Preparation method of proton exchange membrane and membrane electrode, proton exchange membrane, membrane electrode and fuel cell

Abstract

The embodiment of the invention discloses a preparation method of a proton exchange membrane and a membrane electrode, the proton exchange membrane, the membrane electrode and a fuel cell. The preparation method of the proton exchange membrane provided by the invention comprises the following steps: adding a nanoparticle template into a perfluorosulfonic acid polymer solution, and stirring at a first preset speed until the dispersion degree of the nanoparticle template in the perfluorosulfonic acid polymer solution reaches a first preset dispersion degree to form a dispersion liquid; coating the surface of the proton exchange membrane with the dispersion liquid, and drying; and soaking the dried proton exchange membrane in an extraction solvent, heating to a first preset temperature interval, and then continuing to a first preset time length, so that the nanoparticle template is removed, and the prefabricated proton exchange membrane with the 3D morphological structure is obtained. The interface impedance between the proton exchange membrane and the catalyst layer can be reduced, and meanwhile, the specific surface area of the catalyst layer can be increased, so that the contact area between reaction gas and a catalyst is increased, the utilization rate of the catalyst is increased, and diffusion and mass transfer resistance of the reaction gas are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of proton exchange membrane fuel cells, and in particular to a method for preparing a proton exchange membrane and a membrane electrode, and the proton exchange membrane, the membrane electrode and a fuel cell. Background Art

[0002] A fuel cell is an electrochemical cell whose main principle is to convert the chemical energy in the fuel and oxidant directly into electrical energy through a redox reaction. As an important branch of the fuel cell field, the proton exchange membrane fuel cell has the general characteristics of fuel cells, as well as the advantages of fast start-up speed at room temperature, small size, no electrolyte loss, easy drainage, long life, high specific power and specific energy. It is not only suitable for the construction of distributed power stations, but also for mobile power supply. Therefore, the proton exchange membrane fuel cell has a very broad application prospect.

[0003] Membrane Electrode Assembly (MEA) is the core component of proton exchange membrane fuel cells and the place where fuel cells carry out redox reactions. It is mainly composed of proton exchange membrane (PEM), gas diffusion layer (GDL), catalyst (CL) and sealing materials. At present, one preparation method of membrane electrode is to directly coat or transfer the catalyst layer onto the proton exchange membrane to form a catalyst coated membrane (CCM), and then bond the catalyst coated membrane with the gas diffusion layer and the frame membrane to prepare a membrane electrode; another preparation method is to directly coat the catalyst slurry on the gas diffusion layer to prepare a gas diffusion electrode (GDE), and then press it with the proton exchange membrane to form a gas diffusion electrode type membrane electrode. The preparation method of membrane electrode is currently only focused on the two processes of catalyst coated membrane type and gas diffusion electrode type. Therefore, in the membrane electrode, the interface impedance that exists seriously affects the performance of the battery, such as the interface impedance between the catalyst layer and the proton exchange membrane. Moreover, both methods combine a catalyst layer formed by a catalyst slurry (generally a mixture of a Pt / C catalyst, a perfluorosulfonic acid polymer solution and an alcohol solution) with a proton exchange membrane and a gas diffusion layer. Therefore, in the catalyst layer structure, the catalyst particles are stacked together, resulting in a low porosity of the catalyst layer, a low catalyst utilization rate of the contact area with the reaction gas, which is not conducive to gas diffusion and mass transfer processes, and seriously affects the performance of the fuel cell. Summary of the invention

[0004] In order to solve the above technical problems, the present application provides a method for preparing a proton exchange membrane and a membrane electrode, as well as a proton exchange membrane, a membrane electrode and a fuel cell. The method for preparing a proton exchange membrane provided by the present application prepares a coating with a 3D morphology structure on the surface of the proton exchange membrane to obtain a proton exchange membrane with a 3D morphology structure. By regulating the morphology structure of the proton exchange membrane, the interface impedance between the proton exchange membrane and the catalyst layer can be reduced. At the same time, the specific surface area of ​​the catalyst layer is increased, so that the contact area between the reaction gas and the catalyst is increased, the utilization rate of the catalyst is improved, and the diffusion and mass transfer resistance of the reaction gas are reduced, and the performance of the fuel cell is further improved. The specific preparation method is as follows:

[0005] In a first aspect, the present application provides a method for preparing a proton exchange membrane, comprising:

[0006] Adding the nanoparticle template to the perfluorosulfonic acid polymer solution, stirring at a first preset speed until the dispersion degree of the nanoparticle template in the perfluorosulfonic acid polymer solution reaches a first preset dispersion degree, to form a dispersion liquid;

[0007] coating the dispersion on the surface of a proton exchange membrane and drying it;

[0008] The dried proton exchange membrane is immersed in an extraction solvent, heated to a first preset temperature range and then continued for a first preset time, so that the nanoparticle template is removed to obtain a prefabricated proton exchange membrane with a 3D morphology structure.

