Polyvinylpyrrolidone-polyethersulfone high-temperature proton exchange membrane and preparation method thereof

Abstract

The invention discloses a polyvinylpyrrolidone-polyethersulfone high-temperature proton exchange membrane and a preparation method thereof, the polyvinylpyrrolidone-polyethersulfone high-temperature proton exchange membrane comprises a membrane main material and a dopant, the membrane main material comprises polyvinylpyrrolidone and polyethersulfone, and the dopant is a mixture of polyvinylpyrrolidone and polyethersulfone. The doping agent is amino silane coupling agent surface modified tin dioxide, and the addition mass ratio of the doping agent is 1%-4% based on the membrane main material. The inorganic doped polyvinylpyrrolidone-polyethersulfone membrane is obtained through film forming by a tape casting method, the preparation process is simple, the raw material cost is low, and the prepared inorganic doped membrane has the advantages of good mechanical strength, strong proton conduction capability and the like after being doped with phosphoric acid, and has wide application prospects in high-temperature proton exchange membrane fuel cells.

Description

Technical Field

[0001] The invention relates to the technical field of fuel cells, and in particular to a polyvinyl pyrrolidone-polyether sulfone high-temperature proton exchange membrane and a preparation method thereof. Background Art

[0002] As the core component of high temperature proton exchange membrane fuel cell (HT-PEMFC), high temperature proton exchange membrane (HT-PEM) is responsible for conducting protons and blocking reactants and electrons. Polyvinylpyrrolidone (PVP), as a nitrogen-containing heterocyclic alkaline polymer, achieves proton transmission by adsorbing phosphoric acid (PA). However, the hydrophilicity and brittleness of PVP itself limit its application under high temperature conditions, so it needs to be compounded with other materials to improve its mechanical properties and application temperature range.

[0003] Polyethersulfone (PES) is an engineering plastic with excellent thermal and chemical stability. When blended with PVP, it can significantly improve the high-temperature application capability and mechanical properties of the composite membrane. The rigid structure of PES helps to improve the mechanical stability of the proton exchange membrane (PEM), while the pyrrole ring and carbonyl group in PVP can adsorb PA, enhancing the adsorption capacity of PEM for PA, thereby improving proton conductivity.

[0004] Although PVP-PES blend membranes have made progress in improving high-temperature proton conductivity, there are limitations on the PA doping level. Although too high a PA doping level can improve proton conductivity, too much PA will be adsorbed around the polymer main chain, increasing the distance between polymer chains, resulting in a decrease in the interaction force between the main chains, which will lead to plasticization of the polymer main chain, causing PEM to swell and reduce the mechanical properties of PEM.

[0005] In order to solve this problem, organic-inorganic blending technology has attracted the attention of researchers as a method to improve the dimensional stability and mechanical properties of PEM. 2, graphite carbon nitride (Carbon Nitride, CN), phosphotungstic acid, etc., can further improve the performance of PEM. However, on the one hand, the inorganic doping filler has poor dispersion in PEM, is easy to aggregate, and is easy to destroy the structure of the composite membrane, resulting in reduced mechanical strength; on the other hand, the introduction of inorganic dopants in PEM is likely to lead to a decrease in the number of free PA around the polymer main chain, affecting the composite membrane's adsorption capacity for PA, thereby resulting in a decrease in proton conductivity. Summary of the invention

[0006] In order to overcome the deficiencies of the prior art, the present invention aims to develop an inorganically doped high temperature proton exchange membrane which has high proton conductivity while maintaining mechanical properties.

[0007] In order to achieve the above-mentioned purpose, the present invention provides a polyvinyl pyrrolidone-polyether sulfone high-temperature proton exchange membrane, comprising a membrane main material and a dopant, wherein the membrane main material comprises polyvinyl pyrrolidone and polyether sulfone, the dopant is aminosilane coupling agent surface-modified tin dioxide, and the added mass ratio of the dopant is 1% to 4%, calculated on the basis of the membrane main material.

[0008] Furthermore, the mass ratio of polyvinyl pyrrolidone to polyether sulfone is (5-7):(3-5).

