Twisted structure imidazole high temperature proton exchange membrane and preparation method thereof

Abstract

The application belongs to the technical field of proton exchange membrane fuel cells, and discloses an imidazole high-temperature proton exchange membrane with a twisted structure and a preparation method thereof. One of 1-methyl-1H imidazole-2-formaldehyde, 1-ethyl-1H imidazole-2-formaldehyde, 1-propyl-1H imidazole-2-formaldehyde, 1-butyl-1H imidazole-2-formaldehyde, tetramethyl tetrahydro-spirobi[indane]-diol, trifluoroacetic acid and trifluoromethane sulfonic acid is used as catalysis, and a copolymer is synthesized by polycondensation, so that a full-carbon skeleton aromatic polymer with a spiro twisted microporous structure is obtained, and a copolymer membrane material is obtained. The copolymer membrane material is doped with phosphoric acid. The application has low preparation cost, mild reaction condition, compact or dense structure of the membrane material, transparency, uniformity and density, and good electric conductivity and mechanical properties.

Description

Technical Field

[0001] This invention relates to the field of proton exchange membrane fuel cell technology, and in particular to a twisted imidazole-based high-temperature proton exchange membrane and its preparation method. Background Technology

[0002] Proton exchange membrane fuel cells (PEMFCs) are highly efficient energy conversion devices that use polymer membranes as electrolytes to achieve direct conversion of chemical energy into electrical energy. They are now widely used in electric vehicles, stationary power stations, and other fields. Traditional proton exchange membrane materials (such as perfluorosulfonic acid membranes, typically represented by the Nafion series) possess excellent proton conductivity at low temperatures, but their proton conduction process is highly dependent on the aqueous environment, which typically limits the operating temperature of the devices to below 80°C. This deficiency not only causes a sharp decline in the membrane's proton conductivity at high temperatures but also easily leads to a series of problems such as catalyst poisoning and increased difficulty in hydrothermal management.

[0003] In recent years, phosphate-doped polymer electrolyte membranes have become a research hotspot due to their ability to maintain high proton conductivity in anhydrous environments, with polymer-phosphate composite systems containing basic functional groups attracting particular attention. For example, Wang Ailian et al. pointed out in "Research Progress of Polybenzimidazole / Phosphoric Acid Doped High-Temperature Proton Exchange Membranes" (2024, 37(2):137-149.DOI:10.14028 / j.cnki.1003-3726.2024.23.165) that the proton conduction mechanism of polybenzimidazole (PBI) membranes is as follows: the amide group on the imidazole ring acts as a proton acceptor, and proton migration is completed through the interaction between the NH bond of the imidazole ring and the phosphate ion. However, PBI-based membrane materials suffer from bottlenecks such as complicated preparation processes and high production costs. Therefore, developing low-cost, high-performance electrolyte membranes that can operate stably under anhydrous conditions above 100℃ has become an important research direction in this field. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a twisted imidazole-based high-temperature proton exchange membrane and its preparation method. This twisted imidazole-based high-temperature proton exchange membrane contains a full-carbon skeleton aromatic polymer with a spirocyclic twisted microporous structure. The introduction of imidazole groups not only endows the polymer with abundant proton binding sites, but also induces a highly twisted conformation through the rigid heterocyclic structure and the steric hindrance effect of the bisphenol monomer. This twisted conformation induced by the synergistic effect of electronic conjugation and steric hindrance of imidazole groups breaks the planar tendency of conventional imidazole polymers, possessing a triple uniqueness of structural scarcity, unique regulation, and performance-driven characteristics, resulting in a completely amorphous microstructure. This unique imidazole basic group and unique twisted structure exhibit ultra-high phosphoric acid binding and adsorption capacity. This structural feature significantly increases the phosphoric acid doping amount (ADC reaches 272.6% at 80℃, ADL reaches 11.1), thereby bringing superior proton conductivity (up to 89 mS / cm at 180℃). Meanwhile, the synergistic effect of the twisted structure and imidazole groups allows the mechanical properties required for HT-PEMFC applications to be maintained even when tensile strength decreases due to phosphoric acid plasticization. This combination of high proton conductivity and good mechanical stability provides a novel structural approach for the design of high-temperature proton exchange membrane materials. It enables these materials to possess good proton conductivity and mechanical stability under high-temperature conditions, making them suitable for high-temperature proton exchange membrane fuel cells.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a twisted imidazole-based high-temperature proton exchange membrane, with the following general structural formula:

[0006] or or

[0007] or ;

[0008] In the general formula, n is a positive integer.

