Preparation process of furyl-containing aramid fiber coated lithium battery diaphragm

Abstract

The invention discloses a preparation process of a furyl-containing aramid fiber coated lithium battery diaphragm, and belongs to the technical field of battery diaphragms.The preparation process comprises the following steps that under the nitrogen protection condition, calcium chloride is added into an aprotic polar solvent, stirring and dissolving are performed, then aromatic diamine monomers are added, stirring and dissolving are performed at the temperature of 10 + / -0.5 DEG C, and a reaction is performed at the temperature of 10 + / -0.5 DEG C; adding furandicarbonyl chloride to obtain a furyl-containing aramid polymer solution; diluting the furyl aramid polymer solution, adding maleimide to activate the UiO-66-NH2 carbon material, and continuously stirring and dispersing to obtain an aramid coating solution; and coating the surface of the base membrane with the aramid fiber coating liquid, and carrying out coagulating bath curing, water washing and vacuum drying to obtain the furyl-containing aramid fiber coated lithium battery diaphragm. A porous coating film is formed through the synergistic effect of furyl-containing aramid fiber and a maleimide activated UiO-66-NH2 carbon material, dendritic crystal growth is jointly inhibited through uniform lithium ion flux distribution, and the cycle performance of the diaphragm is improved.

Description

Technical Field

[0001] This invention belongs to the field of battery separator technology, specifically relating to a preparation process of a lithium battery separator coated with furanyl aramid. Background Technology

[0002] As a critical component within lithium-ion batteries, the performance of the separator directly impacts battery safety and efficiency. Traditional polyolefin separators, such as polyethylene (PE) and polypropylene (PP), are widely used due to their low cost and good chemical stability, but they have significant drawbacks. First, their thermal stability is insufficient; at high temperatures, the separator is prone to shrinkage or even melting (e.g., PE's melting point is approximately 135°C, and PP's is approximately 165°C), leading to internal short circuits and potential safety hazards such as fires or explosions. Second, the non-polar properties of polyolefin materials result in poor compatibility with polar electrolytes, leading to poor electrolyte wettability, increased internal resistance, hindered efficient ion transport, and reduced charge / discharge rates and overall battery performance. Furthermore, the limited mechanical strength of polyolefin separators makes it difficult to effectively block lithium dendrites formed during charging and discharging. Once dendrites pierce the separator, they can also cause internal short circuits, seriously threatening battery safety and cycle life.

[0003] To overcome these inherent defects of polyolefin separators, studies have explored improving separator performance through coating with nanofiber / particle blends. This composite structure not only retains the original advantages of the polyolefin substrate but also significantly enhances the overall performance of the separator. For example, the high glass transition temperature and melting point of aramid fibers, combined with the thermal inertia of inorganic particles, greatly enhance the thermal dimensional stability of the separator, effectively suppressing high-temperature shrinkage and deformation, and improving the high-temperature safety of the battery. The large specific surface area and high surface energy of nanoparticles increase the surface roughness and polarity of the separator, significantly improving its wettability and adsorption capacity for electrolytes, thereby reducing internal resistance and increasing ionic conductivity. However, the bonding force between the coating layer and the polyolefin substrate is often weak. Under the stress of long-term battery cycling or high-temperature environments, coating peeling or nanoparticle aggregation can easily occur, affecting the long-term stability of separator performance. Summary of the Invention

[0004] The purpose of this invention is to provide a preparation process for a lithium battery separator coated with furanyl aramid to solve the problem of poor cycle life of polyolefin separators.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A process for preparing a furanyl aramid-coated lithium battery separator includes the following steps:

[0007] Under nitrogen protection, calcium chloride was added to an aprotic polar solvent and stirred until dissolved. Then, an aromatic diamine monomer was added and stirred until dissolved. Finally, furanyl chloride was added at 10±0.5℃ to obtain a furanyl aramid polymer solution.

