A perfluorosulfonic acid polymer, its preparation method, proton exchange membrane and application

Abstract

The present invention provides a perfluorosulfonic acid polymer, a preparation method, a proton exchange membrane, and applications thereof. The perfluorosulfonic acid polymer comprises a structural unit of the general formula (I): prepared by grafting a halogenated polyoxanthracene with a side-chain substituted perfluorosulfonic acid chrysene salt. Application of the perfluorosulfonic acid polymer in the preparation of a proton exchange membrane offers advantages such as a simple preparation method, mild conditions, ease of operation, and low production cost, enabling large-scale industrial production.

Description

Technical Field

[0001] The present invention relates to the technical field of electrolyte membranes, and in particular to a perfluorosulfonic acid polymer, a preparation method thereof, a proton exchange membrane and applications thereof. Background Art

[0002] Proton exchange membranes (PEMs) are efficient functional polymer separation membrane materials that play a very important role in fuel cells, water electrolysis to produce hydrogen, metal-air batteries, flow batteries, carbon dioxide reduction, supercapacitors, acid separation, and lithium extraction from salt lakes. In addition to the key ion conductivity, the high chemical stability of PEMs has been a goal that researchers in the field of membrane materials have always pursued. It directly determines whether it can be used in devices and the long-term service life of the devices. In the past two decades, polymer materials such as polyaryletherketone (sulfone), polyphenylene ether, polyolefin, polyphenylene, etc. have been widely used in the preparation of various PEMs, which greatly enriched the material system of PEMs and laid the foundation for the design and development of high-performance ion exchange membranes. However, there are still some potential problems with membrane materials prepared using these polymers. For example, the skeletons of polyaryletherketone (sulfone) and polyphenylene ether still face huge challenges in long-term stability, and the complex application environment can easily cause chemical degradation and breakage of the membrane ( Chem. Rev . 2007, 107, 3904-51; Mater. Today Commun . 2015, 3, 114-121), these objective problems also limit the large-scale industrialization of this type of ion exchange membrane materials.

[0003] Polyoxyanthene is a type of ladder-shaped or partially ladder-shaped polymer obtained by polymerization of ketone monomers and aromatic bisphenol monomers through the Friedel-Crafts hydroxyalkylation reaction mechanism under acid-catalyzed conditions. The preparation reaction is mild and does not require the use of precious metal catalysts. The resulting polymer has a high molecular weight and good solubility. At the same time, the rigid oxygen-anthene skeleton is conducive to promoting the formation of a microporous structure in the membrane, realizing the construction of efficient ion transport channels, and opening up new research directions for the development of high-performance PEMs. In 2020, Xu Tongwen et al. reported a phenylsulfonic acid-functionalized polyoxyanthene proton exchange membrane material. This membrane material has an ultra-high ionic conductivity level at a lower ion exchange capacity, but the disadvantage is that it still lags behind the commercial perfluorosulfonic acid Nafion membrane ( Angew. Chem. Int. Ed. 2020, 59, 9564-9573). This is primarily due to the poor chemical stability of non-fluorophenylsulfonic acid, which is susceptible to chemical degradation in the presence of free radicals, leading to main chain breakage. Therefore, developing a simple and effective synthetic strategy to construct chemically stable perfluorosulfonic acid groups within the polyoxanthene backbone is key to improving the chemical stability of this type of proton exchange membrane. Summary of the Invention

[0004] In view of this, in order to solve the above problems, the present invention provides a perfluorosulfonic acid polymer and its preparation method, proton exchange membrane and application. The perfluorosulfonic acid polymer material has ultra-high viscosity, and the perfluorosulfonic acid proton exchange membrane prepared using it has the characteristics of thin thickness and high stability, which expands the application field of proton exchange membranes.

