Preparation method of wide-temperature-range high-safety through network structure functional fiber-based solid electrolyte

Abstract

This invention provides a method for preparing a wide-temperature-range, high-safety, through-network structure functional fiber-based solid electrolyte, comprising: Step 1, co-dissolving polyacrylonitrile and an aldehyde-containing monomer in solvent A to prepare an aldehyde-containing functional spinning solution; Step 2, preparing an aldehyde-based fiber precursor from the spinning solution; Step 3, using the aldehyde-based fiber precursor as a template, inducing fiber surface polymerization in a system containing an ammonia-containing monomer, a proton source, and solvent B to prepare a core-shell structure COF fiber membrane; Step 4, loading an ionic liquid onto the surface of the core-shell structure COF fiber membrane to prepare an ionic liquid-functionalized COF fiber membrane; Step 5, coating the upper and lower surfaces of the ionic liquid-functionalized COF fiber membrane obtained in Step 4 with polyethylene oxide to prepare a through-network structure functional fiber-based solid electrolyte. The solid electrolyte of this invention possesses excellent mechanical strength, wide-temperature-range high stability, and fast ion transport capability, making it suitable for high-safety battery systems under extreme high and low temperature environments.

Description

Technical Field

[0001] This invention relates to the fields of new energy materials for extreme conditions, solid electrolytes, and wide-temperature-range solid alkali metal batteries, specifically to a method for preparing a wide-temperature-range, high-safety, through-network structure functional fiber-based solid electrolyte. Background Technology

[0002] Solid-state lithium batteries, as the next generation of high-safety, high-energy-density energy storage systems, have become a key direction for solving the safety hazards of traditional liquid lithium batteries and meeting the high-performance energy storage needs of power batteries, energy storage power stations, aerospace, and other fields, thanks to their core advantages such as no leakage risk, suppression of lithium dendrite growth, and compatibility with high-voltage cathode materials. Solid-state electrolytes, as the core component of solid-state lithium batteries, directly determine key performance characteristics such as ion transport efficiency, cycle stability, and operating temperature window. Their research and industrialization are the core drivers for promoting the practical application of solid-state lithium batteries, and have become a research hotspot in materials science and electrochemistry in recent years. The industry's demand for solid-state electrolyte materials that combine high ionic conductivity, excellent mechanical stability, and wide temperature range adaptability is increasingly urgent.

[0003] Polyethylene oxide (PEO)-based polymer solid electrolytes have become one of the most widely studied and industrially promising solid electrolyte systems due to their excellent film-forming properties, superior compatibility with lithium metal anodes, mild preparation processes, and low raw material costs. Ion transport in PEO electrolytes primarily relies on polymer chain segment movement to achieve lithium salt dissociation and lithium ion migration. However, this system has inherent structural defects; its molecular chains easily form highly crystalline regions, significantly reducing ionic conductivity at room temperature. Simultaneously, at high temperatures, intensified polymer chain segment movement leads to a sharp decline in electrolyte mechanical strength, failing to effectively suppress lithium dendrite penetration. At low temperatures, chain segment movement is restricted, further reducing ion transport efficiency. This results in a narrow effective operating temperature window for traditional PEO solid electrolytes, making them unsuitable for extreme high and low temperatures and wide temperature fluctuations in practical applications, becoming a core bottleneck restricting their industrial application.

[0004] Ionic liquids, as a class of molten salts that are liquid at room temperature, possess unique properties such as high ionic conductivity, a wide electrochemical stability window, excellent thermal and chemical stability, non-flammability and low vapor pressure, and are widely used in the modification of polyethylene oxide (PEO) solid electrolytes. Introducing ionic liquids into PEO systems can effectively disrupt the crystalline structure of polymer molecular chains, increase the proportion of amorphous regions, improve ion transport efficiency, and broaden the operating temperature range of the electrolyte, improving its low-temperature ion conductivity and high-temperature thermal stability. However, simple ionic liquid plasticization modification still has significant shortcomings. Excessive ionic liquid can further degrade the mechanical properties of PEO electrolytes, and the limited compatibility between ionic liquids and the polymer matrix easily leads to phase separation and ionic liquid loss, causing the structural stability and electrochemical performance of the electrolyte to rapidly decline with cycling time, making it difficult to meet the long-term cycling performance requirements of solid-state lithium batteries.

[0005] Covalent organic frameworks (COFs), as a class of crystalline porous materials formed by organic monomers linked by covalent bonds, possess highly ordered pore structures, precisely designable molecular skeletons, high specific surface areas, excellent thermal and chemical stability, and abundant modifiable functional groups, providing a new approach to solving the aforementioned bottleneck problems of solid-state electrolytes. COF materials can be introduced into solid-state electrolyte systems as functional frameworks. Their ordered pore structure can construct continuous ion transport channels, and can also immobilize ionic liquids through the pore confinement effect, inhibiting their loss and phase separation. In addition, the rigid framework of COFs can effectively enhance the mechanical properties of polymer electrolytes, inhibit the crystallization of polyethylene oxide, and improve its high-temperature structural stability. While some progress has been made in the research of COF-based composite solid electrolytes, existing systems still suffer from problems such as insufficient interfacial bonding between COF and polymer matrix and ionic liquid, the need to improve the continuity and adaptability of ion transport channels, and the attenuation of ion transport efficiency of multi-component synergy over a wide temperature range. A COF-ionic liquid composite solid electrolyte system that can achieve high ionic conductivity and high structural stability over a wide temperature range has not yet been developed, and the structural design and preparation process of related materials still need further optimization. Summary of the Invention

[0006] Purpose of the invention: The purpose of this invention is to prepare a solid electrolyte integrating a wide-temperature-range, highly stable COF and ionic liquid with a through-network structure, in order to meet the requirements of electrochemical energy storage fields such as power batteries, energy storage power stations, and aerospace for solid lithium batteries to achieve stable operation over a wide temperature range, high ion conduction efficiency, excellent structure, and electrochemical cycle stability.

[0007] To achieve the above objectives, this invention provides a method for preparing a wide-temperature-range, high-safety, through-network structure functional fiber-based solid electrolyte, comprising the following steps:

[0008] Step 1: Prepare an aldehyde-containing functional spinning solution by co-dissolving polyacrylonitrile and aldehyde-containing monomers in solvent A;

[0009] Step 2: Prepare aldehyde-based fiber precursors from the spinning solution obtained in Step 1;

[0010] Step 3: Using the aldehyde-modified fiber precursor obtained in Step 2 as a template, induce fiber surface polymerization in a system containing ammonia monomer, proton source and solvent B to prepare a core-shell structured COF (covalent organic frameworks) fiber membrane.