[0009] In some specific embodiments, after obtaining the prefabricated proton exchange membrane having a 3D morphology structure, the method further comprises:

[0010] Immersing the prefabricated proton exchange membrane with the 3D morphology structure in a mixed solution of sulfuric acid and hydrogen peroxide solution, heating to a second preset temperature range and then continuing for a second preset time to remove the remaining inorganic metal ions therein;

[0011] The prefabricated proton exchange membrane is taken out and dried to obtain a proton exchange membrane with a 3D morphology structure.

[0012] In some specific embodiments, the nanoparticle template comprises one or more of inorganic nanoparticles, organic nanoparticles, and organometallic nanoparticles;

[0013] The inorganic nanoparticles include one or more of silicon dioxide, titanium dioxide, sodium carbonate, calcium carbonate, magnesium carbonate, sodium bicarbonate, calcium oxide, magnesium oxide, aluminum oxide, sodium chloride, magnesium chloride, potassium chloride and magnesium sulfate;

[0014] The organic nanoparticles include polystyrene nanospheres;

[0015] The organometallic nanoparticles include one or more of ZIF-8 and ZIF-67.

[0016] In some specific embodiments, the particle size d of the nanoparticle template is 10 nm ≤ d ≤ 1000 nm;

[0017] The dispersion is coated on the surface of the proton exchange membrane, and the coating thickness t after drying is 50nm≤t≤5000nm;

[0018] The content of the nanoparticle template in the dispersed solution is between 0.1% and 50%.

[0019] In some specific embodiments, the first preset speed is between 1000 rpm and 10000 rpm;

[0020] The first preset time is between 8 hours and 12 hours, and the first preset temperature range is between 80° C. and 120° C.;

[0021] The second preset time period is between 6 hours and 12 hours, and the second preset temperature range is between 50° C. and 80° C.

[0022] In a second aspect, the present application also provides a method for preparing a membrane electrode, comprising:

[0023] Adding catalyst particles to a mixed solution of a perfluorosulfonic acid polymer solution, deionized water and an alcohol solution, stirring the catalyst particles at a second preset speed until the dispersion degree of the catalyst particles reaches a second preset dispersion degree, to form a catalyst slurry;

[0024] Coating the catalyst slurry on the upper and lower surfaces of the proton exchange membrane prepared by the proton exchange membrane preparation method to obtain a catalyst coated membrane;

[0025] placing the catalyst coated membrane in a hot pressing device and heating it to a third preset temperature range and then heating it for a third preset time to obtain a hot pressed catalyst coated membrane;

[0026] Gas diffusion layers are bonded to the upper and lower surfaces of the hot-pressed catalyst-coated membrane to obtain a membrane electrode with a 3D morphology structure.

[0027] In some specific embodiments, the mass ratio of the catalyst to the perfluorosulfonic acid polymer solution is between 1:1 and 5:1, and the mass ratio of the deionized water to the alcohol solution is between 1:10 and 10:1;

[0028] The molecular structure of the perfluorosulfonic acid polymer solution is the same as the molecular structure of the perfluorosulfonic acid polymer solution described in claim 1;

[0029] The second preset speed is between 8000rpm and 25000rpm;

[0030] The third preset time period is between 2 minutes and 20 minutes, and the third preset temperature range is between 120° C. and 170° C.

[0031] In a third aspect, the present application also provides a proton exchange membrane, which is prepared based on the above-mentioned proton exchange membrane preparation method.

[0032] In a fourth aspect, the present application also provides a membrane electrode, which is prepared based on the above-mentioned membrane electrode preparation method.

[0033] In a fifth aspect, the present application also provides a fuel cell comprising the above-mentioned membrane electrode.