[0009] The preparation method of a twisted imidazole-based high-temperature proton exchange membrane includes the following steps:

[0010] Step 1: Mix one of 1-methyl-1H imidazol-2-carboxaldehyde, 1-ethyl-1H imidazol-2-carboxaldehyde, 1-propyl-1H imidazol-2-carboxaldehyde, 1-butyl-1H imidazol-2-carboxaldehyde, tetramethyltetrahydro-spirodi[indane]-diol with a polar organic solvent to obtain a reactant solution;

[0011] Step 2: Add trifluoroacetic acid and trifluoromethanesulfonic acid to the reactant solution to carry out the reaction. After precipitation, wash and dry the precipitate to obtain the copolymer.

[0012] Step 3: Prepare a copolymer membrane material from the copolymer polymer;

[0013] Step 4: Dope the copolymer membrane material with phosphoric acid to obtain a twisted structure imidazole-based high-temperature proton exchange membrane.

[0014] In step 1, the polar organic solvent is dichloromethane;

[0015] In step 1, the molar ratio of one of 1-methyl-1H imidazol-2-carboxaldehyde, 1-ethyl-1H imidazol-2-carboxaldehyde, 1-propyl-1H imidazol-2-carboxaldehyde, and 1-butyl-1H imidazol-2-carboxaldehyde to tetramethyltetrahydro-spirodi[indane]-diol is 1.15:1.

[0016] In step 2, the ratio of trifluoroacetic acid to tetramethyltetrahydro-spirodi[indane]-diol added in step 1 is (0.6-0.7) mL:1g, and the ratio of trifluoromethanesulfonic acid to tetramethyltetrahydro-spirodi[indane]-diol added in step 1 is (1.2-1.4) mL:1g.

[0017] In step 2, the reaction temperature is 10℃-30℃ and the reaction time is 30min.

[0018] Step 3 specifically involves: dissolving the copolymer in N,N-dimethylacetamide to prepare a copolymer solution; pouring the copolymer solution into a petri dish, evaporating the solvent until dry, peeling the membrane off the petri dish, washing and drying to obtain a uniform and transparent copolymer membrane material.

[0019] In step 3, the copolymer is dissolved in N,N-dimethylacetamide at 75℃~85℃; the concentration of the copolymer solution is 2wt%-4wt%.

[0020] The solvent evaporation temperature is 80℃.

[0021] In step 4, the concentration of the phosphoric acid aqueous solution used for phosphoric acid doping is 85wt%, and the phosphoric acid doping soaking time is 24h~72h; the phosphoric acid doping amount of the distorted imidazole high-temperature proton exchange membrane is 122wt%~272wt%.

[0022] In summary, the present invention has the following beneficial effects:

[0023] 1. Raw materials are readily available and inexpensive: High-temperature proton exchange membranes based on tetramethyltetrahydro-spirodi[indane]-diol-methylimidazolium formaldehyde have a wide range of raw material sources, simple preparation process, and are suitable for large-scale industrial production.

[0024] 2. Excellent high-temperature proton conductivity: The imidazole-based high-temperature proton exchange membrane with a twisted structure prepared by pyridine group copolymerization modification and phosphoric acid doping can maintain high proton conductivity even under high temperature (100℃~180℃) without humidification. The conductivity at 180℃ can reach up to 89mS / cm.

[0025] 3. Good stability of membrane materials: Membrane materials modified with pyridine groups exhibit good mechanical and dimensional stability, and can maintain a low volume swelling rate and good flexibility under high temperature conditions.

