framework layer arranged on the surface of the lithium-loving alloy, and the three-dimensional mixed carbon-based interface framework layer comprises a one-dimensional carbon fiber material and a zero-dimensional carbon particle material with the mass ratio being 1: 45-1: 4; according to the lithium-loving alloy, a lithium-loving layer is arranged on the surface of metal lithium, the lithium-loving layer accounts for 0.001 wt.%-20.0 wt.% of lithium metal, in the inert argon atmosphere, the three-dimensional mixed carbon-based interface framework layer and the pressed lithium-loving alloy are attached and rolled, and the carbon-based interface is modified to the surface of the lithium-loving alloy. Compared with the prior art, the preparation method has the advantages that huge volume change in negative electrode side long circulation can be slowed down, the problems of overgrowth of dendrites, loss of active lithium and the like are relieved, and the electrochemical performance and safety of the battery are improved.

Description

Technical Field

[0001] This invention relates to lithium batteries, and more particularly to an alloy carbon-based interface layer composite anode with high interface stability, its preparation method, and the battery thereof. Background Technology

[0002] Currently, research on lithium-based batteries suitable for large-scale electrochemical energy storage applications such as electric vehicles and smart grids is booming. Improving the energy density of lithium-based batteries has always been a pursuit of many researchers. Unfortunately, traditional graphite anodes cannot meet the high energy density requirements of future lithium-based battery applications. In contrast, lithium metal anodes offer advantages due to their higher theoretical specific capacity (3860 mAh g / g). -1 vs. Graphite 372mAh g -1 The lithium metal anode has become a research hotspot for the next generation of batteries due to its low redox potential (-3.04V vs. standard hydrogen electrode). However, lithium metal anodes have many technical problems when used: (1) The thermodynamic instability between lithium metal and electrolyte can easily lead to the formation of an unstable interface layer on the surface of lithium metal, resulting in serious side reactions and poor battery cycle performance; (2) The unstable anode interface can easily induce uneven deposition of lithium ions, leading to the generation of lithium dendrites and dead lithium. This will not only aggravate the loss of active lithium, but the presence of lithium dendrites may also puncture the battery separator, causing the positive and negative electrodes to contact and short-circuit, resulting in safety problems.

[0003] Therefore, researchers have proposed numerous strategies to address the interfacial instability on the lithium metal anode side, induce uniform lithium-ion deposition, and improve battery cycle performance.

[0004] Patent CN105845891B discloses a lithium metal anode with a double-layer structure. Through a three-dimensional current collector design, it reduces the local current density on the anode side, suppressing dendrite growth and stabilizing the lithium metal anode, thereby improving battery energy utilization and cycle life. It also guides uniform lithium nucleation. However, the overall fabrication process is complex and the production cost is high. Prestoring Lithium into Stable 3D Nickel Foam Host as Dendrite-Free Lithium Metal Anode, Adv Funct Mater. 2017; 27:1700348, discloses a method of hot-melting lithium metal into nickel foam to obtain a composite anode with a high specific surface area. However, this hot-melt preparation method is dangerous and complex, unsuitable for the fabrication of large-cell electrodes, and cannot meet the needs of practical applications. Hierarchically Bicontinuous Porous Copper as Advanced 3D Skeleton for Stable Lithium Storage, ACS ApplMater. Inter.2018;10:13552-13561 discloses a method to improve the plating / stripping behavior of lithium by growing highly porous structures on a copper foam substrate to achieve pore structure gradient. However, this method has limited effect on improving the long cycle life of high energy density lithium metal batteries, especially in the later stages of cycling, when the pore structure is prone to failure and inactive lithium accumulates on the surface.