[0034] By adopting the above technical solution, the present application provides a method for preparing a proton exchange membrane and a membrane electrode, and a proton exchange membrane, a membrane electrode and a fuel cell, which have the following beneficial effects:

[0035] The present application discloses a method for preparing a proton exchange membrane and a membrane electrode, and a proton exchange membrane, a membrane electrode and a fuel cell. The proton exchange membrane preparation method provided in the present application includes: adding a nanoparticle template to a perfluorosulfonic acid polymer solution, stirring at a first preset speed until the dispersion degree of the nanoparticle template in the perfluorosulfonic acid polymer solution reaches a first preset dispersion degree, and forming a dispersion liquid; coating the dispersion liquid on the surface of the proton exchange membrane and drying it; soaking the dried proton exchange membrane in an extraction solvent, heating it to a first preset temperature interval and continuing it for a first preset time, so that the nanoparticle template is removed, and a prefabricated proton exchange membrane with a 3D morphology structure is obtained. The present application obtains a proton exchange membrane with a 3D morphology structure by preparing a coating with a 3D morphology structure on the surface of the proton exchange membrane. By regulating the morphology structure of the proton exchange membrane, the interface impedance between the proton exchange membrane and the catalyst layer can be reduced, and at the same time, the specific surface area of ​​the catalyst layer is increased, so that the contact area between the reaction gas and the catalyst is increased, the utilization rate of the catalyst is improved, and the diffusion and mass transfer resistance of the reaction gas are reduced, and the performance of the fuel cell is further improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0037] Figure 1 A flow chart of a method for preparing a proton exchange membrane provided in an embodiment of the present application;

[0038] Figure 2 A flow chart of a membrane electrode preparation method provided in an embodiment of the present application;

[0039] Figure 3 A schematic diagram of a surface electron microscope of a proton exchange membrane with a 3D morphology structure provided in Example 1 of the present application;

[0040] Figure 4 A schematic diagram of a surface electron microscope of a proton exchange membrane with a 3D morphology structure provided in Example 2 of the present application;

[0041] Figure 5 A schematic diagram of a surface electron microscope of a proton exchange membrane with a 3D morphology structure provided in Example 3 of the present application;

[0042] Figure 6 A schematic diagram of a surface electron microscope of a proton exchange membrane with a 3D morphology structure provided in Example 4 of the present application;

[0043] Figure 7 A schematic diagram of a surface electron microscope of a proton exchange membrane with a 3D morphology structure provided in Example 5 of the present application;

[0044] Figure 8 A schematic diagram of a surface electron microscope of a proton exchange membrane with a 3D morphology structure provided in Example 6 of the present application;

[0045] Fig. 9 This is a schematic diagram of the surface electron microscope of the proton exchange membrane prepared in Comparative Example 1 of the present application;

[0046] Fig.10 This is a schematic diagram of the surface electron microscope of the proton exchange membrane prepared in Comparative Example 2 of the present application;

[0047] Fig.11 Schematic diagram of polarization curves of membrane electrodes prepared in Examples 1 to 6 of the present application and Comparative Examples 1 and 2 when applied to fuel cell performance testing. DETAILED DESCRIPTION

[0048] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0049] For the following defined terms, these definitions shall apply unless a different definition is given in the claims or elsewhere in this specification. All numerical values, whether or not explicitly indicated, are defined herein as modified by the term "about". The term "about" generally refers to a numerical range that a person of ordinary skill in the art considers to be equivalent to the stated values ​​to produce substantially the same properties, functions, results, etc. A numerical range indicated by a lower value and a higher value is defined to include all numerical values ​​included in the numerical range and all subranges included in the numerical range.

[0050] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0051] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 making creative work are within the scope of protection of the present invention.

[0052] See also Figure 1 , a method for preparing a proton exchange membrane provided in an embodiment of the present application comprises:

