A metal lithium negative electrode with a furan-based polyamide protective layer and a preparation method thereof

Abstract

The application discloses metal lithium negative electrode with furan-based polyamide protective layer and a preparation method thereof, and belongs to the technical field of batteries. 70 Al 30 The precursor is etched in an HCl solution, then is modified by ZnO, molten lithium is filled into the ZnO modified conductive framework, and the lithium metal is obtained; the lithium metal is immersed into a deionized water solution of FDA and SDS, then a TPC DCM solution is slowly added, and interfacial reaction is carried out; the lithium metal is immersed into a LiPF6 / EC solution containing GaP nanoparticles, and after heat treatment, the lithium metal modified by a functional composite layer is obtained; PVDF and F-NDs are uniformly mixed, and then are hot-pressed on the lithium metal modified by the functional composite layer, so that the metal lithium negative electrode with the furan-based polyamide protective layer is obtained. The multi-layered diaphragm cooperatively improves the ion transmission performance and the stability of the interfacial SEI film, so that the side reaction is effectively inhibited, and the electrochemical performance of the metal lithium negative electrode is improved.

Description

Technical Field

[0001] This invention belongs to the field of battery technology, specifically relating to a lithium metal anode with a furan-based polyamide protective layer and its preparation method. Background Technology

[0002] Lithium metal anodes are considered ideal battery anode materials due to their high theoretical specific capacity and low electrochemical potential, especially in applications such as high-performance lithium-ion batteries, lithium-sulfur batteries, and lithium-air batteries. However, during charging and discharging, lithium metal forms dendrites, and lithium continues to react with the electrolyte, consuming active lithium and forming an unstable SEI film. This not only reduces the coulombic efficiency of the battery but may also increase the risk of short circuits, thus limiting its widespread application.

[0003] To overcome these problems, researchers have developed various strategies to stabilize the surface of lithium metal anodes, including the use of electrolyte additives, artificial solid electrolyte interphase (SEI) layers, and physical barriers. Among these, constructing a protective layer is one of the effective ways to improve the cycle stability and safety of lithium metal anodes. A novel lithium metal anode with a furanyl polyamide protective layer is developed based on this approach.

[0004] Patent application CN 119170744 A discloses a negative electrode sheet, its preparation method, and a secondary battery. The negative electrode sheet includes: a negative current collector; a first active material layer disposed on at least one side surface of the negative current collector; and a second active material layer disposed on the surface of the first active material layer away from the negative current collector. The first active material layer includes a first active material coated with a first modified polymer, and the second active material layer includes a second active material coated with a second modified polymer. One of the first and second modified polymers includes at least a furan group, and the other includes at least a maleimide group. This application claims to provide a negative electrode sheet that utilizes the DA reaction between furan and maleimide to form self-healing polymer molecules, restoring interlayer peeling force in the later stages of cycling, reducing coating peeling, and improving cycle capacity retention. However, the DA reaction requires a high temperature to trigger, but the actual operating temperature of the battery is usually room temperature, which may lead to low repair efficiency. In addition, it is necessary to synthesize two modified polymers separately, coat the active material stepwise, and apply a double-layer coating, which increases production costs and yield risks, increases process complexity, and is not conducive to large-scale production. Summary of the Invention

[0005] The purpose of this invention is to provide a lithium metal anode with a furanyl polyamide protective layer and its preparation method, so as to improve the electrochemical performance of the lithium metal anode.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A method for preparing a lithium metal anode with a furanyl polyamide protective layer includes the following steps:

[0008] S1, Cu 70 Al 30 The precursor was etched in HCl solution to obtain a porous copper-aluminum framework; the porous copper-aluminum framework was placed in a reaction solution of Zn(NO3)2 and HMTA (hexamethylenetetramine) and heated to obtain a ZnO-modified conductive framework; molten lithium was poured into the ZnO-modified conductive framework to obtain lithium metal.

[0009] S2. Lithium metal is immersed in a deionized aqueous solution of FDA (furandiamine) and SDS (sodium dodecyl sulfate), and then TPC (terephthaloyl chloride) in DCM (dichloromethane) solution is slowly added to allow for interfacial reaction; after immersion in a LiPF6 / EC solution containing GaP nanoparticles and heat treatment, lithium metal modified with a functional composite layer is obtained.