[0008] After diluting the furanyl aramid polymer solution, maleimide was added to activate the UiO-66-NH2@carbon material, and the mixture was stirred and dispersed to obtain an aramid coating solution. The aramid coating solution was coated on the surface of the base film, and after curing in a coagulation bath, washing with water, and vacuum drying at 60-80℃, a furanyl aramid coated lithium battery separator was obtained.

[0009] This invention uses aromatic diamine monomers and furanyl dicarboxylate chloride as monomers for furanyl-containing aramids, and calcium chloride as an auxiliary agent, to prepare a furanyl-containing aramid polymer solution through reaction in an aprotic polar solvent. Then, maleimide is introduced to activate UiO-66-NH2@carbon material to prepare an aramid coating solution, which is subsequently coated onto a base film and solidified in a coagulation bath. Water and the aprotic polar solvent have good affinity, and the aprotic polar solvent rapidly diffuses from the coating solution into the coagulation bath, initiating phase separation of the polymer in the coating solution to form a porous coating film.

[0010] The oxygen atoms in the furan ring of furanyl aramid possess lone pairs of electrons, which can form hydrogen bonds or dipole-dipole interactions with polar solvents (such as carbonates) in the electrolyte, improving the wettability of the membrane to the electrolyte and thus enhancing lithium-ion migration efficiency. Furanyl aramid can also form cross-linked networks with maleimide-activated UiO-66-NH2@carbon materials through Diels-Alder reactions and other processes, further strengthening mechanical properties.

[0011] In some specific implementations, the aromatic diamine monomer is at least one of p-phenylenediamine, m-phenylenediamine, m-phenylenediamine, and 4,4′-diaminodiphenyl ether;

[0012] The aprotic polar solvent is at least one of N-methylpyrrolidone and 1,5-dimethyl-2-pyrrolidone.

[0013] In some specific implementations, the ratio of aprotic polar solvent, calcium chloride, aromatic diamine monomer, and furanyl chloride is 85 mL: 5.4-5.5 g: 0.025 mol: 0.025-0.03 mol.

[0014] In some specific implementations, the solid content of the diluted furanyl aramid polymerization solution is 5%–6%; the mass fraction of maleimide-activated UiO-66-NH2@carbon material in the aramid coating solution is 2%–6%. The maleimide-activated UiO-66-NH2@carbon material, acting as a filler, has a nucleation effect, promoting heterogeneous nucleation, reducing the energy required for pore formation and nucleation, and increasing the number and uniformity of pores. Higher contents of maleimide-activated UiO-66-NH2@carbon material result in more nucleation sites and a more uniform pore distribution; however, excessively high contents may lead to agglomeration, resulting in uneven pore distribution.

[0015] In some specific implementations, the base membrane is either a polypropylene diaphragm or a polyethylene diaphragm.

[0016] In some specific implementations, maleimide-activated UiO-66-NH2@carbon material is obtained by amidation reaction of maleic anhydride with amino groups on the surface of UiO-66-NH2@carbon material under the combined action of sodium acetate, acetic anhydride and triethylamine.

[0017] In some specific implementations, maleimide-activated UiO-66-NH2@carbon materials are prepared through the following steps:

[0018] Under a nitrogen atmosphere, UiO-66-NH2@ carbon material was added to acetone and ultrasonically dispersed. Maleic anhydride was then added and stirred for 2-3 hours. Sodium acetate, acetic anhydride, and triethylamine were then added. The temperature was set at 50-60℃, and the reaction was continued for 16-24 hours. After the reaction was completed, the material was washed with saturated sodium chloride aqueous solution, centrifuged, and vacuum dried at 60℃ to obtain maleimide-activated UiO-66-NH2@ carbon material.

[0019] In some specific implementations, the molar ratio of maleic anhydride, sodium acetate, acetic anhydride and triethylamine is 0.06-0.07 mol: 0.55-0.65 g: 0.06-0.07 mol: 3.5-4.0 mL; the mass ratio of UiO-66-NH2@ carbon material to maleic anhydride is 10 g: 4-6 g.