[0011] Step 4: Load ionic liquid onto the surface of the core-shell COF fiber membrane obtained in Step 3 to prepare an ionic liquid functionalized COF fiber membrane;

[0012] Step 5: Coat the upper and lower surfaces of the ionic liquid-functionalized COF fiber membrane obtained in Step 4 with polyethylene oxide to prepare a solid electrolyte with an integrated COF and ionic liquid through-network structure.

[0013] In step 1, the aldehyde-containing monomer is terephthalaldehyde, isophthalaldehyde, o-phthalaldehyde, trimesonaldehyde, pyromellitic terephthalaldehyde, 2,5-dihydroxyterephthalaldehyde, 2-fluoroterephthalaldehyde, 2-chloroterephthalaldehyde, 4-hydroxyimolecular diphthalaldehyde, 2,4,6-trihydroxytrisonesonaldehyde, 4,4'-biphenyldiphthalaldehyde, 4,4''-triphenyldiphthalaldehyde, or 2,5-dimethoxyterephthalaldehyde. One or more of the following: 2-amino-terephthalaldehyde, 1,4-naphthalenedicarboxyl, 2,6-naphthalenedicarboxyl, 2,6-pyridinedicarboxaldehyde, 2,5-furandicarboxaldehyde, 3,6-carbazoledicarboxaldehyde, 2,3-pyrazinedicarboxaldehyde, 4,4'-bipyridinedicarboxaldehyde, 2,6-quinolinedicarboxaldehyde, 1,3,6,8-pyrenetetracarboxaldehyde, 9,10-anthracenedicarboxaldehyde, glyoxal, succinaldehyde, and glutaraldehyde.

[0014] In step 1, solvent A is N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, N-ethylpyrrolidone, hexamethylphosphoric triamine, sulfolane, dimethyl sulfone, cyclohexanone, methyl isobutyl ketone, dichloromethane, chloroform, 1,2-dichloroethane, tetrahydrofuran, acetone, butanone, or ethyl acetate.

[0015] The mass fraction of polyacrylonitrile in the spinning solution is 5-25%, and the molar ratio of polyacrylonitrile to aldehyde-containing monomer is 50:1-1:1.

[0016] In step 2, the spinning method is one or more of the following: high-voltage electrospinning, ultrasonic-assisted electrospinning, magnetic field-assisted electrospinning, electric field-controlled directional electrospinning, airflow-assisted electrospinning, coaxial electrospinning, emulsion electrospinning, phase separation electrospinning, melt electrospinning, wet spinning, dry spinning, dry-jet wet spinning, gel spinning, high-speed centrifugal spinning, ultrasonic-assisted centrifugal spinning, airflow-assisted centrifugal spinning, electro-jet spinning, electrostatic-centrifugal composite spinning, microfluidic spinning, meltblown spinning, and twin-screw extrusion spinning.

[0017] In step 3, the ammonia-containing monomer is p-phenylenediamine, m-phenylenediamine, o-phenylenediamine, 4,4'-biphenylenediamine, 3,3'-biphenylenediamine, 2,2'-biphenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 2,2'-diaminodiphenyl sulfone, o-toluidine, m-toluidine, or 2,2'-dimethylbenzene. -4,4'-Biphenyldiamine, 1,4-naphthyldiamine, 1,5-naphthyldiamine, 2,6-naphthyldiamine, 2,7-naphthyldiamine, 9,10-anthraphthalenediamine, 4,4'-diaminodiphenyl sulfide, 1,3,5-triaminobenzene, 2,4,6-triaminotoluene, 2,4,6-triaminoresorcinol, 1,3,5-triamino-2,4,6-trimethylbenzene, 1,2,4,5-tetraaminobenzene, 3,3 ',5,5'-Tetraaminobiphenyl, 5,10,15,20-Tetraaminophenylporphyrin, Tetraaminophthalocyanine copper, 2,6-Diaminopyridine, 2,4-Diaminopyridine, 3,5-Diaminopyridine, 2,3-Diaminopyrazine, 2,5-Diaminopyrazine, 2,6-Diaminopyrimidine, 4,5-Diaminoimidazolium, 2,4-Diaminoimidazolium, 2,5-Diaminothiophene, 3,4-Diaminothiophene One or more of the following: 2,5-diaminofuran, 3,6-diaminocarbazole, 2,7-diaminofluorene, 9,9-dimethyl-2,7-diaminofluorene, 2,4-diaminopyrimidine, 5,6-diaminopyrimidine, 1,3,6,8-tetraaminopyrene, 2,3,6,7-tetraaminoanthracene, and 1,4,5,8-tetraaminonaphthalene; wherein the molar ratio of the aldehyde monomer to the ammonia monomer is 10:1 to 1:10.

[0018] In step 3, the proton source is one or more of the following: p-toluenesulfonic acid, benzenesulfonic acid, methanesulfonic acid, trifluoromethanesulfonic acid, dodecylbenzenesulfonic acid, aminosulfonic acid, camphorsulfonic acid, styrenesulfonic acid, naphthalenesulfonic acid, m-methylbenzenesulfonic acid, p-chlorobenzenesulfonic acid, o-nitrobenzenesulfonic acid, formic acid, acetic acid, propionic acid, benzoic acid, o-hydroxybenzoic acid, m-hydroxybenzoic acid, p-hydroxybenzoic acid, trifluoroacetic acid, trichloroacetic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, citric acid, tartaric acid, maleic acid, fumaric acid, pyromellitic acid, terephthalic acid, adipic acid, boric acid, orthophosphoric acid, phosphorous acid, hypophosphoric acid, metaboric acid, pyroboric acid, anhydrous zinc chloride, anhydrous aluminum chloride, anhydrous ferric chloride, anhydrous copper chloride, boron trifluoride diethyl ether complex, tin tetrachloride, titanium trichloride, and anhydrous cobalt chloride; the total mass of the aldehyde-amine monomer to the molar ratio of the proton acid is 100:1 to 5:1.

[0019] In step 3, solvent B is N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, hexamethylphosphoric triamine, acetone, butanone, cyclohexanone, methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, tert-butanol, ethylene glycol, propylene glycol, glycerol, deionized water, benzene, toluene, o-xylene, m-xylene, p-xylene, ethylbenzene, mesitylene, naphthane, chlorotoluene, dichlorobenzene. One or more of the following: methane, chloroform, carbon tetrachloride, 1,2-dichloroethane, 1,1,2-trichloroethane, chlorobenzene, o-dichlorobenzene, p-dichlorobenzene, tetrahydrofuran, 1,4-dioxane, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, isopropyl ether, n-butyl ether, and anisole; the mass ratio of the total amount of aldehyde monomers and ammonia monomers to solvent B is 1:5 to 1:500; the reaction temperature is 0 to 60℃, and the reaction time is 3 to 78 h.