[0009] The present invention also provides a method for preparing the above-mentioned polyvinyl pyrrolidone-polyether sulfone high temperature proton exchange membrane, comprising:

[0010] Step S1, dissolving polyvinyl pyrrolidone and polyether sulfone in a first polar aprotic solvent to obtain a homogeneous solution;

[0011] Step S2, dispersing the aminosilane coupling agent surface-modified tin dioxide in a second polar aprotic solvent to obtain a doping solution;

[0012] Step S3, after the homogeneous solution and the doping solution are uniformly mixed, a film is formed by a casting method, and the first polar aprotic solvent and the second polar aprotic solvent are removed by heating and evaporation to form a blended film;

[0013] Step S4, soaking the blended membrane in phosphoric acid to obtain a polyvinyl pyrrolidone-polyether sulfone membrane high-temperature proton exchange membrane.

[0014] Furthermore, the first polar aprotic solvent and the second polar aprotic solvent are the same or different.

[0015] Furthermore, the first polar aprotic solvent and the second polar aprotic solvent are independently selected from any one or more of N,N-dimethylacetamide, N,N-dimethylformamide, N-methylpyrrolidone or dimethyl sulfoxide.

[0016] Furthermore, in step S3, the heating evaporation temperature is 60° C. to 80° C. and maintained for 5 h to 15 h.

[0017] Furthermore, in the step S4, the concentration of the phosphoric acid is 70wt% to 98wt%, and the soaking time is 15h to 30h.

[0018] The present invention also provides a membrane electrode, comprising the above-mentioned polyvinyl pyrrolidone-polyether sulfone high-temperature proton exchange membrane.

[0019] The present invention also provides a fuel cell comprising the membrane electrode.

[0020] Compared with the prior art, the present invention has at least the following beneficial effects:

[0021] (1) The present invention introduces aminosilane coupling agent into the surface of polyvinyl pyrrolidone-polyether sulfone (PVP-PES) membrane through doping modification to modify tin dioxide (NH 2 -SnO 2 ), NH 2 -SnO 2 It can form a dense organic-inorganic composite structure with PVP-PES membrane to improve the mechanical strength of the membrane; moreover, NH 2 -SnO 2 The introduction of NH4+ reduced the amount of free PA, thereby reducing the plasticization of the polymer chain and the swelling rate of the membrane after PA adsorption, thus avoiding the reduction of the mechanical strength of the membrane caused by PA. 2 -SnO 2 The amino groups in the PA can form a hydrogen bond network with the amide groups of the polyvinyl pyrrolidone. The hydrogen bond, as a strong intermolecular force, helps to limit the movement of the polymer chain and enhance the interaction between the main chains, thereby further reducing the swelling rate and improving the mechanical strength. In addition, the hydrogen bond network provides a continuous and efficient transmission channel for proton transport, compensating for the reduced proton transfer efficiency caused by the reduced PA adsorption. Therefore, without relying on excessively high proportions of PA doping, the present invention can improve the proton conductivity of the membrane, thereby making NH 2 -SnO 2 Doped PVP-PES high temperature proton exchange membrane combines mechanical strength and high proton conductivity.

[0022] (2) The polyvinyl pyrrolidone-polyether sulfone membrane of the present invention is suitable for mass production. Since the doping process of the inorganic dopant is simple and the film is formed by the casting method, it is suitable for large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1The phosphoric acid absorption and anti-swelling performance diagram of the aminosilane coupling agent surface modified tin dioxide doped polyvinyl pyrrolidone-polyether sulfone high temperature proton exchange membrane material prepared in Examples 1 to 4 of the present invention and the polyvinyl pyrrolidone-polyether sulfone membrane of Comparative Example 1 after being immersed in 85wt% phosphoric acid at room temperature for 24 hours.

[0024] Figure 2 This is a graph of the proton conductivity performance of the aminosilane coupling agent surface modified tin dioxide doped polyvinyl pyrrolidone-polyether sulfone high temperature proton exchange membrane material prepared in Examples 1 to 4 of the present invention and the polyvinyl pyrrolidone-polyether sulfone membrane of Comparative Example 1 under non-humidification conditions in the range of 80°C to 180°C.