[0020] In some specific implementations, UiO-66-NH2@carbon materials are prepared through the following steps:

[0021] Zirconium chloride and 2-aminoterephthalic acid were added to N,N-dimethylformamide and stirred until dissolved. Then, carbon material modified with oxygen-containing functional groups was added, and the reaction was carried out at 70-80℃ for 10-12 hours. After the reaction, the mixture was centrifuged, washed, and dried to obtain UiO-66-NH2@carbon material. UiO-66-NH2 is a functionalized metal-organic framework material whose core structure consists of zirconium (Zr) metal clusters and organic ligands, modified by introducing amino (-NH2) functional groups to facilitate the subsequent introduction of maleimide functional groups. UiO-66-NH2 possesses abundant and ordered nanoscale pores and a high specific surface area, enabling the membrane to form more channels, increasing the contact area with the electrolyte, which is beneficial for lithium-ion transport, thereby improving the wettability and ionic conductivity of the membrane. Its stable three-dimensional structure can improve the mechanical strength of the membrane, making it less prone to deformation during battery charging and discharging, maintaining structural stability, and extending battery life. The pore size and structure of UiO-66-NH2 exhibit selective permeability, allowing lithium ions to pass preferentially while hindering the transport of some large-volume anions and impurity ions, reducing their interference with lithium ion transport. It can also suppress the occurrence of side reactions, thereby improving the charge-discharge efficiency and cycle stability of the battery.

[0022] Uniform lithium-ion flux distribution can induce lithium-ions to deposit more evenly on the electrode surface, resulting in a compact, two-dimensional lithium deposition. This avoids the formation of dendrites due to excessively high local lithium-ion concentrations, reduces the risk of lithium dendrites piercing the separator and causing short circuits, and improves battery safety.

[0023] In some specific implementations, the molar ratio of zirconium chloride to 2-aminoterephthalic acid is 1:1.3-1.4.

[0024] In some specific implementations, the oxygen-containing functional group-modified carbon material is either graphene oxide or carboxylated carbon nanotubes.

[0025] The beneficial effects of this invention are:

[0026] This invention prepares a furanyl aramid coating solution by polymerizing aromatic diamines with furanyl dicarboxylate chloride, and combines it with maleimide-activated UiO-66-NH2@carbon material filler, forming a porous coating film through phase separation. This invention utilizes the synergistic effect of furanyl aramid and maleimide-activated UiO-66-NH2@carbon material to form a coating film in a proton-polar solvent. The nanopores of the metal-organic framework and the complementary dimensional channels of the carbon material synergistically enhance ion transport efficiency; the lone pair electrons of the furan ring enhance electrolyte wettability, and the cross-linked network constructed through the Diels-Alder reaction strengthens mechanical strength; the ion sieving function of UiO-66-NH2 and the uniform lithium-ion flux distribution jointly inhibit dendrite growth; the maleimide-activated UiO-66-NH2@carbon material, as a filler, promotes heterogeneous nucleation, increases the uniformity and number of pores, and improves lithium-ion transport efficiency; its stable three-dimensional framework enhances membrane strength and inhibits dendrite growth, improving battery cycle performance. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0028] The following is a detailed description of the preparation process of a furanyl aramid-coated lithium battery separator according to an embodiment of this application.

[0029] The following is a detailed description with reference to specific examples.

[0030] Preparation Example 1

[0031] Preparation of maleimide-activated UiO-66-NH2@carbon materials:

[0032] Zirconium chloride and 2-aminoterephthalic acid were added to N,N-dimethylformamide and stirred until dissolved. Carboxylated carbon nanotubes were then added, and the reaction was carried out at 80℃ for 10 hours. After the reaction was completed, the mixture was centrifuged, washed with water, and dried to obtain UiO-66-NH2@carbon material. The ratio of N,N-dimethylformamide, zirconium chloride, 2-aminoterephthalic acid, and carboxylated carbon nanotubes was 100 mL: 1.65 g: 1.78 g: 5 g.

