Composite high-temperature proton exchange membrane for fuel cells and preparation method and application thereof
By loading UiO series MOFs and heteropoly acids into a high-temperature proton exchange membrane, a uniform proton conduction network was constructed, which solved the problems of phosphoric acid loss and insufficient mechanical strength, thereby improving mechanical performance and proton transport, and enhancing the overall performance of the fuel cell.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- DALIAN INSTITUTE OF CHEMICAL PHYSICS CHINESE ACADEMY OF SCIENCES
- Filing Date
- 2023-03-22
- Publication Date
- 2026-05-19
AI Technical Summary
Existing high-temperature proton exchange membrane fuel cells suffer from problems such as high phosphoric acid loss rate, low proton conductivity, and insufficient mechanical strength, which affect battery performance and lifespan.
A composite high-temperature proton exchange membrane was used. By loading UiO series MOFs and heteropoly acids into polybenzimidazole, the particle size and distribution of nanoparticles were controlled by a solvothermal method to construct a uniform proton conduction network, thereby enhancing mechanical strength and proton conductivity.
This improved the mechanical strength and proton conductivity of the membrane, reduced the phosphoric acid loss rate, and enhanced the overall performance and stability of the battery.
Smart Images
Figure CN116435561B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of proton exchange membrane fuel cell technology, specifically relating to a composite high-temperature proton exchange membrane for fuel cells, its preparation method, and its application. Background Technology
[0002] A proton exchange membrane fuel cell (PEMFC) is an energy conversion device that directly converts chemical energy into electrical energy. As long as an oxidant and reductant are continuously supplied, it can continuously output electrical energy. High-temperature PEMFCs have advantages such as high energy efficiency, good CO tolerance, and a relatively simple hydrothermal management system, making them one of the current hot research topics. When applying polybenzimidazole to high-temperature PEMFCs, it is necessary to dope it with as much phosphoric acid as possible to ensure high proton conductivity. However, high phosphoric acid doping can lead to a rapid decrease in membrane mechanical strength, increasing the loss rate of phosphoric acid during battery operation and affecting the overall performance of the battery. Furthermore, the doped phosphoric acid is easily lost, thus affecting its service life. Phosphoric acid doping also leads to a decrease in the mechanical strength and dimensional stability of the membrane.
[0003] To address the aforementioned issues, patent CN110690485A discloses a method for doping a phosphotungstic acid-type ionic liquid into a membrane, which improves phosphoric acid absorption and proton conductivity. However, the preparation method is complex, and the phosphotungstic acid-type ionic liquid is easily lost with the generated water. Patent CN115411324A discloses a method for preparing a highly conductive metal-organic framework-supported phosphotungstic acid-chitosan composite proton exchange membrane, which can improve proton conductivity under low humidification conditions. However, the conductivity of the chitosan-based membrane is limited, and the large particle size of the doped particles can damage the membrane structure. In summary, there is still a lack in the art of developing a high-temperature proton exchange membrane that combines low phosphoric acid loss, high proton conductivity, high mechanical strength, and high thermal stability. Summary of the Invention
[0004] To address the shortcomings of existing technologies, this invention provides a high-temperature proton exchange membrane composite membrane for fuel cells that combines good proton conductivity and mechanical strength, and also provides a method for its preparation. This composite membrane exhibits good mechanical properties, excellent conductivity, and demonstrates good performance when applied to fuel cells.
[0005] To achieve the above objectives, the present invention adopts the following technical solution:
[0006] The present invention provides a composite high-temperature proton exchange membrane, the raw materials of which include polybenzimidazole (PBI), composite A@B and phosphoric acid, wherein A is a heteropolyacid with proton conduction function, B is a UiO series MOF, the mass fraction of composite A@B is 1 to 40%, and the mass ratio of A to B in composite A@B is 1:2 to 1:40.
[0007] Based on the above technical solution, further, the composite A@B is A loaded on B, and the particle size of nanoparticle B is 1-100 nm.
[0008] Based on the above technical solution, the polybenzimidazole is further classified as: mPBI (poly(2,2'-(m-phenyl)-5,5'-bibenzimidazole), ABPBI (poly(2,5-benzimidazole)), OPBI (poly(2,2'-(p-diphenyl ether)-5,5'-bibenzimidazole), PBI with sulfonic acid side chains, PBI with phosphonic acid side chains, and hyperbranched PBI, or one or a combination thereof; A is one or two of phosphotungstic acid (PTA) and phosphomolybdic acid (PMA); B is one or two of UiO-66 and UiO-66-NH2.