[0025] Figure 3 This is a fuel cell performance diagram of the aminosilane coupling agent surface modified tin dioxide doped polyvinyl pyrrolidone-polyether sulfone high temperature proton exchange membrane material prepared in Examples 1 to 4 of the present invention and the polyvinyl pyrrolidone-polyether sulfone membrane of Comparative Example 1 under non-humidified hydrogen and oxygen conditions at 160°C. DETAILED DESCRIPTION

[0026] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] In the description of the present invention, the terms “first”, “second” and “third” are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0028] As described in the background technology, existing high-temperature proton exchange membranes have problems such as weak mechanical properties and low electrical conductivity. There is an urgent need for an inorganic doping material that has both good phosphoric acid (PA) dispersibility and excellent proton conductivity to obtain a high-performance polyvinyl pyrrolidone-polyether sulfone membrane with high proton conductivity and excellent fuel cell performance.

[0029] The inventors found through research that aminosilane coupling agent surface modified tin dioxide (NH 2 -SnO 2 ) can effectively improve the comprehensive performance of the composite membrane:

[0030] First, NH 2 -SnO 2It is an inorganic metal oxide material that exhibits the ability to scavenge hydroxyl radicals (·OH) and peroxy radicals (HOO·) through redox cycles, thereby improving the antioxidant stability of the composite membrane. Moreover, due to its inorganic rigid structure, an organic-inorganic structure can be formed in the composite membrane, thereby improving the mechanical strength of the composite membrane.

[0031] Second, NH 2 -SnO 2 As an inorganic dopant, it competes with PA for adsorption sites on the polymer backbone, so NH 2 -SnO 2 The addition of NH4+ reduces the amount of free PA in the polymer chain, so that the composite membrane will not adsorb too much PA. When PA is doped into the polymer membrane, although PA acts as a medium for proton conduction, its excessive doping will increase the free volume between the polymer chains. This phenomenon causes the gaps between the polymer chains to increase and the binding force between the chains to decrease, thus causing the volume expansion of the membrane (plasticization phenomenon). Therefore, adding NH4+ 2 -SnO 2 An excessively high PA doping level is avoided, the swelling rate of the composite membrane after adsorbing PA is reduced, and the reduction in the mechanical strength of the membrane caused by PA is avoided.

[0032] Third, NH 2 -SnO 2 Containing amino groups, a hydrogen bond network can be constructed between amino groups and amide groups of polyvinylpyrrolidone (PVP). On the one hand, hydrogen bonds, as a strong intermolecular force, can enhance the interaction between polymer chains and further reduce the swelling rate; on the other hand, hydrogen bonds can provide another continuous and efficient transmission channel for proton transmission, compensating for the reduction in proton transfer efficiency caused by the reduction in PA adsorption. Therefore, without relying on an excessively high proportion of PA doping, the present invention can achieve the improvement of proton conductivity and the improvement of the proton conductivity of the composite membrane.

[0033] The NH 2 -SnO 2 The synthesis method is as follows: 2g SnO 2 (Shanghai Aladdin Reagent Co., Ltd.) was dispersed in 40 mL of ethanol and stirred and ultrasonicated SnO 2 The dispersion was stirred for 30 min and ultrasonicated twice to ensure that SnO 2 The particles are well dispersed in the medium. At room temperature, SnO 2 The dispersion was added with 4 mL of aminosilane coupling agent ((3-aminopropyl)trimethoxysilane (KH550), Shanghai MacLean Biotechnology Co., Ltd.) and stirred at room temperature for 12 hours. After the reaction was completed, centrifugation was performed. The product was repeatedly washed with water and ethanol. After washing, the product was dried in an oven at 80°C for 24 hours to obtain the NH2 -SnO 2 .