[0026] 4. Adjustable doping content: By adjusting the temperature during the phosphoric acid doping process, different phosphoric acid doping amounts (122wt%~272wt%) can be achieved in the film material, thereby meeting the application requirements of different proton conductivity performance. Attached Figure Description

[0027] Figure 1 This is a comparison chart of the mass swelling, area swelling, and volume swelling of the copolymer films prepared in Examples 1 and 2;

[0028] Figure 2 Comparison of the mechanical properties of the phosphoric acid-doped high-temperature proton exchange membranes prepared in Examples 1 and 2;

[0029] Figure 3 A comparison of the conductivity of the phosphoric acid-doped high-temperature proton exchange membranes prepared in Examples 1 and 2 at different temperatures;

[0030] Figure 4 The above are the 1H NMR spectra of the copolymers prepared in Examples 1 and 2.

[0031] Figure 5 This is a spatial structure model of the copolymers prepared in Examples 1 and 2. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] The preparation of the high-temperature proton exchange membrane with a twisted structure according to the present invention includes the following steps:

[0034] Step 1: Preparation of reactant solution: Mix one of 1-methyl-1H imidazol-2-carboxaldehyde, 1-ethyl-1H imidazol-2-carboxaldehyde, 1-propyl-1H imidazol-2-carboxaldehyde, 1-butyl-1H imidazol-2-carboxaldehyde, tetramethyltetrahydro-spirodi[indane]-diol with a polar organic solvent at 10℃-30℃ to obtain reactant solution;

[0035] In this step, the polar organic solvent is dichloromethane, and one of 1-methyl-1H imidazol-2-carboxaldehyde, 1-ethyl-1H imidazol-2-carboxaldehyde, 1-propyl-1H imidazol-2-carboxaldehyde, and 1-butyl-1H imidazol-2-carboxaldehyde, and tetramethyltetrahydro-spirodi[indane]-diol are used as comonomers. The concentration of tetramethyltetrahydro-spirodi[indane]-diol in the reactant solution is 20wt%-30wt%, and the molar ratio of one of 1-methyl-1H imidazol-2-carboxaldehyde, 1-ethyl-1H imidazol-2-carboxaldehyde, 1-propyl-1H imidazol-2-carboxaldehyde, and 1-butyl-1H imidazol-2-carboxaldehyde to tetramethyltetrahydro-spirodi[indane]-diol is 1.15:1.

[0036] Step 2, Copolymerization Modification: Trifluoroacetic acid and trifluoromethanesulfonic acid were added to the reactant solution as catalysts. The mixture was stirred at 10℃-30℃ for 30 min. After the reaction, it was cooled to room temperature, and the reactant solution was poured into a sodium bicarbonate solution to precipitate flocculent fibers. After standing, the fibers were separated, washed, and dried to obtain the copolymer. The ratio of trifluoroacetic acid to tetramethyltetrahydro-spirodi[indane]-diol added in Step 1 was (0.6-0.7) mL:1g, and the ratio of trifluoromethanesulfonic acid to tetramethyltetrahydro-spirodi[indane]-diol added in Step 1 was (1.2-1.4) mL:1g.

[0037] Step 3: Preparation of copolymer membrane material: Dissolve the copolymer in N,N-dimethylacetamide (DMAC) at 75℃~85℃ to prepare a homogeneous copolymer solution of 2wt%-4wt%; pour the copolymer solution into a Teflon petri dish, place it in an oven at 80℃ to evaporate the solvent until dry, then peel the membrane off from the petri dish, wash and dry to obtain a homogeneous and transparent copolymer membrane material;

[0038] Step 4, Phosphoric acid doping: Under room temperature conditions, the copolymer membrane material prepared in step 3 is immersed in an 85wt% phosphoric acid aqueous solution for 24h~72h to dope with phosphoric acid, resulting in a twisted imidazole high-temperature proton exchange membrane with a phosphoric acid doping amount of 122wt%~272wt%.

[0039] The general formula for the resulting twisted imidazole-based high-temperature proton exchange membrane structure is as follows:

[0040] or or

[0041] or ;

[0042] In the general formula, n is a positive integer.