[0009] Another aspect of the present invention provides a method for preparing the above-mentioned composite high-temperature proton exchange membrane, the method comprising the following steps:
[0010] (1) Dissolve ZrCl4 and organic ligands in N,N-dimethylformamide and sonicate to obtain solution S1;
[0011] (2) Add hydrochloric acid to solution S1, sonicate to obtain solution S2, then transfer to a reaction vessel for solvothermal reaction, wash and dry to obtain B;
[0012] (3) Dissolve A in a mixed solution of anhydrous ethanol and deionized water to obtain solution S3;
[0013] (4) The product B obtained in step (2) is ultrasonically dispersed in solution S3 to obtain dispersion S4, which is then transferred to a reaction vessel for solvothermal reaction. After solid-liquid separation, it is washed and dried to obtain composite A@B.
[0014] (5) Dissolve polybenzimidazole in a strongly polar aprotic solvent, stir and heat to obtain solution S5;
[0015] (6) Add the complex A@B obtained in step (4) to the solution S5 obtained in step (5), and stir ultrasonically to obtain dispersion S6;
[0016] (7) The dispersion S6 obtained in step (6) is cast onto a grooved flat glass plate, dried, and then the membrane is immersed in phosphoric acid to obtain the composite high-temperature proton exchange membrane.
[0017] Based on the above technical solution, further, in step (1), the organic ligand is terephthalic acid or aminoterephthalic acid; the molar ratio of ZrCl4 to the organic ligand is 1:1; the ultrasonic power is 50-300W, and the ultrasonic time is 5-30min.
[0018] Based on the above technical solution, further, in step (2), the pH of solution S2 is 0-1; the ultrasonic power is 50-300W, and the ultrasonic time is 30-60min; the solvothermal reaction conditions are: reaction at 120℃ for 24h; the washing uses a mixed solution of anhydrous methanol and N,N-dimethylformamide with a volume ratio of 1:1; the drying is vacuum drying at a temperature of 60-80℃ for 12-24h.
[0019] Based on the above technical solution, further, in step (3), the mass fraction of A in solution S3 is 0.005-0.1%; the volume ratio of anhydrous ethanol to deionized water is 1:1.
[0020] Based on the above technical solution, further, in step (4), the mass fraction of B in solution S4 is 0.1-0.2%; the ultrasonic power is 50-300W, and the ultrasonic time is 0.5-6h; the solvothermal reaction conditions are: 100℃ for 12h; the washing uses a mixed solution of anhydrous ethanol and deionized water with a volume ratio of 1:1; the drying is vacuum drying at a temperature of 60-80℃ for 12-24h.
[0021] Based on the above technical solution, further, in step (5), the strongly polar aprotic solvent is independently one or more of N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone; the heating temperature is 80-100℃ and the heating time is 3-12h.
[0022] Based on the above technical solution, further, in step (6), the mass concentration of complex A@B in dispersion S6 is 2.5-100 mg / 15 mL; the mass fraction of PBI in solution S5 is 0.8-2 wt.%; the ultrasonic power is 50-300 W; and the ultrasonic time is 0.5-6 h.
[0023] Based on the above technical solution, further, in steps (5) and (6), the stirring is magnetic stirring, the stirring power is 50-100W, and the stirring time is 1-12h.
[0024] Based on the above technical solution, further, in step (7), the mass concentration of the phosphate used for impregnation is 50-85%, the impregnation temperature is 50-150℃, and the impregnation time is 12-36h; the drying temperature is 80-120℃, and the drying time is 6-24h.
[0025] In another aspect, the present invention provides a fuel cell membrane electrode, comprising the above-mentioned composite high-temperature proton exchange membrane.
[0026] The present invention also provides a fuel cell including the membrane electrode described above.