[0053] Add the nanoparticle template to the perfluorosulfonic acid polymer solution and stir at a first preset speed until the dispersion degree of the nanoparticle template in the perfluorosulfonic acid polymer solution reaches the first preset dispersion degree to form a dispersion liquid; specifically, the nanoparticle template can be inorganic nanoparticles, such as silicon dioxide, titanium dioxide, sodium carbonate, calcium carbonate, magnesium carbonate, sodium bicarbonate, calcium oxide, magnesium oxide, aluminum oxide, sodium chloride, magnesium chloride, potassium chloride, magnesium sulfate, etc., or organic nanoparticles, such as polystyrene nanospheres, or organic metal nanoparticles, such as ZIF-8, ZIF-67, etc., wherein the added nanoparticles as templates can be one or more of the above. The nanoparticle template is stirred in a perfluorosulfonic acid polymer solution at a first preset speed until the dispersion degree of the nanoparticle template in the perfluorosulfonic acid polymer solution reaches the first preset dispersion degree to form a dispersion liquid, wherein the first preset speed is a high speed rotation speed, preferably, the rotation speed is between 1000-10000rpm, the first preset dispersion degree is that the nanoparticle template is completely dispersed in the perfluorosulfonic acid polymer solution to form a uniform and stable dispersion liquid, the nanoparticles are evenly distributed in the entire perfluorosulfonic acid polymer solution, no large aggregates or precipitation are formed, and no particle agglomeration phenomenon is observed on a macro scale.

[0054] The dispersion is coated on the surface of the proton exchange membrane and dried; specifically, the dispersion containing nanoparticles is evenly coated on the surface of the proton exchange membrane using a coating machine or a manual method, and the coating method can be slit coating, spraying, dipping or spin coating, etc. After coating, the coated proton exchange membrane can be placed in a blast oven to dry, preferably, it can be dried continuously at a temperature of 80°C-120°C for 12 hours to form a uniform nanoparticle coating on the surface of the proton exchange membrane.

[0055] The dried proton exchange membrane is immersed in the extraction solvent, heated to the first preset temperature range and then continued for the first preset time, so that the nanoparticle template is removed to obtain a prefabricated proton exchange membrane with a 3D morphology structure. Preferably, the first preset temperature range can be between 50°C and 80°C, and the first preset time can be between 8h and 12h. Heating can allow the extraction solvent to penetrate into the proton exchange membrane more effectively, and promote the chemical reaction between the solvent and the nanoparticle template, thereby achieving the removal of the template. Appropriate heating temperature can improve the extraction efficiency, but too high a temperature may damage the structure and performance of the proton exchange membrane; sufficient time can ensure that the nanoparticle template is fully removed, too short a time may result in incomplete template removal, and too long a time may also cause unnecessary energy consumption and possible membrane damage.

[0056] The above preparation can accurately control the morphology and size of the nanostructure through the template method, realize fine regulation of the surface and internal structure of the proton exchange membrane, thereby optimizing its performance, reducing the interface impedance between the proton exchange membrane and the catalyst layer, and at the same time, increasing the specific surface area of ​​the catalyst layer, thereby increasing the contact area between the reaction gas and the catalyst, improving the utilization rate of the catalyst and reducing the diffusion and mass transfer resistance of the reaction gas, further improving the performance of the fuel cell.

[0057] In some specific embodiments, after obtaining the prefabricated proton exchange membrane having a 3D morphology structure, the method further comprises:

[0058] The prefabricated proton exchange membrane with a 3D morphology structure is immersed in a mixed solution of sulfuric acid and hydrogen peroxide solution, and heated to a second preset temperature range and then continued for a second preset time to remove the remaining inorganic metal ions therein; preferably, the second preset temperature range is 50°C-80°C, and the second preset time is 6h-12h; wherein, the sulfuric acid in the mixed solution can provide acidity, and hydrogen peroxide, as a strong oxidant, helps to dissolve and remove metal ions, and a higher temperature is used to improve the cleaning efficiency, accelerate the chemical reaction, and promote the removal of metal ions, and the time is maintained for a sufficient time to ensure that the metal ions are effectively removed, but the time cannot be too long to avoid damage to the proton exchange membrane itself.

[0059] The prefabricated proton exchange membrane is taken out and dried to obtain a proton exchange membrane with a 3D morphology structure, which can ensure the purity of the proton exchange membrane and improve its performance and durability in the fuel cell.