[0005] Patent CN105870502A discloses an electrolyte additive and its application in improving the cycle life of lithium metal batteries. By screening the electrolyte formulation, a stable solid electrolyte interface layer is formed on the surface of lithium metal. This can suppress the formation of lithium dendrites on the surface of the lithium metal anode, improve battery safety, protect lithium metal from electrolyte corrosion, and improve the utilization rate and cycle stability of lithium metal batteries with lithium metal as the anode. (Self-assembled monolayers direct a LiF-rich interphase toward long-life lithiummetalbatteries, Science. 2022; 375:739-745) This design of self-assembled monolayers accelerates the degradation kinetics of carbon-fluorine bond cleavage in trifluoromethanesulfonylimide, thereby generating a more stable lithium fluoride-rich solid electrolyte interface layer. (Ultralong-life lithium metal batteries enabled by decorating robust hybrid interphases on 3D layered frameworks, Chin Chem) Lett. 2023; 34:107602. This paper describes how a stable solid electrolyte interface layer rich in inorganic components is generated during battery cycling by pre-constructing an artificial interface rich in halogen compounds at the lithium metal anode interface. Regarding strategies for forming a stable solid electrolyte interface layer, including the aforementioned literature, researchers mainly focus on the electrolyte, aiming to generate a solid electrolyte interface layer rich in inorganic components. However, components such as lithium fluoride are difficult to degrade, putting pressure on the sustainable development of the ecological environment.

[0006] Currently, the construction of three-dimensional conductive framework networks based on metal current collectors is quite complex and prone to failure after long-term cycling. Methods involving electrolyte component control and artificial construction of solid electrolyte interface layers contradict the call for environmentally friendly development. Summary of the Invention

[0007] The purpose of this invention is to overcome the defects of the prior art by providing an alloy carbon-based interface layer composite anode with high interface stability, its preparation method and application. Based on the conductive carbon materials commonly used in the battery field, a three-dimensional conductive network is constructed and modified on the surface of the modified lithium-loving alloy to alleviate the volume change and dendrite growth problems on the anode side of lithium metal batteries. The materials are inexpensive and readily available, and the preparation method is simple and effective, which meets the requirements of green development.

[0008] The objective of this invention can be achieved through the following technical solution: a composite anode with a high interface stability based on an alloy carbon-based interface layer, comprising a lithiophilic alloy and a three-dimensional hybrid carbon-based interface framework layer disposed on its surface. The three-dimensional hybrid carbon-based interface framework layer comprises one-dimensional carbon fiber material and zero-dimensional carbon particle material in a mass ratio of 1:45 to 1:4. The lithiophilic alloy is a lithium metal with a lithiophilic layer disposed on its surface, and the lithiophilic layer accounts for 0.001 wt.% to 20.0 wt.% of the lithium metal.

[0009] Furthermore, the thickness of the three-dimensional hybrid carbon-based interface skeleton layer is 5–20 μm, wherein one-dimensional carbon fiber material constitutes the framework structure of the entire skeleton layer, and zero-dimensional carbon particle material fills the interior of the framework structure.

[0010] Furthermore, the one-dimensional carbon fiber material is one or more of multi-walled carbon nanotubes, single-walled carbon nanotubes, and carbon fibers.

[0011] The zero-dimensional carbon particle material is one or more of Super P, acetylene black, Ketjen black, mesophase carbon microspheres, and hard carbon.

[0012] Furthermore, the three-dimensional hybrid carbon-based interface framework layer is prepared by the following method:

[0013] One-dimensional carbon fiber material and zero-dimensional carbon particle material are physically mixed, ground, and vibrated. Polyvinylidene fluoride and N-methylpyrrolidone solution are added and mixed evenly. The resulting slurry is coated on the bright side of a copper foil and dried to obtain a three-dimensional hybrid carbon-based interface skeleton layer.

[0014] Furthermore, the amount of polyvinylidene fluoride added is 5.0 wt.%-20.0 wt.% of the total mass of the one-dimensional carbon fiber material and the zero-dimensional carbon particle material.

[0015] Furthermore, the water content of the dried three-dimensional mixed carbon-based interface framework layer is less than 1 ppm.

[0016] Furthermore, the lithium-loving alloy is prepared by the following method:

[0017] Lithophilic metal powder and polyvinylidene fluoride are added to a solvent, mixed evenly, and the resulting slurry is evenly coated on the bright surface of copper foil. After drying, a lithophilic coating is obtained.

