High-temperature Proton Exchange Membrane for Fuel Cells and Its Preparation Method

Abstract

The present invention discloses a high-temperature proton exchange membrane and a preparation method thereof. The high-temperature proton exchange membrane comprises a polyionic liquid and a tetramethyl polyaryletherketone, and the two undergo a crosslinking reaction to obtain the high-temperature proton exchange membrane. The present invention also discloses a high-temperature proton exchange membrane fuel cell assembled by using the high-temperature proton exchange membrane. The present invention selects low-cost raw materials and adopts a simple and easy-to-control process to prepare the high-temperature proton exchange membrane. The prepared high-temperature proton exchange membrane has a microscopic membrane structure with microphase hydrophilic / hydrophobic phase separation, good proton conductivity and mechanical strength, and excellent power density of the high-temperature proton exchange membrane fuel cell is obtained.

Description

Technical Field

[0001] The present invention belongs to the technical fields of electrolyte materials and high-temperature proton exchange membrane fuel cells, and particularly relates to a high-temperature proton exchange membrane for fuel cells and a preparation method thereof. Background Art

[0002] A proton exchange membrane fuel cell (PEMFC) is a clean energy technology that directly converts chemical energy into electrical energy. It also has the characteristics of being noiseless, having a fast response, and being able to output continuously, and thus has broad application prospects in production and life. As a key material in fuel cells, the proton exchange membrane functions to conduct protons and prevent direct contact between fuels and oxidants. Therefore, the performance of the proton exchange membrane will greatly affect the performance of fuel cells. Currently, perfluorosulfonic acid-based proton exchange membranes (such as Nafion membranes) are the most representative and widely used proton exchange membranes. The chemical structure of perfluorosulfonic acid endows it with good chemical stability and proton conductivity. However, this type of perfluorosulfonic acid-based proton exchange membrane is prone to dehydration at high temperatures (≥80 °C), and the proton conductivity rapidly decreases, putting the fuel cell in an unstable state and being unfavorable for the cycle service life. Therefore, fuel cells need to be equipped with a precise water / thermal management system. In addition, fuel cells based on such perfluorosulfonic acid-based proton exchange membranes require high-purity hydrogen as fuel, and trace impurities (such as CO) in the fuel will poison the catalyst, having a negative impact on the performance of fuel cells. Nafion membranes mainly rely on imports and are expensive. These shortcomings and deficiencies limit the popularization and application of proton exchange membrane fuel cell technology.

[0003] In order to overcome the high cost of perfluorosulfonic acid proton exchange membranes such as Nafion membranes, non-perfluorinated proton exchange membranes and non-fluorinated proton exchange membranes with slightly lower price costs have been developed. However, it is very difficult to achieve a balance between proton conductivity and the mechanical strength of the membrane.

[0004] Increasing the operating temperature of fuel cells is one of the effective measures to solve the complexity of the battery water / thermal management system and catalyst poisoning. The operating temperature of high-temperature fuel cell systems is 100 - 200 °C, and its operating characteristics can, to a certain extent, make up for the above problems. First of all, increasing the temperature can effectively promote the catalytic reaction kinetic processes at the cathode and anode, improve the utilization efficiency of Pt catalysts, and at the same time inhibit the adsorption of CO on Pt-based catalysts, preventing catalyst poisoning. Then, the fuel gas does not need to be humidified in the battery system, the temperature difference between the system and the environment increases, and the cooling efficiency improves, thus simplifying the water / thermal management. Therefore, it is necessary to research and develop high-temperature proton exchange membranes.

[0005] There are mainly two methods for preparing high-temperature proton membrane fuels in the prior art.

[0006] One method is to add hydrophilic inorganic solid oxides into the membrane to enhance its water retention performance. For example, Nafion membranes are doped with nano-silica. The solid medium can increase the proton conductivity by increasing the distribution density of silanol groups on its surface. However, it is difficult for the doped silica to be evenly distributed in the membrane, and local damage to the membrane is likely to occur during operation in high-temperature and low-humidity environments.