[0060] In some specific embodiments, the nanoparticle template comprises one or more of inorganic nanoparticles, organic nanoparticles, and organometallic nanoparticles;

[0061] Inorganic nanoparticles include one or more of silicon dioxide, titanium dioxide, sodium carbonate, calcium carbonate, magnesium carbonate, sodium bicarbonate, calcium oxide, magnesium oxide, aluminum oxide, sodium chloride, magnesium chloride, potassium chloride and magnesium sulfate; specifically, silicon dioxide (SiO2) nanoparticles have good stability and biocompatibility, and as a hard template, can be used to prepare a proton exchange membrane with a specific pore size and shape to enhance the proton conductivity and mechanical strength of the membrane; titanium dioxide (TiO2) nanoparticles have excellent photocatalytic properties, and can be used to prepare a proton exchange membrane with self-cleaning and antibacterial functions, promote the reaction on the surface of the proton exchange membrane, and improve the chemical stability and durability of the proton exchange membrane; carbonate and oxide nanoparticles such as sodium carbonate, calcium carbonate, magnesium carbonate, sodium bicarbonate, calcium oxide, magnesium oxide, aluminum oxide, sodium chloride, magnesium chloride, potassium chloride, magnesium sulfate, etc., as templates for porous structures, increase the surface area and porosity of the membrane, and as ion exchange sites, enhance the ion exchange capacity and conductivity of the proton exchange membrane, and at the same time, can provide alkalinity, which helps to improve the durability of the proton exchange membrane.

[0062] Organic nanoparticles include polystyrene nanospheres, which have good chemical stability and adjustable surface functions and can be used as soft templates to prepare proton exchange membranes with specific surface properties, thereby improving the wettability and gas permeability of the membranes.

[0063] The organic metal nanoparticles include one or more of ZIF-8 and ZIF-67; specifically, ZIF-8 and ZIF-67 are metal organic framework (MOFs) materials with unique pore structure and high specific surface area. ZIF-8 is a porous crystalline material formed by the coordination of Zn (II) and 2-methylimidazole, with adjustable pore size, highly stable structure and catalytic activity; ZIF-67 is a three-dimensional skeleton compound coordinated by Co (II) and 2-methylimidazole, with a pore size of 3.4 angstroms and an unsaturated coordinated metal center, with a highly stable structure and catalytic activity; the core-shell structure of ZIF-8 and ZIF-67 can provide abundant active sites for the reaction. At the same time, the above-mentioned nanoparticle template is not easily dissolved in the solvent and has low solubility, so that the nanoparticles exist in the solvent in a granular state, preventing the nanoparticles from dissolving in the solvent in an ionic state, and affecting the 3D morphology of the surface of the proton exchange membrane.

[0064] In some specific embodiments, the particle size d of the nanoparticle template is in the range of 10nm≤d≤1000nm, which prevents the particle size of the nanoparticle template from being too large, making the coating applied on the surface of the proton exchange membrane too thick, thereby affecting the distance of the proton transmission channel; at the same time, if the particle size of the nanoparticle template is too large, the nanoparticles are completely coated, resulting in difficulty in final removal and the formation of impurities.

[0065] The dispersion is coated on the surface of the proton exchange membrane, and the coating thickness t after drying is 50nm≤t≤5000nm. The coating thickness affects the transmission efficiency of gas and liquid in the catalytic layer. A thinner coating can provide better mass transfer performance, thereby increasing the power output of the battery. However, if the coating is too thin, it may affect its mechanical stability and durability.

[0066] The content of the nanoparticle template in the dispersed solution is between 0.1% and 50%, and the content of the nanoparticles accounts for 0.1% to 50% of the mass of the entire polymer. If the content of the nanoparticles is too low, the content of the perfluorosulfonic acid polymer solution increases, which reduces the roughness of the coating surface, thereby affecting the 3D morphology of the proton exchange membrane; if the content of the nanoparticles is too high, the content of the perfluorosulfonic acid polymer solution is too low, and after removing the nanoparticles, the gaps on the surface of the proton exchange membrane are too large.

[0067] In some specific embodiments, the first preset speed is between 1000rpm and 10000rpm; specifically, when dispersing the nanoparticle template into the perfluorosulfonic acid polymer solution, a high-speed stirring method is used to completely disperse the nanoparticle template into the perfluorosulfonic acid polymer solution. For example, a thin film gyratory high-speed stirrer can be used to achieve micronization of the nanoparticles, wherein the stirring speed can be adjusted according to the size of the nanoparticles and the viscosity of the polymer solution. Preferably, the first preset speed is between 1000rpm and 10000rpm. If the stirring speed is too low, the nanoparticle template is unevenly dispersed, and if the stirring speed is too high, the molecular chains of the perfluorosulfonic acid polymer solution will be cross-linked, making the perfluorosulfonic acid polymer solution become a thick paste, and the nanoparticle template is difficult to disperse. By using the above-mentioned rotation speed, the nanoparticle template can be completely dispersed in the perfluorosulfonic acid polymer solution.