[0034] The present invention provides a polyvinylpyrrolidone-polyethersulfone (PVP-PES-NH 2 SnO 2 ) a high temperature proton exchange membrane, wherein the high temperature proton exchange membrane comprises a membrane main material and a dopant, wherein the membrane main material comprises polyvinyl pyrrolidone (PVP) and polyether sulfone (PES), and the dopant is NH 2 -SnO 2 , the PVP, PES and NH 2 -SnO 2 The molecular structures are shown below:

[0035]

[0036] Wherein, the mass ratio of PVP to PES is (5-7): (3-5), and the NH 2 -SnO 2 The added mass ratio is 1% to 4%, based on the main material of the membrane.

[0037] PVP-PES-NH of the present invention 2 SnO 2 The high temperature proton exchange membrane preparation method includes: using PVP and PES as raw materials, NH 2 -SnO 2 As an inorganic dopant, PVP-PES-NH 2 SnO 2 High temperature proton exchange membrane.

[0038] The specific steps of the preparation method are as follows: PVP and PES are dissolved in a first polar aprotic solvent to obtain a homogeneous solution, and then NH 2 -SnO 2 Ultrasonic dispersion in a second polar aprotic solvent to obtain a doping solution, the homogeneous solution and the doping solution are mixed and stirred, after ultrasonic homogenization, a film is formed by a casting method, and the first polar aprotic solvent and the second polar aprotic solvent are removed by heating and evaporation to obtain a blended film; the blended film is immersed in phosphoric acid to obtain PVP-PES-NH 2 SnO 2 High temperature proton exchange membrane.

[0039] In the above preparation method, the first polar aprotic solvent and the second polar aprotic solvent may be the same or different.

[0040] In the above preparation method, the first polar aprotic solvent and the second polar aprotic solvent are independently selected from one of N,N-dimethylacetamide, N,N-dimethylformamide, N-methylpyrrolidone or dimethyl sulfoxide.

[0041] In the above preparation method, the heating evaporation temperature is 60° C. to 80° C. and maintained for 5 h to 15 h, so as to completely remove the first polar aprotic solvent and the second polar aprotic solvent to facilitate film formation.

[0042] In the above preparation method, the concentration of the phosphoric acid is 70wt% to 98wt%, and the immersion time is 15h to 30h, so that the blended membrane can fully absorb the phosphoric acid.

[0043] Unless otherwise specified, the chemicals used in the present invention are all conventional commercially available chemical reagents. These chemicals can be purchased from a number of chemical reagent suppliers and do not require special preparation or synthesis.

[0044] The present invention is further described in detail below in conjunction with specific embodiments.

[0045] Example 1

[0046] This embodiment provides an aminosilane coupling agent surface modified tin dioxide doped polyvinyl pyrrolidone-polyether sulfone (PVP-PES-NH 2 SnO 2 )High temperature proton exchange membrane.

[0047] PVP-PES-NH 2 SnO 2 The preparation method of high temperature proton exchange membrane material is as follows:

[0048] Step S1, using polyvinyl pyrrolidone (PVP) and polyether sulfone (PES) as raw materials, using N-methyl pyrrolidone solution as solvent, adding the PVP and PES into the N-methyl pyrrolidone solution, the mass ratio of PVP to PES is 7:3, stirring at room temperature for 12 hours to dissolve it, and obtaining a polyvinyl pyrrolidone-polyether sulfone solution.

[0049] Step S2, surface-modified tin dioxide (NH 2 -SnO 2 ) was added to the N-methylpyrrolidone solution, stirred at room temperature and ultrasonically dispersed to obtain NH 2 -SnO 2 Disperse the suspension uniformly. Wherein, control the NH 2 -SnO 2The mass ratio of the polyvinyl pyrrolidone-polyether sulfone (PVP-PES) solution is 1:100, that is, 1 wt% of NH 2 -SnO 2 .

[0050] Step S3: NH 2 -SnO 2 The uniformly dispersed suspension is added to the PVP-PES solution, stirred and uniformly dispersed by ultrasound at room temperature to obtain a membrane solution with a total mass fraction of PVP-PES of 15 wt %.