[0005] In order to achieve the above object, the present invention provides a perfluorosulfonic acid polymer comprising a structural unit of the general formula shown in formula (I):

[0006] ;

[0007] Wherein, m is any integer greater than or equal to 0, and n is any integer greater than or equal to 1;

[0008] A is selected from any one of the following structural formulas 1 to 18:

[0009]

[0010] wherein R1 and R2 in Structural Formula 6 and Structural Formula 17 are respectively hydrogen, methyl, ethyl, trifluoromethyl, phenyl, o-tolyl, hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, nonyl, decyl, cyclopentyl, cyclohexyl, fluorophenyl or bromophenyl;

[0011] B is selected from any one of the following structural formulas 1' to 15':

[0012] , in Structural Formula 2', Structural Formula 8' and Structural Formula 9', X is any integer greater than or equal to 0;

[0013] M is selected from hydrogen, lithium, sodium or potassium ions.

[0014] As another object of the present invention, a method for preparing the above-mentioned perfluorosulfonic acid polymer is also provided, which is prepared by grafting a halogenated polyoxyanthene with an iodinated perfluorosulfonic acid lithium salt.

[0015] Specifically, the method includes the following steps:

[0016] Step 1. Change the structural formula to The monomer compound, the halogenated trifluoroacetophenone monomer and the trifluoromethyl ketone monomer are reacted with a catalyst in a first organic solvent to obtain a halogenated polyxanthene polymer;

[0017] Step 2. Mixing the halogenated polyxanthene polymer with copper powder and iodinated perfluorosulfonic acid lithium salt (ICF2CF2OCF2CF2SO3Li) in a second organic solvent to react to obtain a perfluorosulfonic acid polymer represented by Formula I;

[0018] Among them, the structural formula In the example, A is the same as above.

[0019] The structural formula of the trifluoromethyl ketone monomer is , B is the same as above.

[0020] The structural formula of the halogenated trifluoroacetophenone monomer is , C is selected from at least one of a chlorine atom, a bromine atom or an iodine atom.

[0021] Preferably, the molar ratio of the aromatic bisphenol monomer to the ketone monomer is 0.5-1.5:1; the molar ratio of the halogenated trifluoroacetophenone monomer to the trifluoromethyl ketone monomer is 1:1-z, where z is a positive number less than or equal to 1.

[0022] Preferably, the catalyst is selected from at least one of methanesulfonic acid, trifluoroacetic acid and / or trifluoromethanesulfonic acid.

[0023] Preferably, the first organic solvent is selected from chloroform and / or dichloromethane.

[0024] Preferably, the second organic solvent is selected from one or a combination of dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, tetrahydrofuran, chloroform, dichloromethane, toluene, ethylbenzene, xylene and ethyl acetate.

[0025] As one of the objectives of the present invention, a perfluorosulfonic acid proton exchange membrane is also provided, which is prepared from the perfluorosulfonic acid polymer provided by the above technical solution.

[0026] As one of the objects of the present invention, a method for preparing the above-mentioned perfluorosulfonic acid proton exchange membrane is also provided, comprising the following steps:

[0027] S1. dissolving a perfluorosulfonic acid polyelectrolyte in a third organic solvent to obtain a polymer solution;

[0028] S2. Casting or casting the polymer solution on a substrate, and obtaining the perfluorosulfonic acid proton exchange membrane after drying.

[0029] Preferably, the third organic solvent is one or a combination of dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, tetrahydrofuran, chloroform, dichloromethane, toluene, ethylbenzene, xylene and ethyl acetate.

[0030] Preferably, the substrate is any one of a glass plate, a copper sheet, an iron sheet, a ceramic plate, a polytetrafluoroethylene plate, a polyethylene terephthalate-based film, a polyamide-based film, a polytetrafluoroethylene-based film, a polyethylene-based film, a polypropylene-based film, a carbon fiber-based film or a glass fiber-based film.

[0031] The perfluorosulfonic acid proton exchange membrane prepared by the above technical solution is used in fuel cells, water electrolysis to produce hydrogen, metal-air batteries, flow batteries, carbon dioxide reduction, supercapacitors, nickel-hydrogen batteries, zinc-manganese batteries, acid separation, lithium extraction from salt lakes, electrodialysis, water treatment, and membrane humidification.