[0068] The first preset time is 8h-12h, and the first preset temperature range is 80℃-120℃; specifically, the dried proton exchange membrane coated with nanoparticles is immersed in the extraction solvent, heated to the first preset temperature range and continued for the first preset time. Preferably, the first preset time is 8h-12h, and the first preset temperature range is 80℃-120℃; wherein the treatment time determines the contact time between the extraction solvent and the nanoparticle template, thereby affecting the removal efficiency of the template. If the treatment time is insufficient, the template may not be removed completely, affecting the performance of the subsequent proton exchange membrane; and if the treatment time is too long, the proton exchange membrane may be excessively dissolved. Proton exchange membrane, damaging its structure and performance. Long-term heating and chemical treatment may cause the membrane material to become brittle or reduce its strength, affecting its service life in the fuel cell. The heating temperature directly affects the solvent's ability to dissolve the nanoparticle template. The appropriate temperature can improve the solvent's extraction efficiency, thereby more effectively removing the template and leaving the desired 3D structure. Therefore, the heating temperature needs to be precisely controlled to avoid destroying the 3D morphology of the proton exchange membrane. If the temperature is too high, it may cause thermal degradation or structural collapse of the membrane material. If the temperature is too low, it may lead to incomplete template removal. The heating temperature also affects the chemical reaction rate between the solvent and the template. At a suitable temperature, the reaction rate is accelerated, which helps to speed up the template removal process.

[0069] The second preset time is 6h-12h, and the second preset temperature range is 50℃-80℃; specifically, the prefabricated proton exchange membrane with a 3D morphology structure is immersed in a mixed solution of sulfuric acid and hydrogen peroxide solution, and heated to the second preset temperature range and continued for the second preset time to remove the residual inorganic metal ions therein. Preferably, the second preset time is 6h-12h, and the second preset temperature range is 50℃-80℃; wherein, the treatment time will affect the efficiency of removing the residual inorganic metal ions from the proton exchange membrane, and a longer treatment time can ensure a more thorough removal of these metal ions, thereby reducing the negative impact on membrane performance. However, hydrogen peroxide, as a strong oxidant, may have Membrane materials cause oxidative stress. Too long a treatment time may increase the generation of free radicals, thereby accelerating the chemical decay of the membrane. Too long a treatment time may also reduce the durability of the proton exchange membrane, especially under high temperature and chemical corrosion. Therefore, it is necessary to accurately control the treatment time to ensure the long-term stability and performance of the membrane material. Heating can increase the temperature of the solvent and increase the movement speed of molecules, thereby increasing the reaction rate between the cleaning solution and the inorganic metal ions. The appropriate heating temperature helps to improve the cleaning efficiency and ensure the thorough removal of metal ions. However, too high a temperature may cause thermal degradation of the membrane material, affecting its mechanical strength and chemical stability. High temperature may also accelerate the aging process of the membrane material and affect its long-term durability. Heating can also enhance the chemical activity of sulfuric acid and hydrogen peroxide in the cleaning solution and improve its ability to oxidize and dissolve inorganic metal ions. However, too high a temperature may reduce the chemical stability of the cleaning solution and even cause danger. Therefore, the heating temperature needs to be controlled within a safe range to avoid dangerous reactions that strong oxidants such as hydrogen peroxide may cause at high temperatures.

[0070] See also Figure 2 , a method for preparing a membrane electrode provided in an embodiment of the present application comprises:

[0071] The catalyst particles are added to a mixed solution of a perfluorosulfonic acid polymer solution, deionized water and an alcohol solution, and the catalyst particles are stirred at a second preset speed until the dispersion degree reaches the second preset dispersion degree to form a catalyst slurry; specifically, the anode slurry generally contains about 15% by weight of a Pt-C catalyst, 40% of deionized water, 40% of a methanol-based organic solvent and 5% of a perfluorosulfonic acid polymer solution as a binder, and the cathode slurry contains about 20% of a Pt-C catalyst, 35% of deionized water, 35% of a methanol-based organic solvent and 10% of a perfluorosulfonic acid polymer solution; wherein, a paddle stirrer, a ball stirrer, an ultrasonic disperser and the like can be used for dispersion; preferably, a second preset speed of 8000rpm-25000rpm is used for high-speed stirring to form a uniform and stable dispersion to prepare the catalyst slurry.