[0027] The beneficial effects of this invention are as follows:
[0028] (1) This invention utilizes a solvothermal method to control the particle size of MOF materials and simultaneously uses solvothermal activity to improve reactivity, thereby obtaining a uniform and suitable heteropolyacid@MOF composite material for doping. The heteropolyacid is uniformly dispersed without damaging the MOF structure, and the confinement effect ensures that the composite does not separate during doping. By controlling the ratio of the two components in the composite, the PTA content is moderate and evenly distributed in the UiO-66 pores. Furthermore, by controlling the mass fraction of the composite, acid absorption sites can be increased and proton conductivity improved while maintaining tensile strength.
[0029] (2) In the composite membrane of the present invention, MOF nanoparticles of a certain size can increase the amount of phosphoric acid adsorbed and reduce the phosphoric acid loss rate through acid-base anchoring and physical adsorption, thereby constructing a proton conduction network within the membrane and improving proton conductivity. The heteropolyacids loaded in the MOF nanoparticles can further significantly improve the proton conductivity of the composite membrane, solving the problem of decreased membrane mechanical properties caused by heteropolyacid aggregation when directly doped with heteropolyacids. Through the synergistic effect of MOF and heteropolyacids, the proton conductivity, mechanical strength, and stability are simultaneously improved. Attached Figure Description
[0030] Figure 1 SEM images of PTA@UiO-66 prepared in Example 1 and UiO-66 prepared in Comparative Example 1 are shown. a is PTA@UiO-66 and b is UiO-66.
[0031] Figure 2 The XRD patterns are of PTA@UiO-66 prepared in Example 1 and UiO-66 prepared in Comparative Example 1.
[0032] Figure 3 The TG curves are of PTA@UiO-66 prepared in Example 1 and UiO-66 prepared in Comparative Example 1.
[0033] Figure 4 The tensile strength test diagrams are of the composite high-temperature proton exchange membranes prepared in Example 1 and Comparative Example 1 of the present invention.
[0034] Figure 5 The image shows a SEM image of UiO-66 prepared in Comparative Example 5. Detailed Implementation
[0035] The present invention will be further described below with reference to specific embodiments, but this does not limit the present invention in any way.
[0036] Example 1
[0037] A composite high-temperature proton exchange membrane was prepared using polybenzimidazole and PTA@UiO-66 as raw materials, following the steps below:
[0038] Step 1: Weigh 0.233g ZrCl4 and 0.166g terephthalic acid and dissolve them in 44mL DMF. After sonicating for 10min, add 4mL hydrochloric acid and sonicate for 30min. Transfer the solution to a reaction vessel and react at 120℃ for 24h under solvothermal conditions. Centrifuge, wash with DMF and methanol, and dry at 60℃ for 12h to obtain UiO-66.
[0039] Step 2: Weigh 0.01g PTA and dissolve it in a mixed solution of 30mL anhydrous ethanol and 30mL deionized water. Weigh 0.1g UiO-66 and add it to the solution. After sonication for 30min, transfer the solution to a reaction vessel and react at 100℃ for 12h using a solvothermal method. Centrifuge, wash with anhydrous ethanol and deionized water, and dry at 60℃ for 12h to obtain PTA@UiO-66.
[0040] Step 3: Weigh 0.3g OPBI and add 20g DMAc, heat and stir at 80℃ for 3h to obtain OPBI solution. Weigh 0.06g PTA@UiO-66 into OPBI solution, sonicate for 60min, and stir for 12h to obtain casting solution.
[0041] Step 4: Pour the casting solution into a grooved glass plate and dry at 80°C for 24 hours to obtain the base membrane. Finally, immerse the base membrane in phosphoric acid with a concentration of 85% at 80°C for 24 hours to obtain a composite high-temperature proton exchange membrane.
[0042] Example 2
[0043] A composite high-temperature proton exchange membrane was prepared using polybenzimidazole and PTA@UiO-66 as raw materials, following these steps:
[0044] Step 1: Weigh 0.233g ZrCl4 and 0.166g terephthalic acid and dissolve them in 44mL DMF. After sonicating for 10min, add 4mL hydrochloric acid and sonicate for 30min. Transfer the solution to a reaction vessel and react at 120℃ for 24h under solvothermal conditions. Centrifuge, wash with DMF and methanol, and dry at 60℃ for 12h to obtain UiO-66.
[0045] Step 2: Weigh 0.02g PTA and dissolve it in a mixed solution of 30mL anhydrous ethanol and 30mL deionized water. Weigh 0.1g UiO-66 and add it to the solution. After sonication for 30min, transfer the solution to a reaction vessel and react at 100℃ for 12h using a solvothermal method. Centrifuge, wash with anhydrous ethanol and deionized water, and dry at 60℃ for 12h to obtain PTA@UiO-66.