[0043] The preferred embodiments are as follows:

[0044] Example 1

[0045] At 20°C, 7.71 g of tetramethyltetrahydro-spirodi[indane]-diol (25 mmol) and 3.19 g of 1-methyl-1H-imidazol-2-carboxaldehyde (28.75 mmol) were added to 40 mL of dichloromethane at a molar ratio of tetramethyltetrahydro-spirodi[indane]-diol: 1:1.15, and stirred until homogeneous. After cooling the flask in an ice bath, 5 mL of trifluoroacetic acid was added dropwise with constant stirring. After stirring for 10 min, 10 mL of trifluoromethanesulfonic acid was added, and the reaction was stirred at room temperature for 20 min. The reaction solution was then cooled to room temperature and slowly poured into an aqueous sodium bicarbonate solution to precipitate flocculent fibers. After standing, the flocculent fibers were discharged and washed three times with deionized water. After thorough washing, the mixture was dried for 12 hours to obtain the copolymer. At 80°C, the copolymer was dissolved in DMAC using magnetic stirring to form... A 2.0 wt% copolymer solution was prepared. After obtaining a homogeneous solution, the membrane material was prepared by solution casting, i.e., the obtained copolymer solution was cast onto a Teflon petri dish, and then the solvent was evaporated in an 80°C oven until completely evaporated. The membrane was then peeled off from the petri dish, thoroughly washed with deionized water, and further dried to obtain a homogeneous and transparent copolymer membrane material. The obtained membrane was immersed in an 85 wt% phosphoric acid aqueous solution at 30°C for 24 hours to obtain a high-temperature proton exchange membrane with a phosphoric acid doping content of 122 wt%. The conductivity of this high-temperature proton exchange membrane material at 180°C without humidification was 27.4 mS / cm.

[0046] Example 2

[0047] At 20°C, 7.71 g of tetramethyltetrahydro-spirodiol (25 mmol) and 3.19 g of 1-methyl-1H-imidazol-2-carboxaldehyde (28.75 mmol) were added to 40 mL of dichloromethane at a molar ratio of tetramethyltetrahydro-spirodiol : 1:1.15, and stirred until homogeneous. After cooling the flask in an ice bath, 5 mL of trifluoroacetic acid was added dropwise with constant stirring. After stirring for 10 min, 10 mL of trifluoromethanesulfonic acid was added, and the reaction was stirred at room temperature for 20 min. The reaction solution was then cooled to room temperature and slowly poured into an aqueous sodium bicarbonate solution to precipitate flocculent fibers. After standing, the flocculent fibers were discharged and washed three times with deionized water. After thorough washing... The copolymer was dried for 12 hours to obtain a copolymer. The copolymer was dissolved in DMAC at 80°C using magnetic stirring to form a 2.0 wt% copolymer solution. After obtaining a homogeneous solution, a membrane material was prepared using solution casting. The obtained copolymer solution was cast onto a Teflon petri dish, and the solvent was evaporated in an 80°C oven until completely evaporated. The membrane was then peeled off from the petri dish, thoroughly washed with deionized water, and further dried to obtain a uniform and transparent copolymer membrane. The obtained membrane was immersed in an 85 wt% phosphoric acid aqueous solution at 80°C for 24 hours to obtain a high-temperature proton exchange membrane with a phosphoric acid doping content of 272 wt%. This high-temperature proton exchange membrane material exhibited a conductivity of 89 mS / cm at 180°C without humidification.