[0033] Under a nitrogen atmosphere, UiO-66-NH2@ carbon material was added to acetone and ultrasonically dispersed. Maleic anhydride was then added and stirred for 2 hours. Sodium acetate, acetic anhydride, and triethylamine were then added. The temperature was set at 50°C, and the reaction was continued for 20 hours. After the reaction was completed, the material was washed with saturated sodium chloride aqueous solution, centrifuged, and vacuum dried at 60°C to obtain maleimide-activated UiO-66-NH2@ carbon material.

[0034] The molar ratio of maleic anhydride, sodium acetate, acetic anhydride and triethylamine is 0.06 mol: 0.55 g: 0.06 mol: 3.5 mL; the mass ratio of UiO-66-NH2@ carbon material and maleic anhydride is 10 g: 5 g.

[0035] Preparation Example 2

[0036] Preparation of maleimide-activated UiO-66-NH2@carbon materials:

[0037] Zirconium chloride and 2-aminoterephthalic acid were added to N,N-dimethylformamide and stirred until dissolved. Graphene oxide was then added, and the reaction was carried out at 80℃ for 10 hours. After the reaction was completed, the mixture was centrifuged, washed with water, and dried to obtain UiO-66-NH2@carbon material. The ratio of N,N-dimethylformamide, zirconium chloride, 2-aminoterephthalic acid, and graphene oxide was 100 mL: 1.65 g: 1.78 g: 5 g.

[0038] Under a nitrogen atmosphere, UiO-66-NH2@ carbon material was added to acetone and ultrasonically dispersed. Maleic anhydride was then added and stirred for 2 hours. Sodium acetate, acetic anhydride, and triethylamine were then added, and the reaction was continued at 50°C for 20 hours. After the reaction was complete, the mixture was washed with a saturated sodium chloride aqueous solution, centrifuged, and vacuum dried at 60°C to obtain maleimide-activated UiO-66-NH2@ carbon material. The molar ratio of maleic anhydride, sodium acetate, acetic anhydride, and triethylamine was 0.06 mol: 0.55 g: 0.06 mol: 3.5 mL; the mass ratio of UiO-66-NH2@ carbon material to maleic anhydride was 10 g: 5 g.

[0039] Example 1

[0040] This embodiment provides a process for preparing a furanyl aramid-coated lithium battery separator, including the following steps:

[0041] Under nitrogen protection, calcium chloride was added to N-methylpyrrolidone and stirred until dissolved. Then, an aromatic diamine monomer was added and stirred until dissolved. Finally, furanyl dicarboxylate chloride was added at 10±0.5℃ to obtain a furanyl-containing aramid polymer solution. The ratio of N-methylpyrrolidone, calcium chloride, aromatic diamine monomer, and furanyl dicarboxylate chloride was 85 mL: 5.4 g: 0.025 mol: 0.025 mol. The aromatic diamine monomer was p-phenylenediamine.

[0042] After diluting the furanyl aramid polymerization solution, the maleimide-activated UiO-66-NH2@carbon material prepared in Preparation Example 1 was added, and the mixture was stirred and dispersed to obtain an aramid coating solution. The aramid coating solution was coated onto the surface of a polypropylene separator, cured in a coagulation bath (solution was water), washed with water, and vacuum dried at 80°C to obtain a furanyl aramid-coated lithium battery separator with a coating thickness of 4 μm. The solid content of the diluted furanyl aramid polymerization solution was 6%; the mass fraction of the maleimide-activated UiO-66-NH2@carbon material in the aramid coating solution was 6%.

[0043] Example 2

[0044] This embodiment provides a process for preparing a furanyl aramid-coated lithium battery separator, including the following steps:

[0045] The furanyl aramid polymerization solution (same as in Example 1) was diluted, and the maleimide-activated UiO-66-NH2@carbon material prepared in Preparation Example 1 was added. The mixture was stirred and dispersed to obtain an aramid coating solution. This aramid coating solution was coated onto the surface of a polypropylene separator, cured in a coagulation bath (water solution), washed with water, and vacuum dried at 80°C to obtain a furanyl aramid-coated lithium battery separator with a coating thickness of 4 μm. The solid content of the diluted furanyl aramid polymerization solution was 6%; the mass fraction of the maleimide-activated UiO-66-NH2@carbon material in the aramid coating solution was 2%.