[0046] Step 3: Weigh 0.3g OPBI and add 20g DMAc. Heat and stir at 80℃ for 3h to obtain OPBI solution. Weigh 0.06g PTA@UiO-66 into OPBI solution, sonicate for 60min, and stir for 12h to obtain casting solution.
[0047] Step 4: Pour the casting solution into a grooved glass plate and dry it at 80°C for 24 hours to obtain the base membrane. Finally, immerse the base membrane in phosphoric acid with a phosphoric acid concentration of 85%, an immersion temperature of 80°C, and an immersion time of 24 hours to obtain a composite high-temperature proton exchange membrane.
[0048] Comparative Example 1
[0049] Step 1: Weigh 0.233g ZrCl4 and 0.166g terephthalic acid and dissolve them in 44mL DMF. After sonicating for 10min, add 4mL hydrochloric acid and sonicate for 30min. Transfer the solution to a reaction vessel and react at 120℃ for 24h under solvothermal conditions. Centrifuge, wash with DMF and methanol, and dry at 60℃ for 12h to obtain UiO-66.
[0050] Step 2: Weigh 0.3g OPBI and add 20g DMAc. Heat and stir at 80℃ for 3h to obtain OPBI solution. Weigh 0.06g UiO-66 into OPBI solution, sonicate for 60min, and stir for 12h to obtain casting solution.
[0051] Step 3: Pour the casting solution into a grooved glass plate and dry it at 80°C for 24 hours to obtain the base membrane. Finally, immerse the base membrane in phosphoric acid with a phosphoric acid concentration of 85%, an immersion temperature of 80°C, and an immersion time of 24 hours to obtain a composite high-temperature proton exchange membrane.
[0052] Comparative Example 2
[0053] Step 1: Weigh 0.3g OPBI and add 20g DMAc, heat and stir at 80℃ for 3h to obtain OPBI solution. Weigh 0.06g PTA into OPBI solution, sonicate for 60min, and stir for 12h to obtain casting solution;
[0054] Step 2: Pour the casting solution into a grooved glass plate and dry at 80℃ for 24 hours to obtain the base membrane. Finally, immerse the base membrane in phosphoric acid with a phosphoric acid concentration of 85%, an immersion temperature of 80℃, and an immersion time of 24 hours to obtain a composite high-temperature proton exchange membrane.
[0055] Comparative Example 3
[0056] Step 1: Weigh 0.233g ZrCl4 and 0.166g terephthalic acid and dissolve them in 44mL DMF. After sonication for 10min, add 4mL hydrochloric acid and sonicate for 30min. Transfer the solution to a reaction vessel and react at 120℃ for 24h under solvothermal conditions. Centrifuge, wash with DMF and methanol, and dry at 60℃ for 12h to obtain UiO-66.
[0057] Step 2: Weigh 0.3g OPBI and add 20g DMAc. Heat and stir at 80℃ for 3h to obtain OPBI solution. Weigh 0.03g PTA and 0.03g UiO-66 into OPBI solution, sonicate for 60min, and stir for 12h to obtain casting solution.
[0058] Step 3: Pour the casting solution into a grooved glass plate and dry it at 80°C for 24 hours to obtain the base membrane. Finally, immerse the base membrane in phosphoric acid with a phosphoric acid concentration of 85%, an immersion temperature of 80°C, and an immersion time of 24 hours to obtain a composite high-temperature proton exchange membrane.
[0059] Comparative Example 4
[0060] Step 1: Weigh 0.233g ZrCl4, 0.166g terephthalic acid and 0.04g PTA and dissolve them in 44mL DMF. After sonication for 10min, add 4mL hydrochloric acid and sonicate for 30min. Transfer the solution to a reaction vessel and react at 120℃ for 24h using a solvothermal method. Centrifuge, wash with DMF and methanol, and dry at 60℃ for 12h to obtain PTA@UiO-66.
[0061] Step 2: Weigh 0.3g OPBI and add 20g DMAc. Heat and stir at 80℃ for 3h to obtain OPBI solution. Weigh 0.06g PTA@UiO-66 into OPBI solution, sonicate for 60min, and stir for 12h to obtain casting solution.