[0010] S3. Mix PVDF (polyvinylidene fluoride) and F-NDs (fluorinated nanodiamonds) to obtain a slurry. Apply the slurry to lithium metal modified with a functional composite layer by hot pressing to obtain a lithium metal anode with a furan-based polyamide protective layer.

[0011] Furthermore, the concentration of the HCl solution is 0.5-0.8M; the etching is performed at a voltage of 3-4V for 30-60 minutes.

[0012] Furthermore, the concentration of Zn(NO3)2 in the Zn(NO3)2 and HMTA reaction solution is 0.03-0.06M, and the concentration of HMTA is 0.03-0.06M.

[0013] Furthermore, the heating reaction is carried out at 80-90°C for 3-4 hours.

[0014] Furthermore, the weight ratio of FDA, SDS and deionized water is (1.5-2.5):(0.5-1.5):(100-120).

[0015] Furthermore, the weight ratio of TPC to DCM is (0.3-0.7):(100-110).

[0016] Furthermore, the interfacial reaction is carried out at the interface between the deionized aqueous solution and the DCM solution for 2-4 minutes.

[0017] Furthermore, the weight ratio of the GaP nanoparticles to the LiPF6 / EC solution is (3-8):100; the volume ratio of LiPF6 to EC in the LiPF6 / EC solution is (0.8-1):(0.8-1).

[0018] Furthermore, the heat treatment is performed at 50-60°C for 30-60 minutes.

[0019] Furthermore, the mass ratio of the PVDF to F-NDs is (8-9):(1-2).

[0020] Furthermore, the hot-press coating involves uniformly coating a slurry onto a polyimide-based film, then hot-pressing the side of the polyimide-based film coated with the slurry onto a lithium metal substrate modified with a functional composite layer, and finally peeling off the polyimide-based film after cooling. The hot pressing is performed at 70-80°C and 0.5-0.6 MPa.

[0021] A lithium metal anode with a furanyl polyamide protective layer is prepared according to the above-described method for preparing lithium metal anodes.

[0022] The beneficial effects of this invention are:

[0023] (1) This invention uses Cu 70 Al 30 A precursor was electrochemically etched in HCl solution to construct a hierarchical porous copper-aluminum framework. Subsequent hydrothermal modification of the framework surface with ZnO significantly improved the specific surface area of ​​the conductive framework and the uniformity of lithium-ion deposition. Injecting molten lithium into this ZnO-modified three-dimensional framework not only effectively mitigated volume changes during lithium deposition / stripping but also physically suppressed lithium dendrites, thereby improving the structural stability and cycle life of the lithium metal anode.

[0024] (2) This invention generates a furan-based polyamide protective layer on the lithium metal surface through interfacial polymerization. The furan rings and amide bonds impart excellent mechanical strength and thermal stability to the coating, enhancing interfacial stability. Simultaneously, GaP nanoparticles are introduced, and after heat treatment in a LiPF6 / EC electrolyte system, Li3PO4 / Li x Ga composite interface layers synergistically enhance ion transport performance and the stability of the interface SEI film, thereby effectively suppressing side reactions and improving battery coulombic efficiency and safety.

[0025] (3) In this invention, PVDF slurry is coated onto a polyimide base film and hot-pressed to transfer it to the lithium metal surface. During the peeling process of the base film, F-NDs are directionally enriched, which can not only effectively prevent dendrite growth caused by electron leakage, but also enhance the mechanical strength and electrolyte corrosion resistance of the entire protection system. In addition, the close adhesion between the coating and the furan-based polyamide protective layer optimizes the electrode / electrolyte interface contact, reduces the interface impedance, homogenizes the lithium ion flow, suppresses local polarization, and achieves a synergistic improvement in high coulombic efficiency and long cycle life. Detailed Implementation

[0026] The specific embodiments of the present invention will be described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0027] Example 1

[0028] This embodiment provides a lithium metal anode with a furanyl polyamide protective layer, which is prepared through the following steps:

[0029] S1, Cu 70 Al 30 The precursor was placed in a 0.5M HCl solution and etched at 4V for 30 min to obtain a porous copper-aluminum framework; the porous copper-aluminum framework was placed in a 0.05M Zn(NO3)2 and 0.05M MTA reaction solution and reacted at 90℃ for 3 h to obtain a ZnO-modified conductive framework; molten lithium was poured into the ZnO-modified conductive framework to obtain lithium metal;