[0046] Example 3

[0047] This embodiment provides a process for preparing a furanyl aramid-coated lithium battery separator, including the following steps:

[0048] The furanyl aramid polymerization solution (same as in Example 1) was diluted, and the maleimide-activated UiO-66-NH2@carbon material prepared in Preparation Example 1 was added. The mixture was stirred and dispersed to obtain an aramid coating solution. This aramid coating solution was coated onto the surface of a polypropylene separator, cured in a coagulation bath (water solution), washed with water, and vacuum dried at 80°C to obtain a furanyl aramid-coated lithium battery separator with a coating thickness of 4 μm. The solid content of the diluted furanyl aramid polymerization solution was 6%; the mass fraction of the maleimide-activated UiO-66-NH2@carbon material in the aramid coating solution was 3%.

[0049] Example 4

[0050] This embodiment provides a process for preparing a furanyl aramid-coated lithium battery separator, including the following steps:

[0051] The furanyl aramid polymerization solution (same as in Example 1) was diluted, and the maleimide-activated UiO-66-NH2@carbon material prepared in Preparation Example 1 was added. The mixture was stirred and dispersed to obtain an aramid coating solution. This aramid coating solution was coated onto the surface of a polypropylene separator, cured in a coagulation bath (water solution), washed with water, and vacuum dried at 80°C to obtain a furanyl aramid-coated lithium battery separator with a coating thickness of 4 μm. The solid content of the diluted furanyl aramid polymerization solution was 5%; the mass fraction of the maleimide-activated UiO-66-NH2@carbon material in the aramid coating solution was 6%.

[0052] Example 5

[0053] This embodiment provides a process for preparing a furanyl aramid-coated lithium battery separator, including the following steps:

[0054] Under nitrogen protection, calcium chloride was added to N-methylpyrrolidone and stirred until dissolved. Then, an aromatic diamine monomer was added and stirred until dissolved. Finally, furanyl dicarboxylate chloride was added at 10±0.5℃ to obtain a furanyl aramid polymer solution. The ratio of N-methylpyrrolidone, calcium chloride, aromatic diamine monomer, and furanyl dicarboxylate chloride was 85 mL: 5.4 g: 0.025 mol: 0.025 mol. The aromatic diamine monomer was α-diaminodiphenyl ether.

[0055] After diluting the furanyl aramid polymerization solution, the maleimide-activated UiO-66-NH2@carbon material prepared in Preparation Example 1 was added, and the mixture was stirred and dispersed to obtain an aramid coating solution. The aramid coating solution was coated onto the surface of a polypropylene separator, cured in a coagulation bath (solution was water), washed with water, and vacuum dried at 80°C to obtain a furanyl aramid-coated lithium battery separator with a coating thickness of 4 μm. The solid content of the diluted furanyl aramid polymerization solution was 6%; the mass fraction of the maleimide-activated UiO-66-NH2@carbon material in the aramid coating solution was 6%.

[0056] Example 6

[0057] This embodiment provides a process for preparing a furanyl aramid-coated lithium battery separator, including the following steps:

[0058] Under nitrogen protection, calcium chloride was added to N-methylpyrrolidone and stirred until dissolved. Then, an aromatic diamine monomer was added and stirred until dissolved. Finally, furanyl dicarboxylate chloride was added at 10±0.5℃ to obtain a furanyl-containing aramid polymer solution. The ratio of N-methylpyrrolidone, calcium chloride, aromatic diamine monomer, and furanyl dicarboxylate chloride was 85 mL: 5.4 g: 0.025 mol: 0.025 mol. The aromatic diamine monomer was p-phenylenediamine.