[0051] Step S4, forming a film by a tape casting method, casting the film solution in step S3 on a glass plate, heating at 60° C. for 12 h, and volatilizing and removing N-methylpyrrolidone to obtain an inorganic doped polyvinylpyrrolidone-polyethersulfone (PVP-PES-NH 2 SnO 2 ) blend film.

[0052] Step S5, the PVP-PES-NH 2 SnO 2 The blended membrane was taken out after being immersed in 85 wt % phosphoric acid (PA) at room temperature for 24 hours, thereby obtaining the desired composite high temperature proton exchange membrane, which was recorded as PVP-PES-1%.

[0053] Example 2

[0054] The difference between this embodiment and embodiment 1 is that in step S2, NH 2 -SnO 2 The added mass ratio of PVP-PES is 2 wt %. The obtained composite high temperature proton exchange membrane is recorded as PVP-PES-2%.

[0055] Example 3

[0056] The difference between this embodiment and embodiment 1 is that in step S2, NH 2 -SnO 2 The added mass ratio of PVP-PES is 3 wt %. The obtained composite high temperature proton exchange membrane is recorded as PVP-PES-3%.

[0057] Example 4

[0058] The difference between this embodiment and embodiment 1 is that in step S2, NH 2 -SnO 2 The added mass ratio of PVP-PES is 4 wt %. The obtained composite high temperature proton exchange membrane is recorded as PVP-PES-4%.

[0059] Comparative Example 1

[0060] This comparative example provides a polyvinyl pyrrolidone-polyether sulfone (PVP-PES) high temperature proton exchange membrane, which is different from Example 1 in that NH 2 -SnO 2 The specific preparation process of PVP-PES high temperature proton exchange membrane is as follows:

[0061] PVP and PES were added to N-methylpyrrolidone solution (mass ratio: PVP:PES = 7:3) and stirred at room temperature for 12 hours to dissolve them evenly, obtaining a uniform transparent solution with a PVP-PES mass fraction of 15wt%; the uniform transparent solution was cast on a glass plate by a casting method, heated at 60°C for 12 hours, and a polyvinylpyrrolidone-polyethersulfone (PVP-PES) blended membrane was obtained after N-methylpyrrolidone was volatilized and removed. The PVP-PES blended membrane was taken out after being soaked in 85wt% phosphoric acid at room temperature for 24 hours to obtain the desired high-temperature proton exchange membrane, which was recorded as PVP-PES.

[0062] The high temperature proton exchange membranes with different doping amounts obtained in Examples 1 to 4 and Comparative Example 1 were subjected to the following off-line and on-line tests.

[0063] Referring to GB / T 20042.3-2022, the swelling rate of the obtained high-temperature proton exchange membrane was tested. The specific operating conditions were as follows: under constant temperature and humidity conditions of 23°C ± 2°C and 50% ± 5%, the initial length L of the sample was measured with a caliper. 0 and the initial width W 0 , use a thickness gauge to measure the thickness of the sample d 0 , calculate the initial volume V 0 =L 0 ×W 0 ×d 0 After the sample is immersed in a constant temperature condition of room temperature and 85% phosphoric acid concentration for 24 hours, the length L and width W of the sample are measured with a caliper, and the thickness d of the sample is measured with a thickness gauge, and the volume after immersion is calculated as V = L × W × d. v =V 0 / V.

[0064] Referring to GB / T 20042.3-2022, the proton conductivity of the obtained high temperature proton exchange membrane was tested. The specific operating conditions were: at a temperature of 80°C to 180°C and a humidity of 0%, a conductivity test device was connected to an electrochemical impedance tester.

[0065] With reference to GB / T 20042.5-2009, the obtained high temperature proton exchange membrane was made into a high temperature proton exchange membrane fuel cell, and a polarization curve test was carried out. The specific operating conditions were: the operating temperature of the single cell was 160°C, the anode was fed with pure hydrogen, the cathode was fed with normal pressure oxygen, and the ratio of cathode feed to anode feed was 1:1.

[0066] Test results such as Figures 1 to 3 shown.