[0030] S2. Lithium metal is immersed in a deionized aqueous solution containing 2 wt% FDA and 1 wt% SDS, and then 0.5 wt% TPC DCM solution is slowly added. The reaction is carried out at the interface between the deionized aqueous solution and the DCM solution for 3 min. The lithium metal is then immersed in a LiPF6 / EC solution containing 5 wt% GaP nanoparticles (LiPF6 and EC volume ratio is 1:1) and heat-treated at 60℃ for 40 min to initiate an interfacial reaction to generate a Li3PO4 / LixGa composite, thus obtaining lithium metal modified with a functional composite layer.

[0031] S3. Mix 9 parts by weight of PVDF and 1 part by weight of F-NDs to obtain a slurry. Coat the slurry evenly on a polyimide-based film. Bond the side of the polyimide-based film coated with the slurry to the lithium metal modified with the functional composite layer. Hot press at 80°C and 0.5MPa. After cooling, peel off the polyimide-based film to obtain a lithium metal anode with a furanyl polyamide protective layer.

[0032] Example 2

[0033] The difference between this embodiment and Embodiment 1 is that the ratio of PVDF and F-NDs is adjusted. The specific implementation steps are as follows:

[0034] S1, Cu 70 Al 30 The precursor was placed in a 0.5M HCl solution and etched at 4V for 30 min to obtain a porous copper-aluminum framework; the porous copper-aluminum framework was placed in a 0.05M Zn(NO3)2 and 0.05M MTA reaction solution and reacted at 90℃ for 3 h to obtain a ZnO-modified conductive framework; molten lithium was poured into the ZnO-modified conductive framework to obtain lithium metal;

[0035] S2. Lithium metal is immersed in a deionized aqueous solution containing 2 wt% FDA and 1 wt% SDS, and then 0.5 wt% TPC DCM solution is slowly added. The reaction is carried out at the interface between the deionized aqueous solution and the DCM solution for 3 min. The lithium metal is then immersed in a LiPF6 / EC solution containing 5 wt% GaP nanoparticles (LiPF6 and EC volume ratio is 1:1) and heat-treated at 60℃ for 40 min to initiate an interfacial reaction to generate a Li3PO4 / LixGa composite, thus obtaining lithium metal modified with a functional composite layer.

[0036] S3. Mix 8 parts by weight of PVDF and 2 parts by weight of F-NDs to obtain a slurry. Coat the slurry evenly on a polyimide-based film. Bond the side of the polyimide-based film coated with the slurry to the lithium metal modified with the functional composite layer. Hot press at 75°C and 0.6 MPa. After cooling, peel off the polyimide-based film to obtain a lithium metal anode with a furanyl polyamide protective layer.

[0037] The remaining raw materials and preparation process are the same as in Example 1.

[0038] Example 3

[0039] Compared with Example 1, this embodiment differs in that the amount of GaP nanoparticles is increased, and the other components are adjusted accordingly. The specific implementation steps are as follows:

[0040] S1, Cu 70 Al 30 The precursor was placed in a 0.5M HCl solution and etched at 4V for 30 min to obtain a porous copper-aluminum framework; the porous copper-aluminum framework was placed in a 0.05M Zn(NO3)2 and 0.05M MTA reaction solution and reacted at 90℃ for 3 h to obtain a ZnO-modified conductive framework; molten lithium was poured into the ZnO-modified conductive framework to obtain lithium metal;

[0041] S2. Lithium metal is immersed in a deionized aqueous solution containing 2 wt% FDA and 1 wt% SDS, and then 0.5 wt% TPC DCM solution is slowly added. The reaction is carried out at the interface between the deionized aqueous solution and the DCM solution for 3 min. The lithium metal is then immersed in a LiPF6 / EC solution containing 7 wt% GaP nanoparticles (LiPF6 to EC volume ratio of 1:0.8) and heat-treated at 60℃ for 50 min to initiate an interfacial reaction to generate a Li3PO4 / LixGa composite, thus obtaining lithium metal modified with a functional composite layer.