[0007] Another method is to use high-boiling-point proton solvents instead of water as the proton conduction medium. For example, imidazole and phosphoric acid are used as proton conduction media. Currently, most high-temperature proton exchange membranes use phosphoric acid (PA) with good thermal and chemical stability as the proton transport medium. However, phosphoric acid-doped membranes still face problems such as low proton conductivity, which limits the development of high-temperature proton exchange membrane fuel cells. To improve the proton conductivity, the method of increasing the phosphoric acid adsorption content is usually adopted. However, as the adsorbed phosphoric acid content increases, the three-dimensional swelling of the membrane becomes more obvious, and the mechanical strength of the membrane will decrease due to the plasticizer effect of phosphoric acid molecules, which is not conducive to the long-term stability of high-temperature proton exchange membrane fuel cells.

[0008] In the prior art, there is a polybenzimidazole polyionic liquid cross-linked composite high-temperature proton exchange membrane. The polyionic liquid can adsorb phosphoric acid, which can improve the phosphoric acid adsorption performance. The polybenzimidazole membrane has good chemical and thermal stability and certain mechanical strength, which can improve the chemical and mechanical properties of high-temperature proton membranes. However, the above raw material components still have the problem of high cost, and the monomers for synthesizing polybenzimidazole have high carcinogenicity, increasing the synthesis and use risks, which limits its development to a certain extent. Moreover, polybenzimidazole and polyionic liquid are cross-linked with a cross-linking agent, the process is complex, and it cannot effectively construct ion transport channels, restricting its application in fuel cell assembly. Therefore, it is of great significance for the development of high-temperature proton exchange membrane fuel cells to prepare membrane materials with low cost, high temperature resistance, high proton conductivity, and high mechanical strength through a simple and easy-to-control process. Summary of the Invention

[0009] The object of the present invention is to provide a high-temperature proton exchange membrane for fuel cells and its preparation method. The present invention selects low-cost raw materials and uses a simple and easy-to-control process to prepare a high-temperature proton exchange membrane. The prepared high-temperature proton exchange membrane has a microphase-separated membrane structure with hydrophilic / hydrophobic microphases, good proton conductivity and mechanical strength, and excellent power density of high-temperature proton exchange membrane fuel cells is obtained.

[0010] On the one hand, the present invention provides a high-temperature proton exchange membrane for fuel cells. The membrane material includes, by polymer type: poly(pentenyl 1,4-diazabicyclo[2.2.2]octane-1-ium bromide) and bromomethyl polyaryl ether ketone.

[0011] On the other hand, the present invention also provides a method for preparing a high-temperature proton exchange membrane for fuel cells, which includes the following steps: blending and casting a film from poly(pentenyl 1,4-diazabicyclo[2.2.2]octane-1-ium bromide) and bromomethylated polyarylether ketone in a solution state, and further soaking the obtained film in phosphoric acid to prepare the high-temperature proton exchange membrane.

[0012] Among them, a crosslinking reaction occurs during the film-forming process, and its structural formula is as shown in Formula (I).

[0013]

[0014] According to an embodiment of the present invention, poly(pentenyl 1,4-diazabicyclo[2.2.2]octane-1-ium bromide) can be dissolved in dimethyl sulfoxide to form a polyionic liquid solution, and bromomethylated polyarylether ketone can be dissolved in N-methylpyrrolidone to obtain a bromomethylated polyarylether ketone solution.

[0015] Preferably, the solid content of the polyionic liquid is 0.3 g / mL.

[0016] Preferably, the solid content of the bromomethylated polyarylether ketone solution is 0.05 g / mL.

[0017] Preferably, the volume ratio of the polyionic liquid to the bromomethylated polyarylether ketone solution is (0.2 - 1):1. If the proportion of the polyionic liquid is too small, the proton conductivity of the proton exchange membrane will be too low to meet the requirements; if the proportion of the polyionic liquid is too large, the proton exchange membrane will be easily dissolved during use, reducing its service life.

[0018] Preferably, the high-temperature proton exchange membrane needs to be soaked in phosphoric acid at room temperature for 24 hours before use.