[0067] See also Figure 1 , the phosphoric acid adsorption (doping) rate and swelling rate of the composite membranes of Example 1, Example 2, Example 3, Example 4 and the membrane of Comparative Example 1 of the present invention were measured. It can be seen from the figure that after phosphoric acid adsorption, the phosphoric acid adsorption rates corresponding to Example 1, Example 2, Example 3, Example 4 and Comparative Example 1 of the present invention were measured to be 409.8%, 407.02%, 395.93%, 390.24% and 416.84% respectively. The corresponding swelling rates were 224.54%, 222.75%, 215.66%, 207.29% and 231.3% respectively. Compared with the membrane in Comparative Example 1, the PA adsorption rate of the inorganic doped composite membranes in Examples 1, 2, 3 and 4 of the present invention maintained a high level, but the PA adsorption rate was slightly reduced compared with Comparative Example 1, which avoided the reduction of the binding force between chains caused by excessive doping of PA, thereby reducing the plasticization of the polymer main chain by PA and reducing the deformation and swelling of the membrane; the high-temperature proton exchange membrane prepared by the present invention has a smaller swelling rate and higher swelling resistance, which proves that the PVP-PES-NH prepared by the present invention 2 SnO 2 High temperature proton exchange membrane has good mechanical properties and dimensional stability and is not easy to break or deform.

[0068] See also Figure 2 The proton conductivity of the composite membranes of Example 1, Example 2, Example 3, Example 4 and the membrane of Comparative Example 1 was measured. It can be seen from the figure that at 100°C, the proton conductivity of Example 1, Example 2, Example 3, Example 4 and Comparative Example 1 was 0.076S·cm -1 、0.077S·cm -1 , 0.082S·cm -1 , 0.072S·cm -1 、0.070S·cm -1 At 160°C, the proton conductivity of Example 1, Example 2, Example 3, Example 4, and Comparative Example 1 of the present invention was measured to be 0.119 S·cm -1 、0.129S·cm -1 、0.134S·cm -1 、0.109S·cm -1, 0.098S·cm -1 Compared with the membrane of comparative example 1, the inorganic doped composite membranes of examples 1, 2, 3 and 4 of the present invention have higher proton conductivity and better proton conductivity, which proves that the hydrogen bond network in the present invention effectively compensates for the reduced proton transfer efficiency caused by the reduced PA adsorption, and the hydrogen bond network provides an efficient transmission channel for proton transfer.

[0069] See also Figure 3 The fuel cell performance graphs of the composite membranes of Example 1, Example 2, Example 3, and Example 4 of the present invention and the membrane of Comparative Example 1 were measured. It can be seen from the graph that at 0.1 A / cm 2 When the membrane electrode voltages corresponding to the embodiment 1, embodiment 2, embodiment 3, embodiment 4 and comparative example 1 of the present invention are measured, they are 0.765V, 0.779V, 0.783V, 0.752V and 0.708V respectively. The fuel cell power densities corresponding to the embodiment 1, embodiment 2, embodiment 3, embodiment 4 and comparative example 1 of the present invention are measured, they are 76.5mW·cm -2 、77.9mW·cm -2 、78.3mW·cm -2 、75.2mW·cm -2 、70.8mW·cm -2 . At 0.5A / cm 2 When the membrane electrode voltages corresponding to the embodiment 1, embodiment 2, embodiment 3, embodiment 4 and comparative example 1 of the present invention are measured, they are 0.627V, 0.645V, 0.658V, 0.541V and 0.501V respectively. The fuel cell power densities corresponding to the embodiment 1, embodiment 2, embodiment 3, embodiment 4 and comparative example 1 of the present invention are measured, they are 313.5mW·cm -2 、322.5mW·cm -2 、329.0mW·cm -2 、270.5mW·cm -2 、250.5mW·cm -2 At 1.0A / cm 2 When the membrane electrode voltages corresponding to the embodiment 1, embodiment 2, embodiment 3, embodiment 4 and comparative example 1 of the present invention are measured, they are 0.491V, 0.529V, 0.546V, 0.374V and 0.276V respectively. The fuel cell power densities corresponding to the embodiment 1, embodiment 2, embodiment 3, embodiment 4 and comparative example 1 of the present invention are measured, they are 491.0mW·cm -2 、529.0mW·cm -2 、546.0mW·cm -2 、374.0mW·cm -2 、276.0mW·cm -2Compared with the membrane of comparative example 1, the membrane electrode voltage of the inorganic doped composite membranes of examples 1, 2, 3 and 4 of the present invention is higher, which means that the membrane electrode polarization loss is smaller and the power density of the fuel cell is higher, thus proving that the PVP-PES-NH prepared by the present invention 2 SnO 2 High temperature proton exchange membrane due to NH 2 -SnO 2 The good antioxidant capacity makes the chemical stability and thermal stability of the present invention higher. And the high power density further proves that PVP-PES-NH 2 SnO 2 High temperature proton exchange membrane has high conductivity.