[0020] In step 4, the ionic liquid is 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1-hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1-octyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1- One or more of the following: hexylpyridine bis(trifluoromethanesulfonyl)imide salt, 1-butylpyridine bis(fluoromethanesulfonyl)imide salt, 1-ethylpyridine tetrafluoroborate, 1-methyl-3-ethylpyrazolium bis(trifluoromethanesulfonyl)imide salt, 1,3-dimethylpyrazolium bis(fluoromethanesulfonyl)imide salt, 1-methyl-4-ethyl-1,2,4-triazolium bis(trifluoromethanesulfonyl)imide salt, 1,4-dimethyl-1,2,4-triazolium tetrafluoroborate, N-butyl-N-methylpyrrolidine lithium bis(trifluoromethanesulfonyl)imide salt, and 1-ethyl-3-methylimidazolium lithium bis(fluoromethanesulfonyl)imide salt; the volume of the ionic liquid solution is 0.1~10 mL.

[0021] In step 5, the mass concentration of the polyethylene oxide is 5-30%, the coating temperature is 0-150℃, the polyethylene oxide coating film formation rate is 5-50 mm / s, and the thickness of the resulting polyethylene oxide single surface layer is 5-50 μm.

[0022] In step 5, the electrolyte has a tensile strength of 13-24 MPa and a room temperature ionic conductivity of [missing value]. The maximum impedance over a wide temperature range is 6432~9621Ω, the coulombic efficiency of the battery is 97.2~99.1%, and the capacity retention rate after 120 cycles at -10℃ / 0.1C is 86.5~93.2%.

[0023] The present invention also provides a through-network structure functional fiber-based solid electrolyte obtained by the aforementioned preparation method. This material, as a solid electrolyte film layer with dual functions of ion conduction and mechanical support, is applied in a wide-temperature-range solid lithium-ion battery. It aims to solve the key problems of high interfacial impedance between solid electrolyte and positive and negative electrodes, rapid decay of low-temperature ion conductivity, and short circuit caused by lithium dendrite puncture during cycling by constructing a three-dimensional continuous ion transport network.

[0024] Beneficial effects: The beneficial effects of this invention are as follows: (1) By combining spinning technology with COF in-situ interfacial polycondensation, and using aldehyde-based fiber precursor as a template, a continuous self-supporting three-dimensional network structure of COF and ionic liquid integrated solid electrolyte was successfully constructed. It not only inherits the advantages of high specific surface area, regular channels and abundant active sites of COF materials, but also shortens the ion transport path by means of multi-channel structure, and achieves the unity of wide temperature range high ionic conductivity and excellent mechanical stability, effectively overcoming the bottlenecks of high crystallinity of traditional polyoxyethylene electrolytes, uneven dispersion of COF-based composite electrolytes and many interfacial defects. (2) The innovative step-by-step assembly strategy of first spinning aldehyde, then interfacial polycondensation to form a shell, then loading ionic liquid, and finally polyoxyethylene coating is adopted, which realizes the uniform and controllable growth of COF shell on the surface of fiber template and the tight combination of each component. The preparation process is controllable, has good repeatability, and is easy to scale up for industrial production. (3) Through the synergistic effect of COF channel confinement, the high ionic conductivity of ionic liquid and the mechanical support of polyethylene oxide coating, a multi-level ion transport system is formed, which significantly improves the wide temperature range adaptability, electrochemical cycle stability and ion transport efficiency of the composite solid electrolyte. (4) The composite solid electrolyte can effectively suppress lithium dendrite growth, avoid ionic liquid loss and phase separation, and has excellent compatibility with electrode materials. It is suitable for wide temperature range electrochemical energy storage scenarios of -40~150℃, providing reliable material support for the practical application of solid lithium batteries.

[0025] This invention proposes a wide-temperature-range high-stability COF and ionic liquid integrated solid electrolyte with a through-network structure. It features abundant ion transport sites, a multi-channel network structure, excellent mechanical strength, and wide-temperature-range adaptability. Under harsh electrochemical energy storage conditions such as extreme high and low temperatures, high voltage, and long cycles, it exhibits excellent stability and long-term operating potential. To address the problems of low room-temperature ionic conductivity, poor wide-temperature-range stability, lithium dendrite puncture, and easy loss of ionic liquid in the current solid-state lithium battery field, this invention provides an innovative composite solid electrolyte solution that is efficient, stable, and has industrial application potential. It has significant practical application value and industrialization prospects. Attached Figure Description

[0026] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, and the advantages of the present invention in the above and / or other aspects will become clearer.

[0027] Figure 1 This is a schematic diagram of the method flow of the present invention.

[0028] Figure 2 This is a scanning electron microscope image of the COF and ionic liquid integrated solid electrolyte in Example 1.

[0029] Figure 3This is the elemental distribution diagram of the COF and ionic liquid integrated solid electrolyte in Example 1.

[0030] Figure 4 This is the Fourier transform infrared spectrum of the COF and ionic liquid integrated solid electrolyte in Example 1.

[0031] Figure 5 This is a scanning electron microscope image of the COF and ionic liquid integrated solid electrolyte in Example 2.

[0032] Figure 6 This is a scanning electron microscope image of the COF and ionic liquid integrated solid electrolyte in Example 3.

[0033] Figure 7 This is a scanning electron microscope image of the COF and ionic liquid integrated solid electrolyte in Example 4. Detailed Implementation