[0018] A lithiophilic coating is pressed onto the surface of lithium metal, and the mixture is folded and pressed repeatedly to obtain a lithiophilic alloy.

[0019] Furthermore, the lithium-loving metal powder includes silver powder, zinc oxide powder, or aluminum powder;

[0020] The mass ratio of the lithium-loving metal powder to polyvinylidene fluoride is 9.5:0.5 to 8:2;

[0021] The moisture content in the dried lithiophilic coating is less than 1 ppm.

[0022] This invention also provides a method for preparing an alloy carbon-based interface layer composite negative electrode, comprising the following steps:

[0023] A carbon-based composite anode is prepared by physically bonding a three-dimensional hybrid carbon-based interface framework layer and a lithiophilic alloy, followed by roll forming to transfer the three-dimensional hybrid carbon-based interface framework layer to the surface of the lithiophilic alloy.

[0024] The present invention also provides an application of an alloy carbon-based interface layer composite anode, which is used to assemble lithium metal batteries, including coin cells and pouch cells.

[0025] The electrolyte system of the lithium metal battery includes a polymer solid system suitable for lithium metal batteries.

[0026] The positive electrode of the lithium metal battery cell includes any one of the following systems: lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, and sulfur.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. Unlike traditional artificial interface layers used to regulate the uniform deposition of lithium, this invention modifies the surface of a lithium metal anode with a three-dimensional carbon-based framework featuring a porous structure. This interface layer is composed of a mixture of one-dimensional carbon fiber material and zero-dimensional carbon particle material. The one-dimensional carbon fiber material forms the framework structure of the entire layer, while the zero-dimensional carbon particle material fills the framework structure to create suitable pore structures, thereby regulating the electronic and ionic conductivity of the carbon-based interface layer and enabling rapid migration of lithium ions within the carbon layer. Therefore, the carbon layer of this invention has high ionic conductivity and low electronic conductivity. Combined with the numerous deposition sites in the bottom alloy layer, it can regulate the uniform deposition of lithium across the carbon layer onto the alloy surface, mitigating the significant volume changes during long-term cycling on the anode side and alleviating problems such as dendrite growth and loss of active lithium.

[0029] 2. In this invention, due to the presence of the carbon-based interface layer, when the battery is subjected to high temperatures and the solid electrolyte interface is damaged, it can effectively isolate the electrolyte from further contact with lithium metal, avoid further exothermic reactions, and enable the lithium metal battery to have good safety performance.

[0030] 3. In terms of materials, compared with numerous interface layer designs and modification methods, this invention only uses inexpensive and readily available carbon materials and lithium-loving materials to design the interface layer and alloy anode, which will not cause damage to the environment and is in line with the concept of green development.

[0031] 4. In terms of experimental methods, the main experimental operations can be carried out at room temperature, the operation is relatively simple, some operations can be replaced by mechanization, and the commercialization prospects are broad. Attached Figure Description

[0032] Figure 1 These are optical images of the various carbon-based interface layers coated in Example 1.

[0033] Figure 2 This is an optical image of the silver coating interface layer in Example 1.

[0034] Figure 3 This is an optical image of carbon layer laminated onto the surface of lithium silver alloy in Example 1.

[0035] Figure 4 This refers to the cycling performance of the carbon-based interface layer in the Li-Cu half-cell in Example 2.

[0036] Figure 5 This is an optical image showing the successful regulation of lithium uniform deposition to the bottom of the carbon layer by the carbon-based interface layer in Example 2.