[0042] S3. Mix 9 parts by weight of PVDF and 1 part by weight of F-NDs to obtain a slurry. Coat the slurry evenly on a polyimide-based film. Bond the side of the polyimide-based film coated with the slurry to the lithium metal modified with the functional composite layer. Hot press at 80°C and 0.5MPa. After cooling, peel off the polyimide-based film to obtain a lithium metal anode with a furanyl polyamide protective layer.

[0043] The remaining raw materials and preparation process are the same as in Example 1.

[0044] Example 4

[0045] Compared with Example 1, this embodiment differs in that the amount of GaP nanoparticles is reduced, and the remaining components are adjusted accordingly. The specific implementation steps are as follows:

[0046] S1, Cu 70 Al 30 The precursor was placed in a 0.5M HCl solution and etched at 4V for 30 min to obtain a porous copper-aluminum framework; the porous copper-aluminum framework was placed in a 0.05M Zn(NO3)2 and 0.05M MTA reaction solution and reacted at 90℃ for 3 h to obtain a ZnO-modified conductive framework; molten lithium was poured into the ZnO-modified conductive framework to obtain lithium metal;

[0047] S2. Lithium metal is immersed in a deionized aqueous solution containing 2 wt% FDA and 1 wt% SDS, and then a DCM solution containing 0.5 wt% TPC is slowly added. The reaction is carried out at the interface between the deionized aqueous solution and the DCM solution for 3 min. The lithium metal is then immersed in a LiPF6 / EC solution containing 3 wt% GaP nanoparticles (LiPF6 and EC volume ratio is 1:1) and heat-treated at 50 °C for 60 min to initiate an interfacial reaction to generate a Li3PO4 / LixGa composite, thus obtaining lithium metal modified with a functional composite layer.

[0048] S3. Mix 9 parts by weight of PVDF and 1 part by weight of F-NDs to obtain a slurry. Coat the slurry evenly on a polyimide-based film. Bond the side of the polyimide-based film coated with the slurry to the lithium metal modified with the functional composite layer. Hot press at 80°C and 0.5MPa. After cooling, peel off the polyimide-based film to obtain a lithium metal anode with a furanyl polyamide protective layer.

[0049] The remaining raw materials and preparation process are the same as in Example 1.

[0050] Example 5

[0051] The difference between this embodiment and Example 1 is that the dosages of FDA and TPC are adjusted, and the remaining components are adjusted accordingly. The specific implementation steps are as follows:

[0052] S1, Cu70 Al 30 The precursor was placed in a 0.5M HCl solution and etched at 4V for 30 min to obtain a porous copper-aluminum framework; the porous copper-aluminum framework was placed in a 0.05M Zn(NO3)2 and 0.05M MTA reaction solution and reacted at 90℃ for 3 h to obtain a ZnO-modified conductive framework; molten lithium was poured into the ZnO-modified conductive framework to obtain lithium metal;

[0053] S2. Lithium metal is immersed in a deionized aqueous solution containing 2.5 wt% FDA and 1.5 wt% SDS, and then a DCM solution containing 0.7 wt% TPC is slowly added. The reaction is carried out at the interface between the deionized aqueous solution and the DCM solution for 4 min. The lithium metal is then immersed in a LiPF6 / EC solution containing 5 wt% GaP nanoparticles (LiPF6 and EC volume ratio is 1:1) and heat-treated at 60 °C for 40 min to initiate an interfacial reaction to generate a Li3PO4 / LixGa composite, thus obtaining lithium metal modified with a functional composite layer.

[0054] S3. Mix 9 parts by weight of PVDF and 1 part by weight of F-NDs to obtain a slurry. Coat the slurry evenly on a polyimide-based film. Bond the side of the polyimide-based film coated with the slurry to the lithium metal modified with the functional composite layer. Hot press at 80°C and 0.5MPa. After cooling, peel off the polyimide-based film to obtain a lithium metal anode with a furanyl polyamide protective layer.

[0055] The remaining raw materials and preparation process are the same as in Example 1.