[0034] like Figure 1As shown, Example 1 of the present invention provides a method for preparing a COF and ionic liquid integrated solid electrolyte, comprising the following steps: Step 11, preparing an aldehyde-containing functional spinning solution: polyacrylonitrile and terephthalaldehyde are co-dissolved in N,N-dimethylformamide to prepare an aldehyde-containing functional spinning solution (the mass fraction of polyacrylonitrile in the spinning solution is 15%, and the molar ratio of polyacrylonitrile to terephthalaldehyde is 5:1); Step 12, preparing an aldehyde-based fiber precursor: the aldehyde-containing functional spinning solution obtained in Step 11 is subjected to high-voltage electrospinning (spinning voltage is 25kV, feed rate is 1.5mL / h, spinning distance is 20cm, temperature is 40℃, and humidity is 40%). RH, reciprocating speed 3cm / min) to prepare aldehyde-based fiber precursor; Step 13, preparation of core-shell structured COF fiber membrane: using the aldehyde-based fiber precursor obtained from S12 as a template, fiber surface polymerization was induced in a system of p-phenylenediamine, p-toluenesulfonic acid and N,N-dimethylformamide (molar ratio of terephthalaldehyde to p-phenylenediamine was 1:1, molar ratio of the sum of terephthalaldehyde and p-phenylenediamine to p-toluenesulfonic acid was 20:1, mass ratio of the sum of terephthalaldehyde and p-phenylenediamine to N,N-dimethylformamide was 1:50; reaction temperature was 25℃, reaction time was 4 Step 14: Preparation of ionic liquid-functionalized COF fiber membrane: 2 mL of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt was loaded onto the surface of the core-shell COF fiber membrane obtained in step S13 to prepare an ionic liquid-functionalized COF fiber membrane. Step 15: Preparation of COF-ionic liquid integrated solid electrolyte: Polyethylene oxide (15% mass concentration, 60℃ coating temperature, 30 mm / s coating rate, and 25 μm thickness of a single polyethylene oxide layer) was coated onto the upper and lower surfaces of the ionic liquid-functionalized COF fiber membrane obtained in step S14 to prepare a COF-ionic liquid integrated solid electrolyte. The tensile strength of the obtained cross-network structure wide-temperature-range high-stability COF-ionic liquid integrated solid electrolyte is 24 MPa, and the room temperature ionic conductivity is [missing value]. The maximum impedance over a wide temperature range is 6432Ω, the battery coulombic efficiency is 99.1%, and the capacity retention rate is 93.2% after 120 cycles at -10℃ / 0.1C.

[0035] like Figure 2 As shown in the scanning electron microscope image of the COF and ionic liquid integrated solid electrolyte obtained in Example 1 of the present invention, the composite solid electrolyte uses electrospun fibers as templates and supports, while the COF functional layer is uniformly grown in situ on the fiber surface, the ionic liquid is uniformly coated on the fiber surface, and the polyethylene oxide is densely coated on the upper and lower surfaces of the fiber membrane without any surface defects.

[0036] Figure 3As shown in the figure, the elemental distribution diagram of the COF and ionic liquid integrated solid electrolyte obtained in Example 1 of the present invention shows that the characteristic elements such as carbon, oxygen, nitrogen, sulfur, lithium, and fluorine are densely and uniformly distributed on the electrolyte surface, indicating that each component is fully loaded and coated.

[0037] like Figure 4 As shown, the Fourier transform infrared spectrum of the COF-ionic liquid integrated solid electrolyte obtained in Example 1 of this invention indicates that the composite solid electrolyte structure contains -OH, -NH2, and The stretching vibration signal peaks of the bond and the sulfur-containing group representing COF and the fluorine-containing group representing ionic liquid.

[0038] Example 2 of this invention provides a method for preparing a COF-ion liquid integrated solid electrolyte, comprising the following steps: Step 21, preparing an aldehyde-containing functional spinning solution: polyacrylonitrile and isophthalaldehyde are co-dissolved in N,N-dimethylacetamide to prepare an aldehyde-containing functional spinning solution (the mass fraction of polyacrylonitrile in the spinning solution is 12%, and the molar ratio of polyacrylonitrile to isophthalaldehyde is 2:1); Step 22, preparing an aldehyde-based fiber precursor: the aldehyde-containing functional spinning solution obtained in step S21 is wet-spun (spinneret parameters are 0.2 mm, spinning temperature is 40 °C, spinning speed is 1.5 mL / min, draw ratio is 7 times, and winding speed is 300 m / min) to prepare an aldehyde-based fiber precursor; Step 23, preparing a core-shell structured COF fiber membrane: using the aldehyde-based fiber precursor obtained in step S22 as a template, fiber surface polymerization is induced in a system of m-phenylenediamine, benzenesulfonic acid, and N,N-dimethylacetamide (m-phenylenediamine, benzenesulfonic acid, and N,N-dimethylacetamide). The molar ratio of formaldehyde to m-phenylenediamine is 1:5, the molar ratio of the sum of m-phenylenediamine and m-phenylenediamine to benzenesulfonic acid is 10:1, and the mass ratio of the sum of m-phenylenediamine and m-phenylenediamine to N,N-dimethylacetamide is 1:20; the reaction temperature is 10℃ and the reaction time is 24h), to prepare a core-shell structured COF fiber membrane; Step 24, preparing an ionic liquid functionalized COF fiber membrane: 1 mL of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt is loaded onto the surface of the core-shell structured COF fiber membrane obtained in S23 to prepare an ionic liquid functionalized COF fiber membrane; Step 25, preparing a COF and ionic liquid integrated solid electrolyte: Polyethylene oxide is coated on the upper and lower surfaces of the ionic liquid functionalized COF fiber membrane obtained in S24 (the mass concentration of polyethylene oxide used is 10%, the coating temperature is 20℃, the polyethylene oxide coating film formation rate is 15 mm / s, and the thickness of the single polyethylene oxide surface layer is 10 mm). A COF-ionic liquid integrated solid electrolyte was prepared by (μm). The resulting COF-ionic liquid integrated solid electrolyte with a wide temperature range and high stability exhibited a tensile strength of 21 MPa and a room temperature ionic conductivity of [missing value]. The maximum impedance over a wide temperature range is 7034Ω, the battery coulombic efficiency is 98.4%, and the capacity retention rate is 91.1% after 120 cycles at -10℃ / 0.1C.

[0039] like Figure 5 As shown in the scanning electron microscope image of the COF and ionic liquid integrated solid electrolyte obtained in Example 2 of the present invention, the composite solid electrolyte uses electrospun fibers as templates and supports, while a COF functional layer is uniformly grown in situ on the fiber surface, the ionic liquid is uniformly coated on the fiber surface, and polyethylene oxide is densely coated on the upper and lower surfaces of the fiber membrane without any surface defects.