[0019] Preferably, the blending and casting of the film is carried out by the casting method.

[0020] Preferably, the specific process of film formation by the casting method is: casting the casting solution obtained by blending onto a glass plate, drying at 70 °C for 12 hours, and then raising the temperature to 120 °C and drying for 5 hours.

[0021] On the other hand, the present invention also provides a method for preparing poly(pentenyl 1,4-diazabicyclo[2.2.2]octane-1-ium bromide) and bromomethylated polyarylether ketone.

[0022] Synthesize a crosslinkable polyionic liquid:

[0023] Prepare an ionic liquid monomer: pentenyl 1,4-diazabicyclo[2.2.2]octane-1-ium bromide by reacting 1,4-diazabicyclo[2.2.2]octane with 5-bromo-1-pentene. Hereinafter, it is referred to as ionic liquid. Then, prepare a crosslinkable polyionic liquid: poly(pentenyl 1,4-diazabicyclo[2.2.2]octane-1-ium bromide) by free radical polymerization of the prepared ionic liquid monomer. Its structural formula is shown in Formula (II). Hereinafter, it is referred to as polyionic liquid.

[0024]

[0025] Preferably, the amount of 1,4-diazabicyclo[2.2.2]octane used is 16.9 g, and the amount of 5-bromo-1-pentene used is 23.8 mL. Dissolve these two monomers in 250 mL of acetone and react at 50 °C for 3 hours to obtain the ionic liquid monomer.

[0026] Preferably, take 6 g of the ionic liquid and dissolve it in 20 mL of dimethyl sulfoxide solution. Add 3% azobisisobutyronitrile as an initiator and carry out a free radical polymerization reaction at 80 °C for 48 hours. Then precipitate and wash the obtained reaction product with ethyl acetate, and vacuum dry to obtain a viscous dark yellow polyionic liquid.

[0027] Synthesize bromomethylated polyaryletherketone:

[0028] Prepare a tetramethyl polyaryletherketone polymer by condensation polymerization of 3,3',5,5'-tetramethyl-4,4'-biphenol and 4,4'-difluorobenzophenone. Then further brominate the prepared tetramethyl polyaryletherketone using N-bromosuccinimide as the brominating reagent and benzoyl peroxide as the initiator to prepare bromomethylated polyaryletherketone. Its structural formula is shown in Formula (III).

[0029]

[0030] Preferably, the amount of 3,3',5,5'-tetramethyl-4,4'-biphenol used is 14.54 g, and the amount of 4,4'-difluorobenzophenone used is 13.09 g. Dissolve the two monomers in 63 mL of sulfolane. Add 20 mL of toluene to the solution, heat the mixed solution to 130 °C and keep it for 3 hours, then heat it to 170 °C and keep it for 5 hours. Then obtain the tetramethyl polyaryletherketone polymer through steps such as curing in clear water, cutting into pieces, washing, and drying.

[0031] Preferably, 6.3 g of tetramethyl polyaryletherketone was weighed and dissolved in 250 mL of chloroform. 5.34 g of N-bromosuccinimide was used as the bromination reagent, and 1 g of benzoyl peroxide was used as the initiator. The reaction was carried out at 60 °C for 9 hours. Then, through steps such as curing in acetone, cutting, washing, and drying, the bromomethyl polyaryletherketone polymer was obtained.

[0032] On the other hand, the present invention also provides a fuel cell including the above high-temperature proton exchange membrane for fuel cells.

[0033] Advantages of the present invention

[0034] 1. First, the present invention provides a high-temperature proton exchange membrane for fuel cells. The high-temperature proton exchange membrane comprises, by composition: polyaryletherketone and polyionic liquid. Currently, the representative low-temperature proton exchange membranes are mainly commercial perfluorosulfonic acid-based proton exchange membranes (such as Nafion membranes), and the representative high-temperature proton exchange membranes are mainly polybenzimidazole high-temperature proton exchange membranes. The high-temperature proton exchange membrane prepared in the present invention uses easily available raw materials, and the cost is lower than both of the above two proton exchange membranes.