[0056] Example 6

[0057] The difference between this embodiment and Example 1 is that the concentrations of Zn(NO3)2 and HMTA are adjusted, and the remaining components are adjusted accordingly. The specific implementation steps are as follows:

[0058] S1, Cu 70 Al 30 The precursor was placed in a 0.6 M HCl solution and etched at 4 V for 40 min to obtain a porous copper-aluminum framework; the porous copper-aluminum framework was placed in a reaction solution of 0.04 M Zn(NO3)2 and 0.05 M HMTA and reacted at 90 °C for 3 h to obtain a ZnO-modified conductive framework; molten lithium was poured into the ZnO-modified conductive framework to obtain lithium metal;

[0059] S2. Lithium metal is immersed in a deionized aqueous solution containing 2 wt% FDA and 1 wt% SDS, and then 0.5 wt% TPC DCM solution is slowly added. The reaction is carried out at the interface between the deionized aqueous solution and the DCM solution for 3 min. The lithium metal is then immersed in a LiPF6 / EC solution containing 5 wt% GaP nanoparticles (LiPF6 and EC volume ratio is 1:1) and heat-treated at 60℃ for 40 min to initiate an interfacial reaction to generate a Li3PO4 / LixGa composite, thus obtaining lithium metal modified with a functional composite layer.

[0060] S3. Mix 9 parts by weight of PVDF and 1 part by weight of F-NDs to obtain a slurry. Coat the slurry evenly on a polyimide-based film. Bond the side of the polyimide-based film coated with the slurry to the lithium metal modified with the functional composite layer. Hot press at 80°C and 0.5MPa. After cooling, peel off the polyimide-based film to obtain a lithium metal anode with a furanyl polyamide protective layer.

[0061] The remaining raw materials and preparation process are the same as in Example 1.

[0062] Comparative Example 1

[0063] The difference between this comparative example and Example 1 is that F-NDs modification is not performed. The specific implementation steps are as follows:

[0064] S1, Cu 70 Al 30 The precursor was placed in a 0.5M HCl solution and etched at 4V for 30 min to obtain a porous copper-aluminum framework; the porous copper-aluminum framework was placed in a 0.05M Zn(NO3)2 and 0.05M MTA reaction solution and reacted at 90℃ for 3 h to obtain a ZnO-modified conductive framework; molten lithium was poured into the ZnO-modified conductive framework to obtain lithium metal;

[0065] S2. Immerse lithium metal in a deionized aqueous solution containing 2wt% FDA and 1wt% SDS, then slowly add a DCM solution containing 0.5wt% TPC, and react at the interface between the deionized aqueous solution and the DCM solution for 3 min; immerse in a LiPF6 / EC solution containing 5wt% GaP nanoparticles (LiPF6 and EC volume ratio is 1:1), and heat treat at 60℃ for 40 min to initiate an interfacial reaction to generate a Li3PO4 / LixGa composite, thus obtaining a lithium metal anode.

[0066] The remaining raw materials and preparation process are the same as in Example 1.

[0067] Comparative Example 2

[0068] The difference between this comparative example and Example 1 is that no modification of the functional composite layer is performed. The specific implementation steps are as follows:

[0069] S1, Cu 70 Al 30 The precursor was placed in a 0.5M HCl solution and etched at 4V for 30 min to obtain a porous copper-aluminum framework; the porous copper-aluminum framework was placed in a 0.05M Zn(NO3)2 and 0.05M MTA reaction solution and reacted at 90℃ for 3 h to obtain a ZnO-modified conductive framework; molten lithium was poured into the ZnO-modified conductive framework to obtain lithium metal;

[0070] S2. Mix 9 parts by weight of PVDF and 1 part by weight of F-NDs to obtain a slurry. Coat the slurry evenly on a polyimide-based film. Bond the side of the polyimide-based film coated with the slurry to lithium metal. Hot press at 80°C and 0.5MPa. After cooling, peel off the polyimide-based film to obtain a lithium metal anode.

[0071] The remaining raw materials and preparation process are the same as in Example 1.

[0072] Comparative Example 3

[0073] The difference between this comparative example and Example 1 is that ZnO modification is not performed. The specific implementation steps are as follows:

[0074] S1, Cu 70 Al 30 The precursor was placed in a 0.5M HCl solution and etched at 4V for 30 minutes to obtain a porous copper-aluminum framework; molten lithium was poured into the porous copper-aluminum framework to obtain lithium metal.