[0040] Example 3 of this invention provides a method for preparing a COF and ionic liquid integrated solid electrolyte, comprising the following steps: Step 31, preparing an aldehyde-containing functional spinning solution: polyacrylonitrile and trimesin are co-dissolved in N-methylpyrrolidone to prepare an aldehyde-containing functional spinning solution (the mass fraction of polyacrylonitrile in the spinning solution is 18%, and the molar ratio of polyacrylonitrile to trimesin is 10:1); Step 32, preparing an aldehyde-based fiber precursor: the aldehyde-containing functional spinning solution obtained in step S31 is subjected to... Dry spinning (spinneret orifice diameter 0.15 mm, feed rate 3 mL / h, effective spinning length 2.5 m, air velocity 1.0 m / s, draw ratio 5 times) was used to prepare aldehyde-based fiber precursors; Step 33: Preparation of core-shell structured COF fiber membranes: Using the aldehyde-based fiber precursor obtained in S32 as a template, fiber surface polymerization was induced in a system of 4,4'-biphenyldiamine, dodecylbenzenesulfonic acid, and acetone (molar ratio of pyromellitic methyl ester to 4,4'-biphenyldiamine). The mass ratio of the total of pyromellitic methyl methacrylate and 4,4'-biphenyl diamine to dodecylbenzenesulfonic acid was 40:1, and the molar ratio of the total of pyromellitic methyl methacrylate and 4,4'-biphenyl diamine to acetone was 1:100; the reaction temperature was 40℃ and the reaction time was 60h), to prepare a core-shell structured COF fiber membrane; Step 34, Preparation of ionic liquid functionalized COF fiber membrane: 3 mL of 1-ethyl-3-methylimidazolium chloride was loaded onto the surface of the core-shell structured COF fiber membrane obtained in S33. Azoxyl tetrafluoroborate was used to prepare an ionic liquid-functionalized COF fiber membrane; step 35, preparation of a COF-ionic liquid integrated solid electrolyte: Polyethylene oxide (20% mass concentration, 90℃ coating temperature, 40mm / s coating rate, and 30μm thickness of a single polyethylene oxide layer) was coated onto the upper and lower surfaces of the ionic liquid-functionalized COF fiber membrane obtained in step S34 to prepare the COF-ionic liquid integrated solid electrolyte. The maximum impedance over a wide temperature range is 8584Ω, the battery coulombic efficiency is 98.0%, and the capacity retention rate is 88.9% after 120 cycles at -10℃ / 0.1C.

[0041] like Figure 6 As shown in the scanning electron microscope image of the COF and ionic liquid integrated solid electrolyte obtained in Example 3 of the present invention, the composite solid electrolyte uses electrospun fibers as templates and supports, while the COF functional layer is uniformly grown in situ on the fiber surface, the ionic liquid is uniformly coated on the fiber surface, and the polyethylene oxide is densely coated on the upper and lower surfaces of the fiber membrane without any surface defects.

[0042] Example 4 of this invention provides a method for preparing a COF and ionic liquid integrated solid electrolyte, comprising the following steps: Step 41, preparing an aldehyde-containing functional spinning solution: polyacrylonitrile and 4,4'-bipyridinedicarboxaldehyde are co-dissolved in dichloromethane to prepare an aldehyde-containing functional spinning solution (the mass fraction of polyacrylonitrile in the spinning solution is 20%, and the molar ratio of polyacrylonitrile to 4,4'-bipyridinedicarboxaldehyde is 20:1); Step 42, preparing an aldehyde-based fiber precursor: the aldehyde-containing functional spinning solution obtained in step S41 is subjected to high-speed centrifugal spinning (spinning speed is 10000 rpm). The process involved preparing an aldehyde-based fiber precursor using a spinneret with a spinneret orifice diameter of 0.40 mm, a feed rate of 3.5 mL / h, and a spinning distance of 14 cm. Step 43: Preparation of a core-shell COF fiber membrane: Using the aldehyde-based fiber precursor obtained in S42 as a template, surface polymerization of the fiber was induced in a system of 1,3,5-triaminobenzene, acetic acid, and tetrahydrofuran (the molar ratio of 4,4'-bipyridinedicarboxaldehyde to 1,3,5-triaminobenzene was 5:1, the molar ratio of the sum of 4,4'-bipyridinedicarboxaldehyde and 1,3,5-triaminobenzene to acetic acid was 60:1, and the mass ratio of the sum of 4,4'-bipyridinedicarboxaldehyde and 1,3,5-triaminobenzene to tetrahydrofuran was 1:200; the reaction temperature was 60℃). The reaction time was 72 h), and a core-shell COF fiber membrane was prepared. Step 44: Preparation of ionic liquid-functionalized COF fiber membrane: 5 mL of 1,3-dimethylpyrazine-onium bisfluorosulfonylimide salt was loaded onto the surface of the core-shell COF fiber membrane obtained in step S43 to prepare an ionic liquid-functionalized COF fiber membrane. Step 45: Preparation of COF-ionic liquid integrated solid electrolyte: Polyethylene oxide (25% mass concentration, 120℃ coating temperature, 50 mm / s coating rate, and 50 μm thickness of a single polyethylene oxide layer) was coated onto the upper and lower surfaces of the ionic liquid-functionalized COF fiber membrane obtained in step S44 to prepare a COF-ionic liquid integrated solid electrolyte. The tensile strength of the obtained cross-network structure wide-temperature-range high-stability COF-ionic liquid integrated solid electrolyte was 13 MPa, and the room temperature ionic conductivity was [missing value]. The maximum impedance over a wide temperature range is 9621Ω, the battery coulombic efficiency is 97.2%, and the capacity retention rate is 86.5% after 120 cycles at -10℃ / 0.1C.

[0043] like Figure 7 As shown in the scanning electron microscope image of the COF and ionic liquid integrated solid electrolyte obtained in Example 4 of the present invention, the composite solid electrolyte uses electrospun fibers as templates and supports, while the COF functional layer is uniformly grown in situ on the fiber surface, the ionic liquid is uniformly coated on the fiber surface, and the polyethylene oxide is densely coated on the upper and lower surfaces of the fiber membrane without any surface defects.