[0048] Example 3

[0049] At 20°C, 7.71 g of tetramethyltetrahydro-spirodi[indane]-diol (25 mmol) and 3.57 g of 1-ethyl-1H imidazol-2-carboxaldehyde (28.75 mmol) were added to 40 mL of dichloromethane at a molar ratio of tetramethyltetrahydro-spirodi[indane]-diol : 1-ethyl-1H imidazol-2-carboxaldehyde = 1 : 1.15, and stirred until homogeneous. After cooling the flask in an ice bath, 5 mL of trifluoroacetic acid was added dropwise with constant stirring. After stirring for 10 min, 10 mL of trifluoromethanesulfonic acid was added, and the reaction was stirred at room temperature for 20 min. The reaction solution was then cooled to room temperature and slowly poured into an aqueous sodium bicarbonate solution to precipitate flocculent fibers. After standing, the flocculent fibers were discharged and washed three times with deionized water. After thorough washing, the solution was dried. The copolymer was dried for 12 hours to obtain a copolymer solution. The copolymer was dissolved in DMAC at 80°C using magnetic stirring to form a 2.0 wt% copolymer solution. After obtaining a homogeneous solution, a membrane material was prepared using solution casting. The obtained copolymer solution was cast onto a Teflon petri dish, and the solvent was evaporated in an 80°C oven until completely evaporated. The membrane was then peeled off from the petri dish, thoroughly washed with deionized water, and further dried to obtain a uniform and transparent copolymer membrane material. The obtained membrane was immersed in an 85 wt% phosphoric acid aqueous solution at 30°C for 24 hours to obtain a high-temperature proton exchange membrane with a phosphoric acid doping content of 136 wt%. The conductivity of this high-temperature proton exchange membrane material at 180°C without humidification was 33.2 mS / cm.

[0050] Example 4

[0051] At 20°C, 7.71 g of tetramethyltetrahydro-spirodi[indane]-diol (25 mmol) and 3.95 g of 1-propyl-1H imidazol-2-carboxaldehyde (28.75 mmol) were added to 40 mL of dichloromethane at a molar ratio of tetramethyltetrahydro-spirodi[indane]-diol : 1-propyl-1H imidazol-2-carboxaldehyde = 1 : 1.15, and stirred until homogeneous. After cooling the flask in an ice bath, 5 mL of trifluoroacetic acid was added dropwise with constant stirring. After stirring for 10 min, 10 mL of trifluoromethanesulfonic acid was added, and the reaction was stirred at room temperature for 20 min. The reaction solution was then cooled to room temperature and slowly poured into an aqueous sodium bicarbonate solution to precipitate flocculent fibers. After standing, the flocculent fibers were discharged and washed three times with deionized water. After thorough washing, the solution was dried. The copolymer was dried for 12 hours to obtain a copolymer solution. The copolymer was dissolved in DMAC at 80°C using magnetic stirring to form a 2.0 wt% copolymer solution. After obtaining a homogeneous solution, a membrane material was prepared using solution casting. The obtained copolymer solution was cast onto a Teflon petri dish, and the solvent was evaporated in an 80°C oven until completely evaporated. The membrane was then peeled off from the petri dish, thoroughly washed with deionized water, and further dried to obtain a uniform and transparent copolymer membrane material. The obtained membrane was immersed in an 85 wt% phosphoric acid aqueous solution at 30°C for 24 hours to obtain a high-temperature proton exchange membrane with a phosphoric acid doping content of 142 wt%. The conductivity of this high-temperature proton exchange membrane material at 180°C without humidification was 36.3 mS / cm.

[0052] Example 5

[0053] At 20°C, 7.71 g of tetramethyltetrahydro-spirodi[indane]-diol (25 mmol) and 4.13 g of 1-butyl-1H imidazol-2-carboxaldehyde (28.75 mmol) were added to 40 mL of dichloromethane at a molar ratio of tetramethyltetrahydro-spirodi[indane]-diol : 1-butyl-1H imidazol-2-carboxaldehyde = 1 : 1.15, and stirred until homogeneous. After cooling the flask in an ice bath, 5 mL of trifluoroacetic acid was added dropwise with constant stirring. After stirring for 10 min, 10 mL of trifluoromethanesulfonic acid was added, and the reaction was stirred at room temperature for 20 min. The reaction solution was then cooled to room temperature and slowly poured into an aqueous sodium bicarbonate solution to precipitate flocculent fibers. After standing, the flocculent fibers were discharged and washed three times with deionized water. After thorough washing, the solution was dried. The copolymer was dried for 12 hours to obtain a copolymer solution. The copolymer was then dissolved in DMAC at 80°C using magnetic stirring to form a 2.0 wt% copolymer solution. After obtaining a homogeneous solution, a membrane material was prepared using solution casting. The obtained copolymer solution was cast onto a Teflon petri dish, and the solvent was evaporated in an 80°C oven until completely evaporated. The membrane was then peeled off from the petri dish, thoroughly washed with deionized water, and further dried to obtain a uniform and transparent copolymer membrane material. The obtained membrane was immersed in an 85 wt% phosphoric acid aqueous solution at 30°C for 24 hours to obtain a high-temperature proton exchange membrane with a phosphoric acid doping content of 149 wt%. The conductivity of this high-temperature proton exchange membrane material at 180°C without humidification was 37.9 mS / cm.