[0070] In summary, the present invention provides a polyvinyl pyrrolidone-polyether sulfone high temperature proton exchange membrane, which achieves high proton conductivity while maintaining good mechanical strength. The present invention adopts aminosilane coupling agent surface modified tin dioxide as an inorganic dopant, which not only improves the mechanical strength of the membrane and reduces the swelling rate while maintaining a certain phosphoric acid adsorption capacity, but also provides an efficient proton transmission channel through the hydrogen bond network formed between the amino group of aminosilane coupling agent surface modified tin dioxide and the amide group of polyvinyl pyrrolidone, which significantly improves the proton conductivity of the membrane, thereby improving the power density of the prepared high temperature proton exchange membrane fuel cell. In addition, the preparation process of the membrane is simple, suitable for large-scale industrial production, and has a high practical application value.

[0071] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.

Claims

1. A polyvinyl pyrrolidone-polyether sulfone high temperature proton exchange membrane, characterized in that: The invention comprises a main membrane material and a dopant, wherein the main membrane material comprises polyvinyl pyrrolidone and polyether sulfone, the dopant is aminosilane coupling agent surface-modified tin dioxide, and the added mass ratio of the dopant is 1% to 4% based on the main membrane material.

2. The polyvinyl pyrrolidone-polyether sulfone high temperature proton exchange membrane according to claim 1, characterized in that: The mass ratio of polyvinyl pyrrolidone to polyether sulfone is (5-7):(3-5).

3. A method for preparing a polyvinyl pyrrolidone-polyether sulfone high temperature proton exchange membrane according to claim 1 or 2, characterized in that: Include: Step S1, dissolving polyvinyl pyrrolidone and polyether sulfone in a first polar aprotic solvent to obtain a homogeneous solution; Step S2, dispersing the aminosilane coupling agent surface-modified tin dioxide in a second polar aprotic solvent to obtain a doping solution; Step S3, after the homogeneous solution and the doping solution are uniformly mixed, a film is formed by a casting method, and the first polar aprotic solvent and the second polar aprotic solvent are removed by heating and evaporation to form a blended film; Step S4, soaking the blended membrane in phosphoric acid to obtain a polyvinyl pyrrolidone-polyether sulfone membrane high-temperature proton exchange membrane.

4. The preparation method according to claim 3, characterized in that: The first polar aprotic solvent and the second polar aprotic solvent are the same or different.

5. The preparation method according to claim 4, characterized in that: The first polar aprotic solvent and the second polar aprotic solvent are independently selected from any one or more of N,N-dimethylacetamide, N,N-dimethylformamide, N-methylpyrrolidone or dimethyl sulfoxide.

6. The preparation method according to claim 3, characterized in that: In the step S3, the heating evaporation temperature is 60° C. to 80° C. and maintained for 5 h to 15 h.

7. The preparation method according to claim 3, characterized in that: In the step S4, the concentration of the phosphoric acid is 70 wt% to 98 wt%, and the soaking time is 15 h to 30 h.

8. A membrane electrode, characterized in that: It comprises the polyvinyl pyrrolidone-polyether sulfone high temperature proton exchange membrane as claimed in claim 1 or 2.

9. A fuel cell, characterized in that: A membrane electrode comprising the membrane electrode according to claim 8.

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