[0044] Comparative Example 1 of this invention provides a method for preparing a COF-ionic liquid integrated solid electrolyte, which is basically prepared using the method of Example 1. The difference is that in this example, the aldehyde-containing monomer and polyacrylonitrile were not mixed beforehand to prepare the aldehyde-containing functional spinning solution and the aldehyde-based fiber precursor. Specifically, a polyacrylonitrile spinning solution was prepared by dissolving polyacrylonitrile in N,N-dimethylformamide (the mass fraction of polyacrylonitrile in the spinning solution was 15%). The obtained polyacrylonitrile spinning solution was then subjected to high-voltage electrospinning (spinning voltage 25 kV, feed rate 1.5 mL / h, spinning distance 20 cm, temperature 40 °C, humidity 40% RH, reciprocating speed 3 cm / min) to prepare a fiber precursor membrane. Using the obtained fiber precursor membrane as a template, fiber surface polymerization was induced in a system of terephthalaldehyde, p-phenylenediamine, p-toluenesulfonic acid, and N,N-dimethylformamide (the molar ratio of terephthalaldehyde to p-phenylenediamine was 1:1, and the molar ratio of the sum of terephthalaldehyde and p-phenylenediamine to p-toluenesulfonic acid was 20). 1. A core-shell COF fiber membrane was prepared by reacting terephthalaldehyde and p-phenylenediamine in a mass ratio of 1:50 to N,N-dimethylformamide at a reaction temperature of 25℃ for 48 h. 2 mL of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt was loaded onto the surface of the obtained core-shell COF fiber membrane to prepare an ionic liquid-functionalized COF fiber membrane. Polyethylene oxide (15% mass concentration, 60℃ coating temperature, 30 mm / s coating rate, and 25 μm thickness of a single polyethylene oxide layer) was coated onto the upper and lower surfaces of the obtained ionic liquid-functionalized COF fiber membrane to prepare a COF-ionic liquid integrated solid electrolyte. The tensile strength of the obtained wide-temperature-range, high-stability COF-ionic liquid integrated solid electrolyte with a through-network structure was 4 MPa, and the room temperature ionic conductivity was [missing value]. The maximum impedance over a wide temperature range is 15349Ω, the battery coulombic efficiency is 90.8%, and the capacity retention rate is 72.3% after 120 cycles at -10℃ / 0.1C.

[0045] Comparative Example 2 of this invention provides a method for preparing a COF-ionic liquid integrated solid electrolyte, which basically adopts the method of Example 2. The difference is that this example does not use ionic liquid for fiber surface loading. Specifically, polyacrylonitrile and isophthalaldehyde are co-dissolved in N,N-dimethylacetamide to prepare an aldehyde-containing functional spinning solution (the mass fraction of polyacrylonitrile in the spinning solution is 12%, and the molar ratio of polyacrylonitrile to isophthalaldehyde is 2:1); the obtained aldehyde-containing functional spinning solution is used to prepare an aldehyde-based fiber precursor by wet spinning (spinneret parameters are 0.2 mm, spinning temperature is 40℃, spinning speed is 1.5 mL / min, draw ratio is 7 times, and winding speed is 300 m / min); using the obtained aldehyde-based fiber precursor as a template, fiber surface polymerization is induced in a system of m-phenylenediamine, benzenesulfonic acid, and N,N-dimethylacetamide (isophthalaldehyde... A core-shell COF fiber membrane was prepared by reacting aldehydes and m-phenylenediamine in a molar ratio of 1:5, the total molar ratio of m-phenylenedialdehyde and m-phenylenediamine to benzenesulfonic acid in a molar ratio of 10:1, and the total mass ratio of m-phenylenedialdehyde and m-phenylenediamine to N,N-dimethylacetamide in a mass ratio of 1:20 (reaction temperature: 10℃, reaction time: 24h). Polyethylene oxide (PEO) was then coated onto the upper and lower surfaces of the obtained COF fiber membrane (PEO mass concentration: 10%, coating temperature: 20℃, PEO coating film formation rate: 15mm / s, resulting in a single PEO surface layer thickness of 10μm). This process was used to prepare a COF-ionic liquid integrated solid electrolyte. The resulting cross-network structure, with its wide temperature range and high stability, exhibited a tensile strength of 3MPa and a room temperature ionic conductivity of [missing value]. The maximum impedance over a wide temperature range is 17616Ω, the battery coulombic efficiency is 87.6%, and the capacity retention rate is 70.1% after 120 cycles at -10℃ / 0.1C.

[0046] Comparative Example 3 of this invention provides a method for preparing a COF-ionic liquid integrated solid electrolyte, which basically adopts the method of Example 3. The difference is that this example does not perform in-situ uniform growth of the COF functional layer, but directly uses a polyacrylonitrile electrospun fiber membrane for surface ionic liquid loading and polyethylene oxide coating. Specifically, a polyacrylonitrile spinning solution was prepared by dissolving polyacrylonitrile in N-methylpyrrolidone (the mass fraction of polyacrylonitrile in the spinning solution was 18%). The obtained polyacrylonitrile spinning solution was then used to prepare a polyacrylonitrile fiber precursor membrane by dry spinning (spinneret orifice diameter of 0.15 mm, feed rate of 3 mL / h, effective spinning length of 2.5 m, air velocity of 1.0 m / s, and draw ratio of 5). 3 mL of 1-ethyl-3-methylimidazolium tetrafluoroborate was loaded onto the surface of the obtained polyacrylonitrile fiber precursor membrane to prepare an ionic liquid functionalized fiber membrane. Polyethylene oxide (the mass concentration of polyethylene oxide used was 20%, the coating temperature was 90 °C, the polyethylene oxide coating film formation rate was 40 mm / s, and the thickness of the single polyethylene oxide surface layer was 30 μm) was coated onto the upper and lower surfaces of the obtained ionic liquid functionalized fiber membrane to prepare an ionic liquid composite solid electrolyte. The obtained cross-network structure, with its wide-temperature-range high stability, integrates a COF with an ionic liquid to form a solid electrolyte with a tensile strength of 3 MPa and a room-temperature ionic conductivity of [missing value]. The maximum impedance over a wide temperature range is 19923 Ω, the battery coulombic efficiency is 84.1%, and the capacity retention rate is 67.9% after 120 cycles at -10℃ / 0.1C.

[0047] The structural characterization and performance testing are as follows.

[0048] Scanning electron microscopy observation: The microstructure of the COF-ionic liquid integrated solid electrolyte was observed using a field emission scanning electron microscope (model JSM-7900F, NEC). Figure 2 , Figure 5 , Figure 6 , Figure 7 ).

[0049] Surface elemental distribution testing: The surface elemental distribution of the COF / ionic liquid integrated solid electrolyte was recorded using an energy-dispersive X-ray spectrometer (Vario EL, NEC). Figure 3 ).

[0050] Functional group structure testing: The functional groups of the COF-ionic liquid integrated solid electrolyte were recorded using an infrared spectrometer (VERTEX 70, Bruker, USA). Figure 4 ).

[0051] Mechanical property testing: The tensile strength of the COF and ionic liquid integrated solid electrolyte was recorded using a universal testing machine (model GT-7010, China High-speed Railway Testing Instrument Co., Ltd.).

[0052] Electrochemical performance testing: The room temperature ionic conductivity, impedance, coulombic efficiency, and capacity retention of the COF-ion liquid integrated solid electrolyte were recorded using an electrochemical workstation (model CHI660F, Huachen, China).