[0054] Comparative Example 1

[0055] At 20°C, 5.76 g of terphenyl (25 mmol) and 3.58 g of 1-methyl-1H-imidazolium-2-carboxaldehyde (32.5 mmol) were added to 40 mL of dichloromethane at a molar ratio of terphenyl:1:1.3, and stirred until homogeneous. After cooling the flask in an ice bath, 5 mL of trifluoroacetic acid was added dropwise with constant stirring. After stirring for 5 min, 20 mL of trifluoromethanesulfonic acid was added, and the reaction was stirred at room temperature for 30 min. The reaction solution was then cooled to room temperature and slowly poured into an aqueous sodium bicarbonate solution to precipitate flocculent fibers. After standing, the flocculent fibers were discharged and washed three times with deionized water. After thorough washing, the mixture was dried for 12 hours to obtain the copolymer. At 80°C, the copolymer was dissolved in DMAC using magnetic stirring to form... A 2.0 wt% copolymer solution was used. After obtaining a homogeneous solution, the membrane material was prepared by solution casting, i.e., the obtained copolymer solution was cast onto a Teflon petri dish, and then the solvent was evaporated in an 80°C oven until completely evaporated. The membrane was then peeled off from the petri dish, thoroughly washed with deionized water, and further dried to obtain a homogeneous and transparent copolymer membrane material. The obtained membrane was immersed in a 75 wt% phosphoric acid aqueous solution at 30°C for 24 hours to obtain a high-temperature proton exchange membrane with a phosphoric acid doping content of 171 wt%. The conductivity of this high-temperature proton exchange membrane material at 160°C without humidification was 25.9 mS / cm.

[0056] The exchange membranes prepared in Example 2 were subjected to structural characterization and performance testing. The mass swelling, area swelling, and volume swelling rates of the membranes prepared in each example are shown below. Figure 1 As shown, the mechanical properties of each membrane are as follows: Figure 2 As shown, the conductivity of each membrane at different temperatures is as follows: Figure 3 As shown; the 1H NMR spectra of the copolymers prepared in Examples 1 and 2 are as follows. Figure 4 As shown.

[0057] The membrane sample (3 cm × 1 cm) was immersed in an 85 wt% phosphoric acid solution (PA) at 30 °C until equilibrium was reached. The acid doping content (ADC%) was calculated using formula (1) based on the mass ratio of the doped membrane (m1) to the undoped membrane (m0). The dimensional changes in length, width, and thickness before and after doping were measured, and the area expansion (A%) and volume expansion (V%) were calculated using formulas (2) and (3).

[0058] (1)

[0059] (2)

[0060] (3)

[0061] Where: m1 is the mass of the film sample after phosphoric acid doping; m0 is the mass of the film sample; L1 is the length of the film sample after phosphoric acid doping; L0 is the length of the film sample; W1 is the width of the film sample after phosphoric acid doping; W0 is the width of the film sample; D1 is the thickness of the film sample after phosphoric acid doping; D0 is the thickness of the film sample.