[0059] After diluting the furanyl aramid polymerization solution, the maleimide-activated UiO-66-NH2@carbon material prepared in Preparation Example 2 was added, and the mixture was stirred and dispersed to obtain an aramid coating solution. The aramid coating solution was coated onto the surface of a polypropylene separator, cured in a coagulation bath (solution was water), washed with water, and vacuum dried at 80°C to obtain a furanyl aramid-coated lithium battery separator with a coating thickness of 4 μm. The solid content of the diluted furanyl aramid polymerization solution was 6%; the mass fraction of the maleimide-activated UiO-66-NH2@carbon material in the aramid coating solution was 6%.

[0060] Comparative Example 1

[0061] The difference between this comparative example and Example 1 is that furanyl chloride is replaced with an equimolar amount of terephthaloyl chloride, while the other raw materials and preparation process remain the same as in Example 1.

[0062] Comparative Example 2

[0063] Compared with Example 1, the mass fraction of maleimide-activated UiO-66-NH2@carbon material in the aramid coating solution in this comparative example is 12%, while the remaining raw materials and preparation process are the same as in Example 1.

[0064] Comparative Example 3

[0065] The difference between this comparative example and Example 1 is that the maleimide-activated UiO-66-NH2@carbon material is replaced with carboxylated carbon nanotubes, while the other raw materials and preparation process remain the same as in Example 1.

[0066] Comparative Example 4

[0067] The difference between this comparative example and Example 1 is that the maleimide-activated UiO-66-NH2@carbon material is replaced with the UiO-66-NH2@carbon material in Preparation Example 1.

[0068] The lithium battery separators prepared for performance testing in Examples 1-6 and Comparative Examples 1-4 were tested for lithium-ion transference number, puncture resistance, and electrical properties.

[0069] Puncture resistance test: According to the relevant records in GB / T 23318-2019 "Determination of puncture strength of textiles", the diaphragm puncture strength obtained in the test examples and comparative examples was tested.

[0070] Electrical performance testing: The CR2032 button cell was assembled in the order of positive electrode active material, electrolyte, separator, and lithium sheet. The battery was then pressed tightly using a battery packaging machine and left to stand for more than 12 hours until it stabilized. After that, it was charged and discharged at 0.5C rate at 25℃ for 500 cycles to test the capacity retention rate before and after the cycles.

[0071] The results are shown in Table 1:

[0072] Table 1

[0073] project Lithium-ion transference number Puncture strength / g Capacity retention rate / % Example 1 0.78 413 85.1 Example 2 0.73 395 84.4 Example 3 0.76 387 84.3 Example 4 0.74 406 84.6 Example 5 0.77 410 85.0 Example 6 0.72 417 84.2 Comparative Example 1 0.68 364 82.0 Comparative Example 2 0.66 357 81.2 Comparative Example 3 0.54 331 79.5 Comparative Example 4 0.63 343 80.8

[0074] According to Table 1, combined with Examples 1 and 6, graphene oxide and carboxylated carbon nanotubes provide two-dimensional and one-dimensional ion channels, respectively. The tubular structure of carbon nanotubes can reduce ion diffusion resistance and is superior to the layered structure of graphene oxide in improving lithium ion transference number.

[0075] As can be seen from Example 1 and Comparative Examples 1-4, in samples lacking furan rings or maleimide groups, it is impossible to construct a cross-linked network to enhance mechanical strength through the Diels-Alder reaction, resulting in poorer performance of the samples compared to the examples. The ion sieving function of UiO-66-NH2 and the uniform lithium-ion flux distribution jointly inhibit dendrite growth. At the same time, there is an interaction between UiO-66-NH2@carbon material and furan-containing aramid, which enables UiO-66-NH2@carbon material to be better dispersed in the coating. The uniform lithium-ion flux distribution jointly inhibits dendrite growth, thereby improving the cycle performance of the membrane.