[0053] Experimental results: such as Figure 2 , Figure 5 , Figure 6 and Figure 7 As shown, the obtained COF and ionic liquid integrated solid electrolyte uses electrospun fibers as templates and supports. At the same time, a COF functional layer is uniformly grown in situ on the fiber surface, the ionic liquid is uniformly coated on the fiber surface, and polyethylene oxide is densely coated on the upper and lower surfaces of the fiber membrane without any surface defects.

[0054] like Figure 3 As shown, the characteristic elements such as carbon, oxygen, nitrogen, sulfur, lithium, and fluorine of the obtained COF-ion liquid integrated solid electrolyte are densely and uniformly distributed on the electrolyte surface, indicating that each component is fully loaded and coated, and that the components in the composite solid electrolyte have good structural matching and achieve functional integration.

[0055] like Figure 4 As shown, the obtained COF integrated with the ionic liquid solid electrolyte structure contains -OH, -NH2, and The stretching vibration signal peaks of the bonds and the sulfur-containing groups representing COF and the fluorine-containing groups representing ionic liquids confirm the successful introduction of each component into the solid composite electrolyte.

[0056] Table 1 compares the tensile strength, room temperature ionic conductivity, maximum impedance over a wide temperature range, battery coulombic efficiency, and capacity retention after -10℃ / 0.1C / 120 cycles of the COF-ion liquid integrated solid electrolyte obtained in the examples and comparative examples.

[0057]

[0058] Table 1

[0059] Examples 1-4 exhibit high tensile strength (13-24 MPa) and fast room-temperature ionic conductivity (0.21-0.42 mS·cm⁻). 1The membrane exhibits a low maximum impedance over a wide temperature range (6432~9621Ω) because the aldehyde-containing monomers are pre-dispersed uniformly and precisely within the fiber through spinning. During COF growth, the precise bonding and crystallization of the aldehyde-containing and ammonia-containing monomers promotes uniform and controllable in-situ growth. Furthermore, the fiber membrane surface is loaded with ionic liquid and uniformly coated with polyethylene oxide on both the upper and lower surfaces, resulting in stable tensile strength and excellent ionic conductivity and impedance. In contrast, the tensile strength of comparative examples 1-3 is only 3-4 MPa, and the room temperature ionic conductivity is... The maximum impedance over a wide temperature range is 15349~19923Ω. This is because the in-situ growth process and method of COF were not effectively controlled, making it impossible to achieve controllable Schiff base condensation. At the same time, ionic liquid loading and polyethylene oxide coating were not carried out.

[0060] The coulombic efficiency and capacity retention after -10℃ / 0.1C / 120 cycles of the COF-ion liquid integrated solid electrolyte battery are related to tensile strength, room temperature ionic conductivity, and maximum impedance over a wide temperature range. The batteries in Examples 1-4, which have high tensile strength, fast room temperature ionic conductivity, and low maximum impedance over a wide temperature range, all have a coulombic efficiency of over 97.2% and a capacity retention after -10℃ / 0.1C / 120 cycles of over 86.5%, demonstrating good battery capacity and a wide temperature range interconnected network. Among them, Example 1, which has the highest tensile strength, fastest room temperature ionic conductivity, and widest temperature range maximum impedance, performed best in battery tests under extreme high and low temperature environments. The battery coulombic efficiency was 99.1%, and the capacity retention rate after -10℃ / 0.1C / 120 cycles was 93.2%, which is much higher than Comparative Examples 1 to 3 (battery coulombic efficiency ≤90.8%, capacity retention rate after -10℃ / 0.1C / 120 cycles ≤72.3%), which have low tensile strength, slow room temperature ionic conductivity, and relatively high wide temperature range maximum impedance.

[0061] This invention provides a method for preparing a wide-temperature-range, high-safety, through-network structure functional fiber-based solid electrolyte. Many methods and approaches exist for implementing this technical solution; the above description is merely a preferred embodiment of the invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications should also be considered within the scope of protection of this invention. All components not explicitly stated in this embodiment can be implemented using existing technologies.

Claims

1. A method for preparing a wide-temperature-range, high-safety through-network structure functional fiber-based solid electrolyte, characterized in that, Includes the following steps: Step 1: Prepare an aldehyde-containing functional spinning solution by co-dissolving polyacrylonitrile and aldehyde-containing monomers in solvent A; Step 2: Prepare aldehyde-based fiber precursors from the spinning solution obtained in Step 1; Step 3: Using the aldehyde-modified fiber precursor obtained in Step 2 as a template, induce fiber surface polymerization in a system containing ammonia monomer, proton source and solvent B to prepare a core-shell structured COF fiber membrane. Step 4: Load ionic liquid onto the surface of the core-shell COF fiber membrane obtained in Step 3 to prepare an ionic liquid functionalized COF fiber membrane; Step 5: Coat the upper and lower surfaces of the ionic liquid-functionalized COF fiber membrane obtained in Step 4 with polyethylene oxide to prepare a solid electrolyte with an integrated COF and ionic liquid through-network structure.

2. The method according to claim 1, characterized in that, In step 1, the aldehyde-containing monomer is terephthalaldehyde, isophthalaldehyde, o-phthalaldehyde, trimesonaldehyde, pyromellitic terephthalaldehyde, 2,5-dihydroxyterephthalaldehyde, 2-fluoroterephthalaldehyde, 2-chloroterephthalaldehyde, 4-hydroxyimolecular diphthalaldehyde, 2,4,6-trihydroxytrisonesonaldehyde, 4,4'-biphenyldiphthalaldehyde, 4,4''-triphenyldiphthalaldehyde, or 2,5-dimethoxyterephthalaldehyde. One or more of the following: 2-amino-terephthalaldehyde, 1,4-naphthalenedicarboxyl, 2,6-naphthalenedicarboxyl, 2,6-pyridinedicarboxaldehyde, 2,5-furandicarboxaldehyde, 3,6-carbazoledicarboxaldehyde, 2,3-pyrazinedicarboxaldehyde, 4,4'-bipyridinedicarboxaldehyde, 2,6-quinolinedicarboxaldehyde, 1,3,6,8-pyrenetetracarboxaldehyde, 9,10-anthracenedicarboxaldehyde, glyoxal, succinaldehyde, and glutaraldehyde.

3. The method according to claim 2, characterized in that, In step 1, solvent A is N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, N-ethylpyrrolidone, hexamethylphosphoric triamine, sulfolane, dimethyl sulfone, cyclohexanone, methyl isobutyl ketone, dichloromethane, chloroform, 1,2-dichloroethane, tetrahydrofuran, acetone, butanone, or ethyl acetate. The mass fraction of polyacrylonitrile in the spinning solution is 5-25%, and the molar ratio of polyacrylonitrile to aldehyde-containing monomer is 50:1-1:

1.