[0035] 2. Polyionic liquid has hydrophilic properties, and polyaryletherketone has hydrophobic properties. In the present invention, through crosslinking, two polymers with large differences in hydrophilic / hydrophobic properties are closely combined, avoiding phase separation. Moreover, by adopting a special crosslinking method, a microscopic hydrophilic / hydrophobic phase separation structure is formed at the nanoscale. The microscopic hydrophilic / hydrophobic phase separation structure helps to establish an ion transport channel, thereby achieving the effect of improving proton conductivity. In the present invention, the polyionic liquid plays a role in adsorbing phosphoric acid, and at the same time, the hydrophilic phase formed by the polyionic liquid constructs the ion transport channel; polyaryletherketone serves as the supporting framework structure of the membrane. On the one hand, it ensures that the membrane has good mechanical properties, and on the other hand, this special crosslinked structure of polyaryletherketone and polyionic liquid can inhibit the excessive swelling caused by phosphoric acid adsorption and maintain the dimensional stability of the membrane.

[0036] 3. The polyionic liquid prepared based on 1,4-diazabicyclo[2.2.2]octane in the present invention is more prone to the occurrence of crosslinking reactions during the membrane preparation process because 1,4-diazabicyclo[2.2.2]octane contains two nitrogen sites.

[0037] 4. The proton conductivity of the high-temperature proton exchange membrane is usually positively correlated with the phosphoric acid content. However, too high a phosphoric acid adsorption content is likely to cause excessive swelling of the membrane and a reduction in mechanical strength. The phosphoric acid adsorption content of the high-temperature proton exchange membrane prepared in the present invention is 170 - 240%, which is a medium phosphoric acid adsorption content. However, under the positive effect of the microscopic hydrophilic / hydrophobic phase separation structure, it finally exhibits a relatively high proton conductivity of 85 mS / cm to 139 mS / cm. Moreover, the peak power density of the fuel cell assembled with the high-temperature proton exchange membrane reaches 490 mW / cm2 , ranking in the upper-middle level in the current research of high-temperature proton exchange membrane fuel cells (J. Mater. Chem. A, 2022, 10, 10916).

[0038] In view of the fact that the raw material cost of the high-temperature proton exchange membrane in the present invention is relatively low, the preparation process is simple and easy to control, a microscopically hydrophilic / hydrophobic phase separation structure can be formed at the nanoscale, and the power density of the obtained fuel cell is not lower than that of the proton exchange membranes in the prior art, such as Nafion membrane and polybenzimidazole high-temperature proton exchange membrane. Therefore, the high-temperature proton exchange membrane prepared by the present invention has the potential for application in the field of fuel cells. Description of the Drawings

[0039] Figure 1 (a) is the nuclear magnetic resonance spectrum of tetramethyl polyaryletherketone (TMPAEK) and bromomethyl polyaryletherketone (BrTMPAEK); (b) is the nuclear magnetic resonance spectrum of ionic liquid (IL) and polyionic liquid (PIL).

[0040] Figure 2 (a) is the membrane prepared by directly compounding tetramethyl polyaryletherketone (TMPAEK) and polyionic liquid (PIL), showing phase separation; (b) is the membrane prepared by the cross-linking reaction of bromomethyl polyaryletherketone (BrTMPAEK) and polyionic liquid (PIL), showing good film-forming property.

[0041] Figure 3 is the differential scanning calorimetry curve (DSC) of the prepared TMPAEK-PIL high-temperature proton exchange membrane.

[0042] Figure 4 is the transmission electron microscopy image (TEM) of the prepared TMPAEK-PIL high-temperature proton exchange membrane.