[0032] The beneficial technical effects obtained by the present invention are:

[0033] 1. The perfluorosulfonic acid polymer used in the preparation of proton exchange membranes prepared by the technical solution of the present invention has the characteristics of simple preparation method, mild conditions, easy operation, low preparation cost, etc., and can be produced on a large scale industrially.

[0034] 2. The perfluorosulfonic acid polyelectrolyte of the present invention can be formed into a film using commonly used industrial methods such as a coating method. The prepared perfluorosulfonic acid proton exchange membrane has the advantages of large scale, thin thickness, high mechanical strength, good stability and excellent ion conductivity. It can be used in fuel cells, water electrolysis hydrogen production, metal-air batteries, liquid flow batteries, carbon dioxide reduction, supercapacitors, electrodialysis, water treatment, membrane humidification, nickel-hydrogen batteries, zinc-manganese batteries, acid separation, salt lake lithium extraction and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is the hydrogen nuclear magnetic resonance spectrum of the perfluorosulfonic acid polymer P1b prepared in Example 1 of the present invention.

[0036] Figure 2 This is the hydrogen nuclear magnetic resonance spectrum of the perfluorosulfonic acid polymer P2b prepared in Example 2 of the present invention.

[0037] Figure 3 This is a cell polarization curve diagram when the perfluorosulfonic acid proton exchange membrane P1b-H prepared in Example 1 of the present invention is applied to a hydrogen / air proton exchange membrane fuel cell. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously,

[0039] The described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0040] The present invention provides a perfluorosulfonic acid polymer comprising a structural unit of the general formula (I):

[0041] ;

[0042] Wherein, m is any integer greater than or equal to 0, and n is any integer greater than or equal to 1;

[0043] A is selected from any one of the following structural formulas 1 to 18:

[0044]

[0045] wherein R1 and R2 in Structural Formula 6 and Structural Formula 17 are respectively hydrogen, methyl, ethyl, trifluoromethyl, phenyl, o-tolyl, hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, nonyl, decyl, cyclopentyl, cyclohexyl, fluorophenyl or bromophenyl;

[0046] B is selected from any one of the following structural formulas 1' to 15':

[0047] In structural formula 2', structural formula 8' and structural formula 9', X is any integer greater than or equal to 0; M is selected from hydrogen, lithium, sodium or potassium ion.

[0048] The perfluorosulfonic acid polymer is prepared by grafting halogenated polyoxyanthene with iodinated perfluorosulfonic acid lithium salt.

[0049] The technical solution of the present invention is further described in detail below through specific embodiments.

[0050] Example 1

[0051] This embodiment provides a perfluorosulfonic acid proton exchange membrane, and the specific preparation steps include:

[0052] 1. Resorcinol (0.55 g, 5 mmol) and 4'-bromo-2,2,2-trifluoroacetophenone (1.52 g, 6 mmol) were placed in a round-bottom flask and dissolved in 2.8 mL of dichloromethane dried over molecular sieves. Trifluoromethanesulfonic acid (1.3 mL, 20.0 mmol) was then added to the flask. After the addition of the ingredients, the mixture was stirred at room temperature for 14 h. After the reaction, a viscous, pale yellow solution was obtained. The mixture was then poured into 500 mL of anhydrous methanol to precipitate the polymer. The polymer was dissolved in dichloromethane and then poured into anhydrous methanol to precipitate. This process was repeated three times and filtered. The precipitated polymer was extracted with anhydrous methanol for 12 h and dried in a vacuum oven at 80°C for 12 h to obtain 1.5 g of halogenated polyxanthene polymer P1a in a yield of 91%.

[0053] 2. Halogenated polyxanthene polymer P1a (0.98 g, 3 mmol), copper powder (1.0 g, 15 mmol), and ICF2CF2OCF2CF2SO3Li (1.3 g, 3 mmol) were placed in a pressure bottle and dissolved in 15 mL of N-methylpyrrolidone. The system was then reacted at 100°C for 12 h. After the reaction, a green solution formed on the upper layer. The copper powder was removed by filtration through diatomaceous earth, and the filtrate was directly immersed in dilute hydrochloric acid to collect the precipitated solid powder. The polymer powder was dissolved in dimethyl sulfoxide and precipitated in deionized water. This process was repeated twice and filtered. The resulting polymer was dried in a vacuum oven at 80°C for 12 h to obtain 1.2 g of perfluorosulfonic acid polymer P1b in a 90% yield.