[0062] Step 3: Pour the casting solution into a grooved glass plate and dry it at 80°C for 24 hours to obtain the base membrane. Finally, immerse the base membrane in phosphoric acid with a phosphoric acid concentration of 85%, an immersion temperature of 80°C, and an immersion time of 24 hours to obtain a composite high-temperature proton exchange membrane.
[0063] Comparative Example 5
[0064] Step 1: Weigh 0.233g ZrCl4 and 0.166g terephthalic acid and dissolve them in 44mL DMF. After sonicating for 10min, add 4mL glacial acetic acid and sonicate for 30min. Transfer the solution to a reaction vessel and react at 120℃ for 24h under solvothermal conditions. Centrifuge, wash with DMF and methanol, and dry at 60℃ for 12h to obtain UiO-66.
[0065] Step 2: Weigh 0.01g PTA and dissolve it in a mixed solution of 30mL anhydrous ethanol and 30mL deionized water. Weigh 0.1g UiO-66 and add it to the solution. After sonicating for 30min, transfer the solution to a reaction vessel and react at 100℃ for 12h using a solvothermal method. Centrifuge, wash with anhydrous ethanol and deionized water, and dry at 60℃ for 12h to obtain PTA@UiO-66.
[0066] Step 3: Weigh 0.3g OPBI and add 20g DMAc. Heat and stir at 80℃ for 3h to obtain OPBI solution. Weigh 0.06g PTA@UiO-66 into OPBI solution, sonicate for 60min, and stir for 12h to obtain casting solution.
[0067] Step 4: Pour the casting solution into a grooved glass plate and dry it at 80°C for 24 hours to obtain the base membrane. Finally, immerse the base membrane in phosphoric acid with a phosphoric acid concentration of 85%, an immersion temperature of 80°C, and an immersion time of 24 hours to obtain a composite high-temperature proton exchange membrane.
[0068] The conductivity of the composite high-temperature proton exchange membranes of the examples and comparative examples was tested, and the results are shown in Table 1.
[0069] Table 1. Conductivity of the composite high-temperature proton exchange membranes prepared in Examples 1-2 and Comparative Examples 1-5
[0070]
[0071] Depend on Figure 1 and Figure 2 It can be seen that loading PTA did not significantly alter the crystal structure and morphology of UiO-66; Figure 3 It can be seen that loading PTA can effectively improve the thermal stability of UiO-66, thereby improving the thermal stability of the composite film; from Figure 4 It can be seen that the loading of PTA improves the mechanical strength of the composite membrane. Combined with the experimental results in Table 1, since PTA has a certain acid adsorption and solidification capacity, and also has proton conduction capacity, a more effective proton transport network is constructed within the membrane by loading PTA, thus improving the proton conductivity. Comparative Examples 2 and 3 show direct PTA doping and direct PTA doping with UiO-66, respectively. Direct PTA doping causes aggregation within the membrane, hindering proton conduction, resulting in varying degrees of conductivity decrease in both composite membranes. Comparative Example 4 uses a one-pot method to prepare the composite PTA@UiO-66. In this method, the PTA in the composite is completely encapsulated by UiO-66 and cannot play a proton conduction role. Simultaneously, PTA blocks the pores of UiO-66, reducing phosphoric acid adsorption and thus lowering the conductivity of the composite membrane. Examples 1 and 5 show the preparation of UiO-66 using hydrochloric acid and glacial acetic acid. Figure 5The results show that, in comparison, the UiO-66 particles prepared using hydrochloric acid are smaller and more suitable for doping. From the conductivity test results, it is difficult to uniformly distribute the large-particle-size UiO-66 prepared using glacial acetic acid. Therefore, the conductivity of the prepared composite film is low.
[0072] For anyone skilled in the art, many possible variations and modifications can be made to the technical solutions of this invention based on the disclosed technical content, or equivalent embodiments can be modified accordingly, without departing from the scope of the technical solutions of this invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this invention without departing from the content of the technical solutions of this invention should still fall within the protection scope of the technical solutions of this invention.