[0043] Figure 5 is the polarization curve and power density curve of the high-temperature proton exchange membrane fuel cell assembled with the prepared TMPAEK-PIL high-temperature proton exchange membrane. Detailed Embodiments

[0044] In order to further understand the present invention, the preferred implementation modes of the present invention will be described in detail below in combination with embodiments. However, it should be understood that these descriptions are only for further explaining the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0045] Preparation of Raw Materials:

[0046] (1) Synthesis of polyionic liquid: Weigh 16.9 g of 1,4-diazabicyclo[2.2.2]octane into a 500 mL single-mouth round-bottom flask, add 250 mL of acetone and stir. After the solute is fully dissolved, add 23.8 mL of 5-bromo-1-pentene to the solution and stir at 50°C for 3 hours. A white crystalline precipitate is generated in the flask. The obtained white precipitate is washed with acetone and filtered to obtain a solid product which is dried under vacuum at 45°C to obtain a dry ionic liquid product. Take 6 g of ionic liquid and dissolve it in 20 mL of dimethyl sulfoxide solution, add 3% azobisisobutyronitrile as an initiator, and perform a free radical polymerization reaction at 80°C for 48 hours. After the reaction is completed, the solution turns dark yellow. The dark yellow solution is poured into ethyl acetate to produce a precipitate. The supernatant is discarded and the obtained precipitate is vacuum dried to obtain a viscous dark yellow polyionic liquid.

[0047] (2) Synthesis of bromomethyl polyaryletherketone: Weigh 14.54g of 3,3',5,5'-tetramethyl-4,4'-biphenyldiphenol and 13.09g of 4,4'-difluorobenzophenone, and dissolve the two monomers in 63mL of cyclopentane sulfone. The container is a three-necked round-bottom flask equipped with mechanical stirring, nitrogen protection, reflux device and water separation device. Add 20mL of toluene to the solution, first heat the mixed solution to 130℃ for condensation reflux and water separation for 3 hours, and then heat it to 170℃ for 5 hours to complete the condensation polymerization. The product is poured into deionized water to form white strips. Cut the white strips into pieces and boil them with deionized water for 10 times. Finally, the tetramethyl polyaryletherketone polymer is obtained and dried for use. Weigh 6.3g of tetramethyl polyaryletherketone and dissolve it in 250mL of chloroform. Use 5.34g of bromosuccinimide as a brominating agent and 1g of benzoyl peroxide as an initiator. The reaction device is a three-necked round-bottom flask equipped with a mechanical stirrer, nitrogen protection, and a condensation reflux device. The temperature is raised to 60°C to keep the chloroform solution boiling for 9 hours. During the process, chloroform should be replenished in time as the volume of the chloroform solution decreases. Finally, the orange solution is poured into acetone, the solid product is cut into pieces and washed with acetone 3 times, and the synthesized bromomethyl polyaryletherketone is dried for use.

[0048] Example 1

[0049] Preparation of high-temperature proton exchange membrane: Polyionic liquid and bromomethyl polyaryletherketone were dissolved in dimethyl sulfoxide and N-methylpyrrolidone respectively to prepare a polyionic liquid solution with a solid content of 0.3 g / mL and a bromomethyl polyaryletherketone solution with a solid content of 0.05 g / mL. 0.66 mL of polyionic liquid solution and 3 mL of bromomethyl polyaryletherketone solution were mixed thoroughly to prepare a casting solution, which was cast onto a horizontal glass plate, first dried at 70°C for 12 hours to form a membrane, then heated to 120°C and dried for 5 hours to complete the cross-linking reaction, and the resulting polymer was named TMPAEK-PIL1.

[0050] The proton conductivity of the high-temperature proton exchange membrane of this example was tested, and the proton conductivity was 85 mS / cm under anhydrous conditions at 150 °C.

[0051] A high-temperature proton exchange membrane fuel cell uses the high-temperature proton exchange membrane prepared in Example 1.

[0052] Example 2

[0053] Preparation of the high-temperature proton exchange membrane: The poly(ionic liquid) and bromomethylated poly(aryl ether ketone) were separately dissolved in dimethyl sulfoxide and N-methylpyrrolidone to prepare a poly(ionic liquid) solution with a solid content of 0.3 g / mL and a bromomethylated poly(aryl ether ketone) solution with a solid content of 0.05 g / mL. Take 1 mL of the poly(ionic liquid) solution and 3 mL of the bromomethylated poly(aryl ether ketone) solution and mix them thoroughly to prepare a casting solution. Cast the casting solution onto a horizontal glass plate, first dry it at 70 °C for 12 hours to form a film, and then raise the temperature to 120 °C and dry it for 5 hours to complete the cross-linking reaction. The resulting polymer was named TMPAEK-PIL2.