4. The method according to claim 3, characterized in that, In step 2, the spinning method is one or more of the following: high-voltage electrospinning, ultrasonic-assisted electrospinning, magnetic field-assisted electrospinning, electric field-controlled directional electrospinning, airflow-assisted electrospinning, coaxial electrospinning, emulsion electrospinning, phase separation electrospinning, melt electrospinning, wet spinning, dry spinning, dry-jet wet spinning, gel spinning, high-speed centrifugal spinning, ultrasonic-assisted centrifugal spinning, airflow-assisted centrifugal spinning, electro-jet spinning, electrostatic-centrifugal composite spinning, microfluidic spinning, meltblown spinning, and twin-screw extrusion spinning.

5. The method according to claim 4, characterized in that, In step 3, the ammonia-containing monomer is p-phenylenediamine, m-phenylenediamine, o-phenylenediamine, 4,4'-biphenylenediamine, 3,3'-biphenylenediamine, 2,2'-biphenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 2,2'-diaminodiphenyl sulfone, o-toluidine, m-toluidine, or 2,2'-dimethylbenzene. -4,4'-Biphenyldiamine, 1,4-naphthyldiamine, 1,5-naphthyldiamine, 2,6-naphthyldiamine, 2,7-naphthyldiamine, 9,10-anthraphthalenediamine, 4,4'-diaminodiphenyl sulfide, 1,3,5-triaminobenzene, 2,4,6-triaminotoluene, 2,4,6-triaminoresorcinol, 1,3,5-triamino-2,4,6-trimethylbenzene, 1,2,4,5-tetraaminobenzene, 3,3 ',5,5'-Tetraaminobiphenyl, 5,10,15,20-Tetraaminophenylporphyrin, Tetraaminophthalocyanine copper, 2,6-Diaminopyridine, 2,4-Diaminopyridine, 3,5-Diaminopyridine, 2,3-Diaminopyrazine, 2,5-Diaminopyrazine, 2,6-Diaminopyrimidine, 4,5-Diaminoimidazolium, 2,4-Diaminoimidazolium, 2,5-Diaminothiophene, 3,4-Diaminothiophene One or more of the following: 2,5-diaminofuran, 3,6-diaminocarbazole, 2,7-diaminofluorene, 9,9-dimethyl-2,7-diaminofluorene, 2,4-diaminopyrimidine, 5,6-diaminopyrimidine, 1,3,6,8-tetraaminopyrene, 2,3,6,7-tetraaminoanthracene, and 1,4,5,8-tetraaminonaphthalene; wherein the molar ratio of the aldehyde monomer to the ammonia monomer is 10:1 to 1:

10.

6. The method according to claim 5, characterized in that, In step 3, the proton source is one or more of the following: p-toluenesulfonic acid, benzenesulfonic acid, methanesulfonic acid, trifluoromethanesulfonic acid, dodecylbenzenesulfonic acid, aminosulfonic acid, camphorsulfonic acid, styrenesulfonic acid, naphthalenesulfonic acid, m-methylbenzenesulfonic acid, p-chlorobenzenesulfonic acid, o-nitrobenzenesulfonic acid, formic acid, acetic acid, propionic acid, benzoic acid, o-hydroxybenzoic acid, m-hydroxybenzoic acid, p-hydroxybenzoic acid, trifluoroacetic acid, trichloroacetic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, citric acid, tartaric acid, maleic acid, fumaric acid, pyromellitic acid, terephthalic acid, adipic acid, boric acid, orthophosphoric acid, phosphorous acid, hypophosphoric acid, metaboric acid, pyroboric acid, anhydrous zinc chloride, anhydrous aluminum chloride, anhydrous ferric chloride, anhydrous copper chloride, boron trifluoride diethyl ether complex, tin tetrachloride, titanium trichloride, and anhydrous cobalt chloride; the total mass of the aldehyde-amine monomer to the molar ratio of the proton acid is 100:1 to 5:

1.

7. The method according to claim 6, characterized in that, In step 3, solvent B is N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, hexamethylphosphoric triamine, acetone, butanone, cyclohexanone, methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, tert-butanol, ethylene glycol, propylene glycol, glycerol, deionized water, benzene, toluene, o-xylene, m-xylene, p-xylene, ethylbenzene, mesitylene, naphthane, chlorotoluene, dichlorobenzene. One or more of the following: methane, chloroform, carbon tetrachloride, 1,2-dichloroethane, 1,1,2-trichloroethane, chlorobenzene, o-dichlorobenzene, p-dichlorobenzene, tetrahydrofuran, 1,4-dioxane, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, isopropyl ether, n-butyl ether, and anisole; the mass ratio of the total amount of aldehyde monomers and ammonia monomers to solvent B is 1:5 to 1:500; the reaction temperature is 0 to 60℃, and the reaction time is 3 to 78 h.

8. The method according to claim 7, characterized in that, In step 4, the ionic liquid is 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1-hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1-octyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1- One or more of the following: hexylpyridine bis(trifluoromethanesulfonyl)imide salt, 1-butylpyridine bis(fluoromethanesulfonyl)imide salt, 1-ethylpyridine tetrafluoroborate, 1-methyl-3-ethylpyrazolium bis(trifluoromethanesulfonyl)imide salt, 1,3-dimethylpyrazolium bis(fluoromethanesulfonyl)imide salt, 1-methyl-4-ethyl-1,2,4-triazolium bis(trifluoromethanesulfonyl)imide salt, 1,4-dimethyl-1,2,4-triazolium tetrafluoroborate, N-butyl-N-methylpyrrolidine lithium bis(trifluoromethanesulfonyl)imide salt, and 1-ethyl-3-methylimidazolium lithium bis(fluoromethanesulfonyl)imide salt; the volume of the ionic liquid solution is 0.1~10 mL.

9. The method according to claim 1, characterized in that, In step 5, the mass concentration of the polyethylene oxide is 5-30%, the coating temperature is 0-150℃, the polyethylene oxide coating film formation rate is 5-50 mm / s, and the thickness of the resulting polyethylene oxide single surface layer is 5-50 μm.

10. The method according to any one of claims 1 to 9, characterized in that, In step 5, the electrolyte has a tensile strength of 13-24 MPa and a room temperature ionic conductivity of [missing value]. The maximum impedance over a wide temperature range is 6432~9621Ω, the coulombic efficiency of the battery is 97.2~99.1%, and the capacity retention rate after 120 cycles at -10℃ / 0.1C is 86.5~93.2%.

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