[0054] 3. 100 mg of perfluorosulfonic acid polymer P1b was dissolved in 50 mL of NMP or DMAc to obtain a polymer solution. This solution was then coated on a glass plate and dried in an oven at 100°C for 20 hours to prepare a polyelectrolyte membrane. Finally, the membrane was immersed in a 1 M H2SO4 solution to obtain the final perfluorosulfonic acid proton exchange membrane P1b-H. The membrane had a thickness of 20 μm, a tensile strength of 25 MPa, and a Young's modulus of 300 MPa.

[0055] The structure of the perfluorosulfonic acid polyelectrolyte P1b obtained in Example 1 was analyzed by hydrogen nuclear magnetic resonance spectroscopy, and its hydrogen nuclear magnetic resonance spectrum was as follows: Figure 1 shown.

[0056] Example 2

[0057] This embodiment provides a perfluorosulfonic acid proton exchange membrane, and the specific preparation steps include:

[0058] 1. Place biphenyldiphenol (0.93 g, 5 mmol) and 4'-bromo-2,2,2-trifluoroacetophenone (1.52 g, 6 mmol) in a round-bottom flask. Add 2.8 mL of dichloromethane dried over molecular sieves to dissolve the mixture. Then, add trifluoromethanesulfonic acid (2.6 mL, 40.0 mmol) to the flask. After the addition is complete, stir the mixture at room temperature for 13 h. After the reaction, a viscous purple-red solution forms. The mixture is then poured into 500 mL of anhydrous methanol to precipitate the polymer. The polymer is dissolved in dichloromethane and then poured into anhydrous methanol to precipitate. This process is repeated three times and filtered. The precipitated polymer is extracted with anhydrous methanol for 12 h and then dried in a vacuum oven at 80°C for 12 h to obtain 1.8 g of halogenated polyxanthene polymer P2a in a 95% yield.

[0059] 2. Halogenated polyxanthene polymer P2a (0.81 g, 2 mmol), copper powder (0.64 g, 10 mmol), and ICF2CF2OCF2CF2SO3Li (1.3 g, 3 mmol) were placed in a pressure bottle and dissolved in 10 mL of N-methylpyrrolidone. The system was then reacted at 100°C for 10 h. After the reaction, a green solution formed on the upper layer. The copper powder was removed by filtration through diatomaceous earth, and the filtrate was directly immersed in dilute hydrochloric acid to collect the precipitated solid powder. The polymer powder was dissolved in dimethyl sulfoxide and precipitated in deionized water. This process was repeated twice and filtered. The resulting polymer was dried in a vacuum oven at 80°C for 12 h to obtain 0.8 g of perfluorosulfonic acid polymer P2b in an 88% yield.

[0060] 3. 100 mg of perfluorosulfonic acid polymer (P2b) was dissolved in 50 mL of NMP or DMAc to obtain a polymer solution. This solution was then coated on a glass plate and dried in an oven at 100°C for 20 hours to prepare a polyelectrolyte membrane. Finally, the membrane was immersed in a 1 M H2SO4 solution to obtain the final perfluorosulfonic acid proton exchange membrane, P2b-H. The membrane had a thickness of 25 μm, a tensile strength of 45 MPa, and a Young's modulus of 900 MPa.

[0061] The structure of the perfluorosulfonic acid polyelectrolyte P2b obtained in Example 2 was analyzed by hydrogen nuclear magnetic resonance spectroscopy, and its hydrogen nuclear magnetic resonance spectrum was obtained as follows: Figure 2 shown.