[0075] S2. Lithium metal is immersed in a deionized aqueous solution containing 2 wt% FDA and 1 wt% SDS, and then 0.5 wt% TPC DCM solution is slowly added. The reaction is carried out at the interface between the deionized aqueous solution and the DCM solution for 3 min. The lithium metal is then immersed in a LiPF6 / EC solution containing 5 wt% GaP nanoparticles (LiPF6 and EC volume ratio is 1:1) and heat-treated at 60℃ for 40 min to initiate an interfacial reaction to generate a Li3PO4 / LixGa composite, thus obtaining lithium metal modified with a functional composite layer.

[0076] S3. Mix 9 parts by weight of PVDF and 1 part by weight of F-NDs to obtain a slurry. Coat the slurry evenly on a polyimide-based film. Bond the side of the polyimide-based film coated with the slurry to the lithium metal modified with the functional composite layer. Hot press at 80°C and 0.5MPa. After cooling, peel off the polyimide-based film to obtain a lithium metal anode.

[0077] The remaining raw materials and preparation process are the same as in Example 1.

[0078] Comparative Example 4

[0079] The difference between this comparative example and Example 1 is that neither furanyl polyamide coating nor F-NDs modification is performed. The specific implementation steps are as follows:

[0080] S1, Cu 70 Al 30 The precursor was placed in a 0.5M HCl solution and etched at 4V for 30 min to obtain a porous copper-aluminum framework; the porous copper-aluminum framework was placed in a 0.05M Zn(NO3)2 and 0.05M MTA reaction solution and reacted at 90℃ for 3 h to obtain a ZnO-modified conductive framework; molten lithium was poured into the ZnO-modified conductive framework to obtain lithium metal;

[0081] S2. Immerse lithium metal in a LiPF6 / EC solution containing 5wt% GaP nanoparticles (LiPF6 and EC volume ratio is 1:1) and heat treat at 60℃ for 40 min to obtain a lithium metal anode.

[0082] The remaining raw materials and preparation process are the same as in Example 1.

[0083] Performance testing

[0084] The performance of the lithium metal anodes with furanyl polyamide protective layers prepared in Examples 1-6 and Comparative Examples 1-4 was tested. The specific test items are as follows:

[0085] Coulombic efficiency: According to GB / T44027.1-2024 "Determination of Carbon Materials - Part 1: Determination of Initial Discharge Specific Capacity, Initial Coulombic Efficiency, and Capacity Retention Rate at Different Discharge Rates", the efficiency was determined by charge-discharge at a rate of 0.1C (voltage range 0.01-1.5V vs. Li). + / Li), calculate the coulomb efficiency;

[0086] Rate performance: According to GB / T44027.1-2024 "Determination of carbon materials - Part 1: Determination of initial discharge specific capacity, initial coulombic efficiency and capacity retention rate at different discharge rates", the current density was increased in steps from 0.2C to 5C, and the capacity retention rate at each rate was tested.

[0087] Cyclic stability: According to GB / T44027.1-2024 "Determination of carbon materials - Part 1: Determination of initial discharge specific capacity, initial coulombic efficiency and capacity retention rate at different discharge rates", the capacity retention rate was recorded after 500 cycles at 1C.

[0088] Critical current density (mA / cm2): The symmetrical cell linear scanning voltammetry method was used, with the current increasing in increments of 0.1 mA / cm2 until the voltage suddenly dropped, and the critical current density was recorded.

[0089] The results are shown in Table 1:

[0090] Table 1

[0091]

[0092] As shown in Table 1, the lithium metal anodes provided in each embodiment all exhibit excellent coulombic efficiency, rate performance, cycle stability, and critical current density. This is due to the ZnO-modified three-dimensional framework, the furanyl polyamide protective layer / Li3PO4 / Li x The synergistic effect of Ga composite interface layer and F-NDs alleviates the volume change during lithium deposition / stripping process, physically suppresses lithium dendrites, and effectively inhibits the occurrence of side reactions. Compared with Example 1, Examples 2-6 have reasonable adjustments to the components, and the results show that the performance is better.