[0072] The catalyst slurry is coated on the upper and lower surfaces of the proton exchange membrane prepared by the above-mentioned proton exchange membrane preparation method to obtain a catalyst coated membrane; specifically, the coating can be carried out by spraying, transfer printing or direct coating, etc.; among them, spraying can achieve rapid and uniform distribution of the catalyst slurry, which is suitable for large-scale production. By adjusting various parameters of the spraying equipment, such as spraying speed, pressure and distance, the thickness and uniformity of the coating can be accurately controlled. Transfer printing coats the catalyst slurry on a special transfer membrane, and then transfers the catalyst layer to the proton exchange membrane by hot pressing. During the transfer printing process, the selection of the transfer membrane and the control of the hot pressing conditions are very critical to ensure that the catalyst layer can be completely transferred from the transfer membrane to the proton exchange membrane while maintaining its structure and performance; direct coating is a simple and direct method, in which the catalyst slurry is directly coated on the proton exchange membrane by brushing, scraping or other coating tools. It is easy to operate and suitable for laboratory-scale research and small-scale production.

[0073] The catalyst-coated membrane is placed in a hot pressing device and heated to a third preset temperature interval and continued for a third preset time to obtain a hot pressed catalyst-coated membrane; preferably, the third preset temperature interval is between 120°C and 170°C, and the third preset time is between 2min and 20min. The appropriate heating temperature and heating time can enhance the bonding strength between the catalyst layer and the proton exchange membrane. However, if the temperature is too low or the duration is too short, insufficient bonding may result, while if the temperature is too high or the duration is too long, thermal degradation or structural changes of the membrane material may occur, affecting its performance. Through hot pressing, the bonding strength between the catalyst layer and the proton exchange membrane can be enhanced to ensure that the catalyst layer will not fall off easily during the operation of the fuel cell, reduce the interface resistance, improve the catalyst utilization rate, enhance the structural stability, and thus improve the performance and durability of the fuel cell.

[0074] The gas diffusion layer is attached to the upper and lower surfaces of the hot-pressed catalyst-coated membrane to obtain a membrane electrode with a 3D morphology structure. The 3D structural design can improve the transmission of the reaction gas, increase the supply efficiency of oxygen and fuel, and thus increase the output power density of the battery.

[0075] In some specific embodiments, the mass ratio of the catalyst to the perfluorosulfonic acid polymer solution is between 1:1 and 5:1, and the mass ratio of deionized water to the alcohol solution is between 1:10 and 10:1;

[0076] The molecular structure of the perfluorosulfonic acid polymer solution added to the catalyst is the same as the molecular structure of the perfluorosulfonic acid polymer solution added to the above-mentioned nanoparticle template; if the molecular chain structures of the perfluorosulfonic acid polymer solutions are the same, during high-temperature treatment, the molecular chains of the perfluorosulfonic acid polymer solutions are cross-linked, so that the contact resistance between each other is small, thereby improving the conductivity; if the molecular chain structures of the perfluorosulfonic acid polymer solutions are different, an interface effect is formed during the cross-linking process, thereby affecting the conductivity.

[0077] The second preset speed is between 8000rpm and 25000rpm. Specifically, the catalyst particles are added to a mixed solution of a perfluorosulfonic acid polymer solution, deionized water and an alcohol solution, and the catalyst particles are stirred at the second preset speed until the dispersion degree reaches the second preset dispersion degree to form a catalyst slurry; wherein, preferably, the second preset speed is between 8000rpm and 25000rpm. An appropriate stirring speed can ensure that the catalyst particles are uniformly dispersed in the mixed solution of the perfluorosulfonic acid polymer solution, deionized water and an alcohol solution, avoiding aggregation, thereby improving the uniformity of the catalyst slurry, and the uniform dispersion of the catalyst particles helps to increase the contact area between the particles and the reactants, thereby improving the catalytic efficiency, and the uniformly dispersed catalyst particles are conducive to preventing the particles from agglomerating and sintering, thereby extending the service life of the catalyst. In a fuel cell, the uniform dispersion of the catalyst slurry can improve the uniformity of the catalyst layer structure, high porosity, high utilization rate, thereby improving the electrical performance and durability of the fuel cell membrane electrode. By adjusting the stirring speed, the particle dispersion can be controlled and agglomeration can be avoided.