[0037] Figure 6 The cycling performance of the alloy carbon-based interface layer composite negative electrode in Example 3 in a full cell with high-load lithium nickel cobalt manganese oxide 523 as the positive electrode is shown. Detailed Implementation

[0038] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0039] This invention provides an alloy carbon-based interface layer composite anode, which is prepared by bonding and rolling a designed and coated carbon layer and a pressed alloy anode together in an inert argon atmosphere to modify the carbon-based interface onto the surface of the lithium-affinity alloy. Specifically, the method includes the following steps:

[0040] (1) Design of carbon-based interface layer: Carbon materials of different dimensions (one-dimensional carbon fiber materials and zero-dimensional carbon particle materials) are physically mixed, ground, and vibrated, with the mass ratio of one-dimensional carbon fiber materials to zero-dimensional carbon particle materials being 1:45 to 1:4. 10wt% of polyvinylidene fluoride and N-methylpyrrolidone solution (2.5ml per 100mg of material) are added to the physically mixed carbon materials and placed in a mixing tank for uniform mixing. The resulting slurry is then coated on the bright side of a copper foil. Figure 1 , Figure 2 The mixture was dried in a forced-air oven at 60°C for 6 hours, and then dried in a vacuum oven at 80°C for 12 hours to ensure that the water content in the resulting three-dimensional hybrid carbon-based interface framework layer was less than 1 ppm; the thickness of the three-dimensional hybrid carbon-based interface framework layer was 5-20 μm.

[0041] Among them, the types and characteristics of carbon materials are as follows: one-dimensional carbon fiber materials constitute the framework structure of the entire skeleton layer, including one or more of multi-walled carbon nanotubes, single-walled carbon nanotubes, and carbon fibers; zero-dimensional carbon particle materials fill the interior of the framework structure, adjust the conductivity of the entire carbon-based interface, and the pore structure of the three-dimensional skeleton, including one or more of Super P, acetylene black, Ketjen black, mesophase carbon microspheres, and hard carbon.

[0042] (2) Modification and preparation of lithium metal anode: A certain amount of lithium-loving metal powder (including: silver powder, zinc oxide powder, aluminum powder, etc., with aluminum powder preferably having a particle size of 50 nm; the lithium-loving metal powder accounts for 0.001 wt.% to 20.0 wt.% of lithium metal) and polyvinylidene fluoride are mixed by shaking at a mass ratio of 9:1. N-methylpyrrolidone solution (2.5 ml per 100 mg of material) is added and mixed evenly in a mixing tank. The resulting slurry is evenly coated on the bright surface of copper foil and dried in a forced-air oven at 60°C for 6 h. Then it is dried in a vacuum oven at 80°C for 12 h to ensure that the moisture content in the coating system is less than 1 ppm, and a lithium-loving coating with a thickness of 50 μm is obtained. The lithium-loving coating is pressed onto the lithium metal surface by a roller press, and the pressed composite material is folded from the center and repeatedly rolled multiple times, preferably 20 times, to form a lithium-loving alloy.

[0043] (3) Preparation of carbon-based composite negative electrode: In an inert argon atmosphere, the three-dimensional mixed carbon-based interface framework layer obtained in step (1) and the lithiophilic alloy obtained in step (2) are physically bonded together, and the three-dimensional mixed carbon-based interface framework layer is pressed onto the surface of the lithiophilic alloy by a roller press. Figure 3 A carbon-based composite anode was prepared by transferring a three-dimensional hybrid carbon-based interface framework layer to the alloy surface.

[0044] The above method modifies the surface of lithium metal anode with a three-dimensional carbon-based framework with a porous structure. The interface layer is composed of a mixture of one-dimensional carbon fiber material and zero-dimensional carbon particle material. The one-dimensional carbon fiber material constitutes the framework structure of the entire layer, and the zero-dimensional carbon particle material fills the framework structure to construct a suitable pore structure. This regulates the electronic conductivity and ionic conductivity of the carbon-based interface layer, enabling the rapid migration of lithium ions in the carbon layer.

[0045] This alloy-based carbon-based interface layer composite anode is used in lithium metal polymer solid-state battery systems. The large specific surface area of ​​the three-dimensional carbon-based framework interface layer can significantly reduce the local current density on the anode side and alleviate lithium dendrite growth. Simultaneously, the numerous suitable pore structures provide a complete pathway for lithium-ion diffusion, and the lithium alloy at the bottom of the carbon layer provides reliable sites for lithium nucleation and growth, achieving uniform lithium deposition at the bottom of the carbon layer and greatly reducing the loss of active lithium during long-term battery cycling. The alloy-based carbon-based interface layer composite anode can significantly improve the coulombic efficiency of lithium metal and the lifespan of the entire battery, showing promising application prospects.