[0062] Example 3

[0063] This embodiment provides a perfluorosulfonic acid proton exchange membrane, and the specific preparation steps include:

[0064] Hexafluorobisphenol A (1.7 g, 5 mmol) and 4'-bromo-2,2,2-trifluoroacetophenone (2.0 g, 8 mmol) were placed in a round-bottom flask, and 5.5 mL

[0065] The product was dissolved in dichloromethane dried over molecular sieves, and trifluoromethanesulfonic acid (2.6 mL, 40.0 mmol) was then added to the round-bottom flask. After addition, the system was stirred at room temperature for 18 hours. Upon completion of the reaction, a viscous black solution was obtained. The system was then poured into 500 mL of anhydrous methanol to precipitate the polymer. The polymer was dissolved in dichloromethane and then poured into anhydrous methanol to precipitate. This process was repeated three times, and the precipitated polymer was then filtered. The polymer was extracted with anhydrous methanol for 12 hours and dried in a vacuum drying oven at 80°C for 12 hours to obtain 2.8 g of halogenated polyxanthene polymer P3a in a 90% yield.

[0066] 2. Halogenated polyxanthene polymer P3a (1.1 g, 2 mmol), copper powder (1.28 g, 20 mmol), and ICF2CF2OCF2CF2SO3Li (1.3 g, 3 mmol) were placed in a pressure bottle and dissolved in 27 mL of N-methylpyrrolidone. The system was then reacted at 100°C for 10 h. After the reaction, a green solution formed on the upper layer. The copper powder was removed by filtration through diatomaceous earth. The filtrate was directly immersed in dilute hydrochloric acid, and the precipitated solid powder was collected. The polymer powder was dissolved in dimethyl sulfoxide and precipitated in deionized water. This process was repeated twice and filtered. The resulting polymer was dried in a vacuum oven at 80°C for 12 h to obtain 2.0 g of perfluorosulfonic acid polymer P3b, with a yield of 95%.

[0067] 3. 100 mg of perfluorosulfonic acid polymer P3b was dissolved in 50 mL of NMP or DMAc to obtain a polymer solution. This solution was then coated on a glass plate and dried in an oven at 100°C for 20 hours to prepare a polyelectrolyte membrane. Finally, the membrane was immersed in a 1 M H2SO4 solution to obtain the final perfluorosulfonic acid proton exchange membrane P3b-H. The membrane had a thickness of 17 μm, a tensile strength of 22 MPa, and a Young's modulus of 269 MPa.

[0068] Example 4

[0069] This embodiment provides a perfluorosulfonic acid proton exchange membrane, and the specific preparation steps include:

[0070] 1. Place biphenyldiphenol (0.93 g, 5 mmol), 4'-bromo-2,2,2-trifluoroacetophenone (1.52 g, 5 mmol), and trifluoroacetone (0.11 g, 1 mmol) in a round-bottom flask. Add 5 mL of dichloromethane dried over molecular sieves to dissolve the mixture. Then, add trifluoromethanesulfonic acid (5.2 mL, 80.0 mmol) to the flask. After the addition is complete, stir the mixture at room temperature for 15 h. After the reaction, a viscous, dark red solution forms. The mixture is then poured into 500 mL of anhydrous methanol to precipitate the polymer. The polymer is dissolved in dichloromethane and then poured into anhydrous methanol to precipitate. This process is repeated three times, and the resulting precipitates are filtered. The resulting polymer is extracted with anhydrous methanol for 12 h and then dried in a vacuum oven at 80°C for 12 h to obtain 2.3 g of halogenated polyxanthene polymer P4a in a 90% yield.

[0071] 2. Halogenated polyxanthene polymer P4a (0.75 g, 2 mmol), copper powder (0.64 g, 10 mmol), and ICF2CF2OCF2CF2SO3Li (1.3 g, 3 mmol) were placed in a pressure bottle and dissolved in 10 mL of N-methylpyrrolidone. The system was then reacted at 100°C for 10 h. After the reaction, a green solution formed on the upper layer. The copper powder was removed by filtration through diatomaceous earth. The filtrate was directly immersed in dilute hydrochloric acid, and the precipitated solid powder was collected. The polymer powder was dissolved in dimethyl sulfoxide and precipitated in deionized water. This process was repeated twice and filtered. The resulting polymer was dried in a vacuum oven at 80°C for 12 h to obtain 1.1 g of perfluorosulfonic acid polymer P4b, with a yield of 90%.