Claims
1. A method for preparing a composite high-temperature proton exchange membrane, characterized in that, Its raw materials include polybenzimidazole PBI, complex A@B and phosphoric acid, wherein A is a heteropolyacid with proton conduction function, B is a UiO series MOFs, the mass fraction of complex A@B is 1 to 40%, and the mass ratio of A to B in complex A@B is 1:2 to 1:
40. The composite A@B consists of A loaded on B, and the particle size of the nanoparticles B is 1-100 nm. The method includes the following steps: (1) Dissolve ZrCl4 and organic ligands in N,N-dimethylformamide and sonicate to obtain solution S1; (2) Add hydrochloric acid to solution S1, sonicate to obtain solution S2, then transfer to a reaction vessel for solvothermal reaction, wash and dry to obtain B; (3) Dissolve A in a mixed solution of anhydrous ethanol and deionized water to obtain solution S3; (4) The product B obtained in step (2) is ultrasonically dispersed in solution S3 to obtain dispersion S4, which is then transferred to a reaction vessel for solvothermal reaction. After solid-liquid separation, it is washed and dried to obtain composite A@B. (5) Dissolve polybenzimidazole PBI in a strongly polar aprotic solvent, stir and heat to obtain solution S5; (6) Add the complex A@B obtained in step (4) to the solution S5 obtained in step (5), and stir ultrasonically to obtain dispersion S6; (7) The dispersion S6 obtained in step (6) is cast onto a grooved flat glass plate, dried, and then the membrane is immersed in phosphoric acid to obtain the composite high-temperature proton exchange membrane. A is one or both of phosphotungstic acid PTA and phosphomolybdic acid PMA; The B is one or both of UiO-66 and UiO-66-NH2.
2. The preparation method according to claim 1, characterized in that, The types of polybenzimidazole (PBI) are: mPBI poly(2,2'-(m-phenyl)-5,5'-bibenzimidazole), ABPBI poly(2,5-benzimidazole), OPBI poly(2,2'-(p-diphenyl ether)-5,5'-bibenzimidazole, PBI with sulfonic acid side chains, PBI with phosphonic acid side chains, and one or more combinations of hyperbranched PBI.
3. The preparation method according to claim 1, characterized in that, In step (1), the organic ligand is terephthalic acid or aminoterephthalic acid; the molar ratio of ZrCl4 to the organic ligand is 1:1; the ultrasonic power is 50-300W and the ultrasonic time is 5-30min. In step (2), the pH of solution S2 is 0-1; the ultrasonic power is 50-300W and the ultrasonic time is 30-60min; the solvothermal reaction conditions are: 120℃ for 24h; the washing uses a mixed solution of anhydrous methanol and N,N-dimethylformamide in a volume ratio of 1:1; the drying is vacuum drying at a temperature of 60-80℃ for 12-24h.
4. The preparation method according to claim 1, characterized in that, In step (3), the mass fraction of A in solution S3 is 0.005-0.1%; the volume ratio of anhydrous ethanol to deionized water is 1:
1. In step (4), the mass fraction of B in solution S4 is 0.1-0.2%; the ultrasonic power is 50-300W, and the ultrasonic time is 0.5-6h; the solvothermal reaction conditions are: 100℃ for 12h; the washing uses a mixed solution of anhydrous ethanol and deionized water with a volume ratio of 1:1; the drying is vacuum drying at a temperature of 60-80℃ for 12-24h.
5. The preparation method according to claim 1, characterized in that, In step (5), the strongly polar aprotic solvent is independently one or more of N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone; the heating temperature is 80-100℃, and the heating time is 3-12h; in step (6), the mass concentration of complex A@B in dispersion S6 is 2.5-100mg / 15mL; the mass fraction of PBI in solution S5 is 0.8-2wt.%; the ultrasonic power is 50-300W, and the ultrasonic time is 0.5-6h; In steps (5) and (6), the stirring is magnetic stirring, the stirring power is 50-100W, and the stirring time is 1-12h.
6. The preparation method according to claim 1, characterized in that, In step (7), the mass concentration of phosphoric acid used for impregnation is 50-85%, the impregnation temperature is 50-150℃, and the impregnation time is 12-36h; the drying temperature is 80-120℃, and the drying time is 6-24h.
7. A fuel cell membrane electrode assembly, characterized in that, Including the composite high-temperature proton exchange membrane prepared by the preparation method according to any one of claims 1-6.
8. A fuel cell, characterized in that, Includes the membrane electrode as described in claim 7.