[0046] The following detailed description is provided through specific embodiments. Unless otherwise specified, the raw materials and equipment involved in this invention are all commercially available and commonly used in the field.

[0047] Example 1:

[0048] Super P and multi-walled carbon nanotubes were coated using a wet process at a mass ratio of 9:1. Figure 1 A carbon-based interface layer was constructed. The specific process steps and conditions are as follows:

[0049] Carbon layer construction: Super P and multi-walled carbon nanotubes were physically mixed at a mass ratio of 9:1, ground, and vibrated. The total mass of carbon material was 400 mg. 10 wt% of polyvinylidene fluoride (PVDF), 40 mg, and 10 ml of N-methylpyrrolidone solution were added to the total mass of carbon material (i.e., the sum of the masses of Super P and multi-walled carbon nanotubes). The mixture was placed in a mixing tank and mixed evenly. The resulting slurry was coated on the bright side of a copper foil and dried in a forced-air oven at 60 °C for 6 h. Then, it was dried in a vacuum oven at 80 °C for 12 h to ensure that the water content in the resulting three-dimensional mixed carbon-based interface framework layer was less than 1 ppm. The thickness of the three-dimensional mixed carbon-based interface framework layer was 20 μm.

[0050] Example 2:

[0051] Super P and multi-walled carbon nanotubes were coated at a mass ratio of 4:1 using the same wet coating process as in Example 1. Figure 1 A carbon-based interface layer was constructed.

[0052] Comparative Example 1

[0053] A comparison was made using 20μm pure copper foil without carbon layer modification.

[0054] Performance Test 1:

[0055] To verify the role of the carbon-based interface layer, the carbon-based interface layers prepared in Examples 1 and 2, and the pure copper foil of Comparative Example 1 were used as positive electrodes and lithium metal was used as negative electrodes to assemble a half cell.

[0056] The test was conducted in a 1M LiTFSI / P (VEC-DPHA) polymer system. The specific test method was as follows: first, at 1 mA cm -2 Discharged at a current density for 1 hour, then at 1 mA cm⁻¹ -2 It is charged to 1V at a current density. The result is as follows. Figure 4 As shown, it can be seen that the half-cells of Examples 1 and 2, when tested at a current of 1 mA cm⁻¹, exhibit performance similar to those in Examples 1 and 2. -2 After 100 cycles, the coulombic efficiency remained above 97% and was stable, while the coulombic efficiency of Comparative Example 1 was below 93% and unstable in multiple cycle tests.

[0057] The results demonstrate that the carbon-based interface layers constructed in Examples 1 and 2 exhibit higher coulombic efficiency and stability compared to pure copper foil without carbon layer modification.

[0058] After 100 cycles, the carbon-based interface layer prepared in Example 1 was disassembled and observed. It was found that, compared to the initial state, a uniform lithium deposition (gray) was distributed at the bottom of the carbon layer. Verification of the product with ethanol showed that upon adding ethanol to the gray deposition, the gray deposition reacted violently immediately and disappeared rapidly, exposing a bright copper foil. Figure 5 The presence of carbon indicates that the sediment was consumed, verifying that it was lithium deposition, and demonstrating the feasibility of the carbon layer regulating lithium deposition behavior.

[0059] As can be seen, in the comparison of Examples 1, 2 and Comparative Example 1, different three-dimensional hybrid carbon-based interface layers all exhibit excellent cycle stability and can regulate the uniform deposition of lithium to the bottom of the carbon layer, highlighting the excellent kinetic performance of the three-dimensional hybrid carbon-based interface layer.

[0060] Example 3:

[0061] A composite anode with an alloy carbon-based interface layer, the specific process steps and conditions are as follows:

[0062] (1) Acetylene black and multi-walled carbon nanotubes were coated using the same wet process as in Example 1 at a mass ratio of 4:1. Figure 1 A carbon-based interface layer was constructed.