[0076] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0077] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A preparation process for a lithium battery separator coated with furanyl aramid, characterized in that, Includes the following steps: Under nitrogen protection, calcium chloride was added to an aprotic polar solvent and stirred until dissolved. Then, an aromatic diamine monomer was added and stirred until dissolved. Finally, furanyl chloride was added at 10±0.5℃ to obtain a furanyl aramid polymer solution. After diluting the furanyl aramid polymer solution, maleimide was added to activate the UiO-66-NH2@carbon material, and the mixture was stirred and dispersed to obtain an aramid coating solution. The aramid coating solution was coated on the surface of the base film, and after curing in a coagulation bath, washing with water, and vacuum drying, a lithium battery separator containing furanyl aramid was obtained.

2. The preparation process of a furanyl aramid-coated lithium battery separator according to claim 1, characterized in that, The aromatic diamine monomer is at least one selected from p-phenylenediamine, m-phenylenediamine, m-phenylenediamine, and 4,4′-diaminodiphenyl ether; The aprotic polar solvent is at least one of N-methylpyrrolidone and 1,5-dimethyl-2-pyrrolidone.

3. The preparation process of a furanyl aramid-coated lithium battery separator according to claim 1, characterized in that, The ratio of aprotic polar solvent, calcium chloride, aromatic diamine monomer, and furanyl chloride is 85 mL. 5.4-5.5g: 0.025mol: 0.025-0.03mol.

4. The preparation process of a furanyl aramid-coated lithium battery separator according to claim 1, characterized in that, The solid content of the diluted furanyl aramid polymerization solution is 5%–6%; the mass fraction of maleimide-activated UiO-66-NH2@carbon material in the aramid coating solution is 2%–6%.

5. The preparation process of a furanyl aramid-coated lithium battery separator according to claim 1, characterized in that, The base membrane is either a polypropylene diaphragm or a polyethylene diaphragm.

6. The preparation process of a furanyl aramid-coated lithium battery separator according to claim 1, characterized in that, Maleimide-activated UiO-66-NH2@carbon material is obtained by amidation reaction of maleic anhydride with amino groups on the surface of UiO-66-NH2@carbon material under the combined action of sodium acetate, acetic anhydride and triethylamine.

7. The preparation process of a furanyl aramid-coated lithium battery separator according to claim 1, characterized in that, Maleimide-activated UiO-66-NH2@carbon materials are prepared through the following steps: Under a nitrogen atmosphere, UiO-66-NH2@ carbon material was added to acetone and ultrasonically dispersed. Maleic anhydride was then added and stirred for 2-3 hours. Sodium acetate, acetic anhydride, and triethylamine were then added. The temperature was set at 50-60℃, and the reaction was continued for 16-24 hours. After the reaction was completed, the material was washed with saturated sodium chloride aqueous solution, centrifuged, and vacuum dried at 60℃ to obtain maleimide-activated UiO-66-NH2@ carbon material.

8. The preparation process of a furanyl aramid-coated lithium battery separator according to claim 7, characterized in that, The molar ratio of maleic anhydride, sodium acetate, acetic anhydride and triethylamine is 0.06-0.07 mol: 0.55-0.65 g: 0.06-0.07 mol: 3.5-4.0 mL; the mass ratio of UiO-66-NH2@ carbon material to maleic anhydride is 10 g: 4-6 g.

9. The preparation process of a furanyl aramid-coated lithium battery separator according to claim 7, characterized in that, UiO-66-NH2@carbon material is prepared through the following steps: Zirconium chloride and 2-aminoterephthalic acid were added to N,N-dimethylformamide and stirred until dissolved. Then, carbon material modified with oxygen-containing functional groups was added. The temperature was set at 70-80℃ and the reaction was carried out for 10-12 hours. After the reaction was completed, the carbon material was obtained by centrifugation, washing with water and drying. The molar ratio of zirconium chloride to 2-aminoterephthalic acid was 1:1.3-1.

4.

10. The preparation process of a furanyl aramid-coated lithium battery separator according to claim 1, characterized in that, The carbon materials modified with oxygen-containing functional groups are one of graphene oxide and carboxylated carbon nanotubes.