[0054] The proton conductivity of the high-temperature proton exchange membrane of this example was tested, and the proton conductivity was 105 mS / cm under anhydrous conditions at 150 °C.

[0055] A high-temperature proton exchange membrane fuel cell uses the high-temperature proton exchange membrane prepared in Example 2.

[0056] Example 3

[0057] Preparation of the high-temperature proton exchange membrane: The poly(ionic liquid) and bromomethylated poly(aryl ether ketone) were separately dissolved in dimethyl sulfoxide and N-methylpyrrolidone to prepare a poly(ionic liquid) solution with a solid content of 0.3 g / mL and a bromomethylated poly(aryl ether ketone) solution with a solid content of 0.05 g / mL. Take 1.33 mL of the poly(ionic liquid) solution and 3 mL of the bromomethylated poly(aryl ether ketone) solution and mix them thoroughly to prepare a casting solution. Cast the casting solution onto a horizontal glass plate, first dry it at 70 °C for 12 hours to form a film, and then raise the temperature to 120 °C and dry it for 5 hours to complete the cross-linking reaction. The resulting polymer was named TMPAEK-PIL3.

[0058] The proton conductivity of the high-temperature proton exchange membrane of this example was tested, and the proton conductivity was 137 mS / cm under anhydrous conditions at 150 °C.

[0059] A high-temperature proton exchange membrane fuel cell uses the high-temperature proton exchange membrane prepared in Example 3.

[0060] Example 4

[0061] Preparation of high-temperature proton exchange membrane: Poly(ionic liquid) and bromomethylated poly(aryl ether ketone) were separately dissolved in dimethyl sulfoxide and N-methylpyrrolidone to prepare a poly(ionic liquid) solution with a solid content of 0.3 g / mL and a bromomethylated poly(aryl ether ketone) solution with a solid content of 0.05 g / mL. 1.66 mL of the poly(ionic liquid) solution and 3 mL of the bromomethylated poly(aryl ether ketone) solution were taken and thoroughly mixed to prepare a casting solution. The casting solution was cast onto a horizontal glass plate. First, it was dried at 70 °C for 12 hours to form a film, and then the temperature was raised to 120 °C and dried for 5 hours to complete the cross-linking reaction. The resulting polymer was named TMPAEK-PIL4.

[0062] The proton conductivity of the high-temperature proton exchange membrane of this example was measured, and the proton conductivity was 139 mS / cm under anhydrous conditions at 150 °C.

[0063] A high-temperature proton exchange membrane fuel cell uses the high-temperature proton exchange membrane prepared in Example 4.

[0064] Figure 1 (a) is the 1 H NMR spectrum of tetramethyl poly(aryl ether ketone) and bromomethylated poly(aryl ether ketone), Figure 1 (b) is the 1 H NMR spectrum of the ionic liquid monomer and poly(ionic liquid). The target polymer was successfully prepared by the synthesis method of the present invention.

[0065] Figure 2 (a) is a membrane prepared by directly compounding tetramethyl poly(aryl ether ketone) (TMPAEK) and poly(ionic liquid) (PIL). Due to the large hydrophilicity difference between poly(aryl ether ketone) and poly(ionic liquid), phase separation occurred and a uniform membrane could not be formed; (b) is a membrane prepared by the cross-linking reaction of bromomethylated poly(aryl ether ketone) (BrTMPAEK) and poly(ionic liquid) (PIL). Due to the cross-linking reaction between the two polymers, their compatibility was enhanced, showing good film-forming properties.

[0066] Figure 3 This is the result obtained from the DSC test of the TMPAEK-PIL high-temperature membrane prepared by the present invention. Compared with the pure TMPAEK membrane, due to the establishment of the cross-linked structure in the TMPAEK-PIL high-temperature membrane prepared by the present invention, the glass transition temperature (T g ) of the membrane increased from 203 °C to ~241 °C, enhancing the thermal stability of the high-temperature proton exchange membrane.