[0063] (2) Modification and preparation of lithium metal anode: 200 mg of silver powder with a particle size of 50 nm (the silver powder accounts for 10.0 wt.% of the lithium metal) and polyvinylidene fluoride were mixed by shaking at a mass ratio of 9:1. 5 ml of N-methylpyrrolidone solution was added and mixed evenly in a mixing tank. The resulting slurry was evenly coated on the bright surface of copper foil and dried in a forced-air oven at 60 °C for 6 h. Then it was dried in a vacuum oven at 80 °C for 12 h to ensure that the moisture content in the coating system was less than 1 ppm, and a lithiophilic coating with a thickness of 50 μm was obtained. The lithiophilic coating was pressed onto the lithium metal surface by a roller press, and the pressed composite material was folded from the center and repeatedly rolled 20 times to form a lithiophilic alloy.

[0064] (3) Preparation of carbon-based composite anode: In an inert argon atmosphere, the three-dimensional mixed carbon-based interface framework layer obtained in step (1) and the lithiophilic alloy obtained in step (2) are physically bonded together. The three-dimensional mixed carbon-based interface framework layer is pressed onto the surface of the lithiophilic alloy by a roller press. The three-dimensional mixed carbon-based interface framework layer is transferred to the alloy surface to obtain a carbon-based composite anode. Figure 6 (LiAg+AB&CNTs 20%).

[0065] Example 4:

[0066] Acetylene black and multi-walled carbon nanotubes were mixed in a mass ratio of 9:1, with zinc oxide powder as the lithium-loving metal powder, and the rest of the process was the same as in Example 3. A carbon-based composite anode was thus prepared. Figure 6 (LiAg+AB&CNTs 10%)

[0067] Example 5:

[0068] Super P and multi-walled carbon nanotubes were mixed in a mass ratio of 4:1, with silver powder as the lithium-loving metal powder, and the rest of the process was the same as in Example 4. A carbon-based composite anode was thus prepared. Figure 6 LiAg+SP&CNTs 20%

[0069] Comparative Example 2

[0070] Pure lithium metal without carbon layer modification and without lithium-philic material modification was used as the negative electrode. Figure 6 (Li).

[0071] Performance Test 2:

[0072] A full cell was assembled using the carbon-based alloy composite anode prepared in Examples 3-5 and the pure lithium metal from Comparative Example 2 as the anode, and a high-nickel ternary cathode as the cathode. Testing was conducted in a 1M LiTFSI / P(VEC-DPHA) 5wt% LiNO3 polymer system. The specific testing method was as follows: activation at 0.05C for 5 cycles, with an activation voltage range of 3.0-4.3V, followed by cycling at 0.05C, with a cycling voltage range of 2.8-4.3V. Figure 6 NCM523 in footnote: 19 mg / cm 2 ,0.05C,P(VEC-DPHA,LiNO3).

[0073] The results are as follows Figure 6 As shown, under the same test conditions, after 40 cycles, the discharge capacity and coulombic efficiency of the different carbon-based alloy composite anodes prepared in Examples 3-5 are all higher than those in Comparative Example 2, exhibiting superior overall electrochemical performance. Compared to pure lithium metal anodes, carbon-based alloy composite anodes show a stable increase in both battery capacity and coulombic efficiency.

[0074] The performance of the above embodiments and comparative examples is as follows:

[0075] Coulomb efficiency Discharge capacity Cyclic stability Example 3 All cycles are above 99% <![CDATA[40 cycles of 160 mAh g -1 > Stablize Example 4 All cycles are above 99% <![CDATA[40 cycles of 150 mAh g -1 > Relatively stable Example 5 All cycles are above 99% <![CDATA[36 cycles of 152 mAh g -1 > Relatively stable Comparative Example 2 The cycle is around 98%. <![CDATA[138 mAh g at 40 cycles -1 > Unstable

[0076] As can be seen, in the comparison between Examples 3-5 and Comparative Example 2, the different three-dimensional hybrid carbon-based interface alloy anodes all exhibited higher discharge capacity and higher and more stable coulombic efficiency, highlighting the excellent electrochemical performance of the composite anode.