[0062] Subsequent 1H NMR analysis was performed, using tetramethylsilane (TMS) as an internal standard and deuterated trichloromethane (CDCl3) as a solvent. The mechanical properties of the dumbbell-shaped membrane were determined using a mechanical strength tester at room temperature (RT) in air with a constant elongation of 5 mm / min. The anhydrous proton conductivity of the membrane was measured using a four-probe conductivity cell at approximately 5 kHz and an oven. Before each measurement, the phosphoric acid-doped membrane sample was preheated at 100 °C for at least 1 h to avoid the influence of moisture content and to obtain accurate and repeatable conductivity values.

[0063] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A twisted imidazole-based high-temperature proton exchange membrane, characterized in that, The general formula for the twisted structure of the imidazole-based high-temperature proton exchange membrane is as follows: or or or ; In the general formula, n is a positive integer.

2. A method for preparing a twisted imidazole-based high-temperature proton exchange membrane as described in claim 1, characterized in that, Includes the following steps: Step 1: Mix one of 1-methyl-1H imidazol-2-carboxaldehyde, 1-ethyl-1H imidazol-2-carboxaldehyde, 1-propyl-1H imidazol-2-carboxaldehyde, 1-butyl-1H imidazol-2-carboxaldehyde, tetramethyltetrahydro-spirodi[indane]-diol with a polar organic solvent to obtain a reactant solution; Step 2: Add trifluoroacetic acid and trifluoromethanesulfonic acid to the reactant solution to carry out the reaction. After precipitation, wash and dry the precipitate to obtain the copolymer. Step 3: Prepare a copolymer membrane material from the copolymer polymer; Step 4: Dope the copolymer membrane material with phosphoric acid to obtain a twisted structure imidazole-based high-temperature proton exchange membrane.

3. The method for preparing the imidazole-based high-temperature proton exchange membrane with a twisted structure according to claim 2, characterized in that, In step 1, the polar organic solvent is dichloromethane.

4. The method for preparing the twisted imidazole-based high-temperature proton exchange membrane according to claim 2, characterized in that, In step 1, the molar ratio of one of 1-methyl-1H imidazol-2-carboxaldehyde, 1-ethyl-1H imidazol-2-carboxaldehyde, 1-propyl-1H imidazol-2-carboxaldehyde, and 1-butyl-1H imidazol-2-carboxaldehyde to tetramethyltetrahydro-spirodi[indane]-diol is 1.15:

1.

5. The method for preparing the imidazole-based high-temperature proton exchange membrane with a twisted structure according to claim 2, characterized in that, In step 2, the ratio of trifluoroacetic acid to tetramethyltetrahydro-spirodi[indane]-diol added in step 1 is (0.6-0.7) mL:1g, and the ratio of trifluoromethanesulfonic acid to tetramethyltetrahydro-spirodi[indane]-diol added in step 1 is (1.2-1.4) mL:1g.

6. The method for preparing the imidazole-based high-temperature proton exchange membrane with a twisted structure according to claim 2, characterized in that, In step 2, the reaction temperature is 10℃-30℃ and the reaction time is 30min.

7. The method for preparing the twisted imidazole-based high-temperature proton exchange membrane according to claim 2, characterized in that, Step 3 specifically involves: dissolving the copolymer in N,N-dimethylacetamide to prepare a copolymer solution; pouring the copolymer solution into a petri dish, evaporating the solvent until dry, peeling the membrane off the petri dish, washing, and drying to obtain a uniform and transparent copolymer membrane material.

8. The method for preparing the imidazole-based high-temperature proton exchange membrane with a twisted structure according to claim 7, characterized in that, In step 3, the copolymer is dissolved in N,N-dimethylacetamide at 75℃~85℃, and the concentration of the copolymer solution is 2wt%-4wt%.

9. The method for preparing the imidazole-based high-temperature proton exchange membrane with a twisted structure according to claim 7, characterized in that, The solvent evaporation temperature is 80℃.

10. The method for preparing the twisted imidazole-based high-temperature proton exchange membrane according to claim 2, characterized in that, In step 4, the concentration of the phosphoric acid aqueous solution used for phosphoric acid doping is 85wt%, and the phosphoric acid doping soaking time is 24h~72h; the phosphoric acid doping amount of the distorted imidazole high-temperature proton exchange membrane is 122wt%~272wt%.

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