[0072] 3. 100 mg of perfluorosulfonic acid polymer P4b was dissolved in 50 mL of NMP or DMAc to obtain a polymer solution. This solution was then coated on a glass plate and dried in an oven at 100°C for 20 hours to prepare a polyelectrolyte membrane. Finally, the membrane was immersed in a 1 M H2SO4 solution to obtain the final perfluorosulfonic acid proton exchange membrane P4b-H. The membrane had a thickness of 27 μm, a tensile strength of 35 MPa, and a Young's modulus of 900 MPa.

[0073] Comparative Example 1

[0074] The Nafion 212 proton exchange membrane was purchased from the market.

[0075] The proton exchange membranes prepared in Examples 1-4 and Comparative Example 1 were subjected to ion exchange capacity (IEC), swelling rate, water absorption rate, ion conductivity test and oxidation stability test.

[0076] IEC is calculated by acid-base titration to calculate the hydrogen ion content in a certain mass of proton exchange membrane, thereby obtaining the IEC of the proton exchange membrane.

[0077] The water absorption rate and swelling rate were measured by immersing the membrane in water at 80 °C for 24 h and then testing the percentage difference between its mass and size and the initial state.

[0078] The ionic conductivity was measured using a Shanghai Chenhua electrochemical test system. The two-electrode AC impedance method was used to measure the resistance of the proton exchange membrane in a fully wet state at 80°C, and then the conductivity was calculated using a formula.

[0079] Oxidative stability was determined by immersing the membrane in Fenton's reagent (2 ppm Fe 2+ at 3.0 wt% H2O2), and the time for the membrane to break was recorded. The specific results are shown in Table 1.

[0080] Table 1 IEC, water absorption, swelling rate, conductivity and oxidation stability of Examples 1-4 and Comparative Example 1

[0081]

[0082] Table 1 shows that the perfluorosulfonic acid proton exchange membrane prepared in the present invention has comparable conductivity and oxidation stability as well as better dimensional stability than commercially available varieties. The perfluorosulfonic acid proton exchange membrane P1b-H obtained in Example 1 was applied to a hydrogen / air proton exchange membrane fuel cell. The Pt / C catalyst (60 wt% metal content) was ultrasonically mixed in a Nafion solution (20 wt% polymer and 80 wt% catalyst). The membrane electrode was prepared by a catalyst coating method: the catalyst ink was sprayed on both sides of the membrane sample. The metal loading was controlled at 0.6 mg cm -2 , the electrode area is 4 cm 2 The catalyst-coated membrane was sandwiched between two pieces of carbon paper to form an MEA. Single cell testing was performed using an 850E Multi Range fuel cell test station (Scribner associates, USA) at 80°C using the current method. Hydrogen and oxygen with a humidity of 100% were simultaneously passed to both sides of the membrane electrode at a flow rate of 400 sccm. By changing the current density and recording the corresponding voltage, the cell polarization curve was obtained, as shown in the figure below. Figure 3 As shown, the power of the cell is as high as 515 mW cm -2 .

[0083] As can be seen from the above examples, the present invention provides a perfluorosulfonic acid electrolyte material directly obtained through a mild grafting reaction between halogenated polyxanthene and iodinated perfluorosulfonic acid lithium salt. This method simplifies the preparation process of perfluorosulfonic acid polymer electrolytes and reduces production costs. The perfluorosulfonic acid proton exchange membrane prepared from the perfluorosulfonic acid polyelectrolyte material exhibits advantages such as high conductivity and excellent oxidative stability, and has significant practical application and industrial prospects.

[0084] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any variation, modification, replacement, integration, or parameter change to these embodiments, which is within the spirit and principles of the present invention and which achieves the same functionality through conventional substitutions, without departing from the principles and spirit of the present invention, falls within the scope of protection of the present invention.