[0067] Figure 4 This is the characterization of the microscopic morphology of the TMPAEK-PIL high-temperature membrane prepared by the present invention through TEM test. It can be seen that black and white phase regions appear in the microscopic morphology of the membrane at the nanoscale. The black represents the hydrophilic phase where ionic clusters aggregate, and the white represents the hydrophobic phase where poly(aryl ether ketone) aggregates. This indicates that the prepared high-temperature membrane forms a microscopic hydrophilic / hydrophobic phase separation structure.

[0068] Figure 5 The results are obtained from the high-temperature proton exchange membrane fuel cells assembled with the prepared high-temperature proton exchange membranes. It can be found that through the structural design of the high-temperature proton exchange membrane of the present invention, the proton conductivity of the high-temperature proton exchange membrane is improved, and thus the peak power density of the prepared high-temperature proton exchange membrane fuel cell can reach up to 490 mW / cm under the condition of 140 °C. 2 , demonstrating the excellent performance and application potential of such high-temperature proton exchange membranes.

[0069] The description of the above embodiments is only used to help understand the method and its core idea of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. High-temperature proton exchange membrane for fuel cells, characterized in that, The high-temperature proton exchange membrane comprises: poly(pentenyl 1,4-diazabicyclo[2.2.2]octane-1-ium bromide) and bromomethylated polyaryletherketone, and the preparation method of the high-temperature proton exchange membrane comprises blending and casting the poly(pentenyl 1,4-diazabicyclo[2.2.2]octane-1-ium bromide) and the bromomethylated polyaryletherketone in a solution state.

2. The high-temperature proton exchange membrane for fuel cells according to claim 1, wherein The high-temperature proton exchange membrane adsorbs phosphoric acid.

3. A preparation method of a high-temperature proton exchange membrane for a fuel cell, characterized in that, The preparation method comprises: blending and casting the poly(pentenyl 1,4-diazabicyclo[2.2.2]octane-1-ium bromide) and the bromomethylated polyaryletherketone in a solution state, and further soaking the obtained membrane in phosphoric acid to prepare the high-temperature proton exchange membrane.

4. The preparation method of the high-temperature proton exchange membrane for fuel cells according to claim 3, the preparation method comprising: Dissolve poly(pentenyl 1,4-diazabicyclo[2.2.2]octane-1-ium bromide) in dimethyl sulfoxide to form a polyionic liquid solution, and dissolve bromomethylated polyaryletherketone in N-methylpyrrolidone to obtain a bromomethylated polyaryletherketone solution.

5. The preparation method of the high-temperature proton exchange membrane for fuel cells according to claim 4, wherein the solid content of the polyionic liquid solution is 0.3 g / mL, the solid content of the bromomethylated polyaryletherketone is 0.05 g / mL, and the volume ratio of the polyionic liquid to the bromomethylated polyaryletherketone solution is (0.2-1):

1.

6. The preparation method of the high-temperature proton exchange membrane for fuel cells according to claim 3, wherein the high-temperature proton exchange membrane is soaked in phosphoric acid at room temperature for 24 hours.

7. The preparation method of the high-temperature proton exchange membrane for fuel cells according to claim 3, wherein the blending and casting is carried out by a casting method to form a film.

8. The specific process of the casting method for film formation according to claim 7 for the preparation method of the high-temperature proton exchange membrane for fuel cells is: casting the casting solution obtained by blending onto a glass plate, drying at 70°C for 12 hours, and then raising the temperature to 120°C and drying for 5 hours.

9. Application of the high-temperature proton exchange membrane for fuel cells according to any one of claims 1 or 2 or the high-temperature proton exchange membrane for fuel cells prepared by the preparation method according to any one of claims 3-8 in the field of fuel cells.

10. A fuel cell, characterized in that: Comprising the high-temperature proton exchange membrane for fuel cells according to any one of claims 1 or 2 or the high-temperature proton exchange membrane for fuel cells prepared by the preparation method according to any one of claims 3-8.

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