[0093] Compared to Example 1, Comparative Example 1, without F-NDs modification, resulted in decreased mechanical strength and electrolyte corrosion resistance of the prepared lithium metal anode system, as well as reduced ability to inhibit dendrite growth, leading to a decline in the electrochemical performance of the lithium metal anode. Since the in-situ formation of a furanyl polyamide protective layer through interfacial polymerization can impart excellent mechanical strength and thermal stability to the coating, and can also interact with Li3PO4 / Li x The Ga composite interface layer synergistically enhances ion transport performance and the stability of the SEI film at the interface. Therefore, the performance of Comparative Example 2 is significantly lower than that of Example 1. In Comparative Example 3, the absence of ZnO modification leads to a decrease in the bonding force between the furan-based polyamide protective layer and lithium metal, resulting in a decrease in rate performance and cycle stability. In Comparative Example 4, not only do the inherent properties of the furan-based polyamide coating and F-NDs disappear, but the close adhesion between the furan-based polyamide protective layer and F-NDs also optimizes the electrode / electrolyte interface contact, reduces interface impedance, and homogenizes the lithium ion flow. Therefore, the experimental results show a significant decrease in electrochemical performance.

[0094] The above-disclosed embodiments are merely a few specific examples of the present invention. However, the embodiments of the present invention are not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A method for preparing a lithium metal anode with a furanyl polyamide protective layer, characterized in that, Includes the following steps: S1, Cu 70 Al 30 The precursor was etched in HCl solution to obtain a porous copper-aluminum framework; the porous copper-aluminum framework was placed in Zn(NO3)2 and HMTA reaction solution and heated to react to obtain a ZnO-modified conductive framework. Lithium metal is obtained by injecting molten lithium into a ZnO-modified conductive framework. S2. Lithium metal is immersed in a deionized aqueous solution of FDA and SDS, and then a DCM solution of TPC is slowly added for interfacial reaction; after immersion in a LiPF6 / EC solution containing GaP nanoparticles and heat treatment, lithium metal modified with a functional composite layer is obtained. S3. Mix PVDF and F-NDs to obtain a slurry. Apply the slurry to lithium metal modified with a functional composite layer by hot pressing to obtain a lithium metal anode with a furan-based polyamide protective layer. The weight ratio of FDA, SDS, and deionized water is (1.5-2.5):(0.5-1.5):(100-120); the weight ratio of TPC and DCM is (0.3-0.7):(100-110); HMTA refers to hexamethylenetetramine, FDA refers to furanyl diamine, SDS refers to sodium dodecyl sulfate, TPC refers to terephthaloyl chloride, and DCM refers to dichloromethane.

2. The method for preparing a lithium metal anode with a furanyl polyamide protective layer according to claim 1, characterized in that, The concentration of the HCl solution is 0.5-0.8M; the etching is performed at 3-4V for 30-60 minutes; the heating reaction is performed at 80-90℃ for 3-4 hours.

3. The method for preparing a lithium metal anode with a furanyl polyamide protective layer according to claim 1, characterized in that, The concentration of Zn(NO3)2 in the reaction solution of Zn(NO3)2 and HMTA is 0.03-0.06M, and the concentration of HMTA is 0.03-0.06M.

4. The method for preparing a lithium metal anode with a furanyl polyamide protective layer according to claim 1, characterized in that, The interface reaction is carried out at the interface between the deionized aqueous solution and the DCM solution for 2-4 minutes; the heat treatment is carried out at 50-60℃ for 30-60 minutes.

5. The method for preparing a lithium metal anode with a furanyl polyamide protective layer according to claim 1, characterized in that, The weight ratio of GaP nanoparticles to LiPF6 / EC solution is (3-8):100; the volume ratio of LiPF6 to EC in LiPF6 / EC solution is (0.8-1):(0.8-1).

6. The method for preparing a lithium metal anode with a furanyl polyamide protective layer according to claim 1, characterized in that, The mass ratio of PVDF to F-NDs is (8-9):(1-2).

7. The method for preparing a lithium metal anode with a furanyl polyamide protective layer according to claim 1, characterized in that, The hot-press coating involves uniformly coating a slurry onto a polyimide-based film, then hot-pressing the slurry-coated side of the polyimide-based film onto a lithium metal substrate modified with a functional composite layer, and finally peeling off the polyimide-based film after cooling. The hot pressing is performed at 70-80℃ and 0.5-0.6MPa.

8. A lithium metal anode with a furanyl polyamide protective layer, characterized in that, It is prepared by any one of the methods for preparing lithium metal anodes according to claims 1-7.

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