Claims

1. A perfluorosulfonic acid polymer, characterized in that Containing a structural unit of the general formula shown in formula (I): Wherein, m is any integer greater than or equal to 0, and n is any integer greater than or equal to 1; A is selected from any one of the following structural formulas 1 to 18: wherein R1 and R2 in Structural Formula 6 and Structural Formula 17 are respectively hydrogen, methyl, ethyl, trifluoromethyl, phenyl, o-tolyl, propyl, butyl, pentyl, hexyl, heptyl, nonyl, decyl, cyclopentyl, cyclohexyl, fluorophenyl or bromophenyl; B is selected from any one of the following structural formulas 1' to 15': In Structural Formula 2', Structural Formula 8' and Structural Formula 9', X is any integer greater than or equal to 0; M is selected from hydrogen, lithium, sodium or potassium ions.

2. The method for preparing a perfluorosulfonic acid polymer according to claim 1, wherein: The perfluorosulfonic acid polymer is prepared by grafting a side chain of iodinated perfluorosulfonic acid lithium salt onto a halogenated polyxanthene.

3. The preparation method according to claim 2, characterized in that The following steps are involved: Step 1. reacting a monomer compound of the structural formula HO-A-OH, a halogenated trifluoroacetophenone monomer, and a trifluoromethyl ketone monomer with a catalyst in a first organic solvent to obtain a halogenated polyxanthene polymer; Step 2. mixing the halogenated polyxanthene polymer with copper powder and iodinated perfluorosulfonic acid lithium salt, and reacting them in a second organic solvent to obtain a perfluorosulfonic acid polymer represented by Formula I; Wherein, in the structural formula HO-A-OH, A is the same as that in claim 1; The structural formula of the trifluoromethyl ketone monomer is B is the same as claim 1; The structural formula of the halogenated trifluoroacetophenone monomer is C is selected from at least one of a chlorine atom, a bromine atom, and an iodine atom.

4. The preparation method according to claim 3, characterized in that The molar ratio of the aromatic bisphenol monomer to the ketone monomer is 0.5-1.5:1; the molar ratio of the halogenated trifluoroacetophenone monomer to the trifluoromethyl ketone monomer is 1:1-z, where z is a positive number less than or equal to 1.

5. The preparation method according to claim 3, characterized in that The catalyst is selected from at least one of methanesulfonic acid, trifluoroacetic acid and / or trifluoromethanesulfonic acid; The first organic solvent is selected from chloroform and / or dichloromethane; The second organic solvent is selected from one or a combination of dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, tetrahydrofuran, chloroform, dichloromethane, toluene, ethylbenzene, xylene and ethyl acetate.

6. Use of the perfluorosulfonic acid polymer according to claim 1 as an electrolyte material in an electrolyte membrane. 7 . A perfluorosulfonic acid proton exchange membrane comprising the perfluorosulfonic acid polymer according to claim 1 .

8. The method for preparing a perfluorosulfonic acid proton exchange membrane according to claim 7, characterized in that: The following steps are involved: S1. dissolving the perfluorosulfonic acid polymer in a third organic solvent to obtain a polymer solution; S2. Casting or casting the polymer solution on a substrate, and obtaining the perfluorosulfonic acid proton exchange membrane after drying.

9. The preparation method according to claim 8, characterized in that The third organic solvent is one or a combination of dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, tetrahydrofuran, chloroform, dichloromethane, toluene, ethylbenzene, xylene and ethyl acetate.

10. The preparation method according to claim 8, characterized in that The substrate is any one of a glass plate, a copper sheet, an iron sheet, a ceramic plate, a polytetrafluoroethylene plate, a polyethylene terephthalate-based film, a polyamide-based film, a polytetrafluoroethylene-based film, a polyethylene-based film, a polypropylene-based film, a carbon fiber-based film or a glass fiber-based film.

11. Use of the perfluorosulfonic acid proton exchange membrane according to claim 7 in fuel cells, water electrolysis for hydrogen production, metal-air batteries, flow batteries, carbon dioxide reduction, supercapacitors, nickel-hydrogen batteries, zinc-manganese batteries, acid separation, lithium extraction from salt lakes, electrodialysis, water treatment, and membrane humidification.

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