[0077] Those skilled in the art should understand that this invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to this invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A composite negative electrode with an alloy carbon-based interface layer and high interface stability, characterized in that, The invention includes a lithiophilic alloy and a three-dimensional hybrid carbon-based interface framework layer disposed on its surface. The three-dimensional hybrid carbon-based interface framework layer comprises one-dimensional carbon fiber material and zero-dimensional carbon particle material in a mass ratio of 1:45 to 1:

4. The lithiophilic alloy is a lithium metal with a lithiophilic layer disposed on its surface, and the lithiophilic layer accounts for 0.001 wt.% to 20.0 wt.% of the lithium metal.

2. The alloy carbon-based interface layer composite negative electrode with high interface stability according to claim 1, characterized in that, The thickness of the three-dimensional hybrid carbon-based interface skeleton layer is 5-20 μm, wherein one-dimensional carbon fiber material constitutes the framework structure of the entire skeleton layer, and zero-dimensional carbon particle material fills the interior of the framework structure.

3. The alloy carbon-based interface layer composite negative electrode with high interface stability according to claim 1, characterized in that, The one-dimensional carbon fiber material mentioned above is one or more of multi-walled carbon nanotubes, single-walled carbon nanotubes, and carbon fibers. The zero-dimensional carbon particle material is one or more of Super P, acetylene black, Ketjen black, mesophase carbon microspheres, and hard carbon.

4. The alloy carbon-based interface layer composite negative electrode with high interface stability according to claim 1, characterized in that, The aforementioned three-dimensional hybrid carbon-based interface framework layer is prepared by the following method: One-dimensional carbon fiber material and zero-dimensional carbon particle material are physically mixed, ground, and vibrated. Polyvinylidene fluoride and N-methylpyrrolidone solution are added and mixed evenly. The resulting slurry is coated on the bright side of a copper foil and dried to obtain a three-dimensional hybrid carbon-based interface skeleton layer.

5. The alloy carbon-based interface layer composite negative electrode with high interface stability according to claim 4, characterized in that, The amount of polyvinylidene fluoride added is 5.0 wt.% to 20.0 wt.% of the total mass of one-dimensional carbon fiber material and zero-dimensional carbon particle material.

6. The alloy carbon-based interface layer composite negative electrode with high interface stability according to claim 4, characterized in that, The water content of the dried three-dimensional mixed carbon-based interface framework layer is less than 1 ppm.

7. The alloy carbon-based interface layer composite negative electrode with high interface stability according to claim 1, characterized in that, The aforementioned lithium-loving alloy is prepared by the following method: Lithophilic metal powder and polyvinylidene fluoride are added to a solvent, mixed evenly, and the resulting slurry is evenly coated on the bright surface of copper foil. After drying, a lithophilic coating is obtained. A lithiophilic coating is pressed onto the surface of lithium metal, and the mixture is folded and pressed repeatedly to obtain a lithiophilic alloy.

8. The alloy carbon-based interface layer composite negative electrode with high interface stability according to claim 7, characterized in that, The lithium-loving metal powder includes silver powder, zinc oxide powder, or aluminum powder; The mass ratio of the lithium-loving metal powder to polyvinylidene fluoride is 9.5:0.5 to 8:2; The moisture content in the dried lithiophilic coating is less than 1 ppm.

9. A method for preparing an alloy carbon-based interface layer composite negative electrode with high interface stability as described in any one of claims 1-8, characterized in that, Includes the following steps: A carbon-based composite anode is prepared by physically bonding a three-dimensional hybrid carbon-based interface framework layer and a lithiophilic alloy, followed by roll forming to transfer the three-dimensional hybrid carbon-based interface framework layer to the surface of the lithiophilic alloy.

10. An application of a composite anode with a high interface stability alloy carbon-based interface layer as described in any one of claims 1-8, characterized in that, The alloy carbon-based interface layer composite negative electrode is used to assemble lithium metal batteries.

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