[0078] The third preset time is between 2min and 20min, and the third preset temperature interval is between 120℃ and 170℃; specifically, the catalyst coating film is placed in a hot pressing device and heated to the third preset temperature interval and then continued for the third preset time to obtain a hot pressed catalyst coating film; preferably, the third preset time is between 2min and 20min, and the third preset temperature interval is between 120℃ and 170℃; the appropriate heating temperature helps to maintain the smaller size and good dispersion state of the catalyst particles, thereby improving the quality of the catalytic layer, optimizing the pore structure of the catalytic layer, and improving its mass transfer efficiency and electrochemical performance; and the heating time will affect the aggregation state of the particles in the catalyst slurry, and the appropriate heating time can promote the adsorption of ionomers on the catalyst surface, thereby improving the stability of the slurry. Excessive heating time may cause excessive aggregation of catalyst particles, affecting the uniformity of the slurry and the performance of the catalytic layer. Therefore, precise control of the heating temperature and duration is crucial for the preparation of high-performance catalyst slurry.

[0079] A proton exchange membrane provided in an embodiment of the present application is prepared based on the above-mentioned method for preparing a proton exchange membrane. By adjusting the surface of the proton exchange membrane to have a 3D structure, on the one hand, the contact area between the proton exchange membrane and the catalyst layer can be increased, thereby greatly reducing the interface impedance between the proton exchange membrane and the catalyst layer; on the other hand, the catalyst layer is attached to the surface of the proton exchange membrane to form a 3D morphology structure, which can be beneficial to the discharge of water, increase the three-phase interface between the reaction gas and the active catalyst and the ion-conducting polymer, and further reduce the mass transfer impedance. At the same time, the 3D structure can also increase the specific surface area of ​​the catalyst layer, which is beneficial to the full contact between the reaction gas and the catalyst, further increase the active area of ​​the catalyst, and further improve the utilization efficiency of the catalyst.

[0080] The present application provides a membrane electrode, which is prepared based on the above-mentioned membrane electrode preparation method. The membrane electrode with a 3D morphology is prepared by modifying the surface of the proton exchange membrane. The preparation process is simple, low-cost, high-efficiency, and conducive to large-scale industrial application.

[0081] A fuel cell provided in an embodiment of the present application includes the above-mentioned membrane electrode, which has a 3D morphology structure, which can improve the performance of the fuel cell, reduce costs, and enhance durability.

[0082] The following is a specific example to illustrate the method for preparing the membrane electrode of the present application and the prepared membrane electrode.

[0083] Embodiment 1

[0084] 0.1 g of nanoparticle silica was weighed and mixed with 10 g of 20% perfluorosulfonic acid polymer solution, and then dispersed under high-speed stirring for 6 hours to form a uniform and stable dispersion. The dispersion was then coated on the upper and lower surfaces of a Gore membrane (M735.18) and dried at 80°C for 12 hours to prepare a modified proton exchange membrane, wherein the coating thickness on the upper and lower surfaces after drying was 300 nm.

[0085] The modified proton exchange membrane was immersed in a 5 mol / L sodium hydroxide solution at 80°C for 8 hours to completely remove the nanoparticle silica and obtain a proton exchange membrane with a 3D morphology structure. The proton exchange membrane with a 3D morphology structure was washed 4 times with deionized water, and then immersed in a mixed solution of 5% hydrogen peroxide and 0.5 mol / L sulfuric acid at 80°C for 12 hours to remove the remaining inorganic metal ions, and then dried at 80°C for 12 hours.

[0086] A certain mass of Pt / C (50%wt Pt) catalyst, deionized water, isopropanol, and perfluorosulfonic acid polymer solution were fully mixed and prepared into catalyst slurry by ball milling and stirring for 10h. The mass ratio of Pt / C catalyst to perfluorosulfonic acid polymer is 3:1, the mass ratio of deionized water to isopropanol is 5:3, the solid mass fraction of the catalyst slurry is 16%, the mass of Pt / C catalyst is 1.2g, the mass of 20% perfluorosulfonic acid polymer solution is 2g, the mass of deionized water is 4.25g, and the mass of isopropanol is 3.15g. The catalyst was coated on the upper and lower surfaces of the proton exchange membrane with a 3D morphology by transfer printing (including hot pressing) (the Pt loading on the cathode side is 0.4mg / cm 2 ; Anode side loading 0.1mg / cm 2 ). Then, it is hot pressed with the frame membrane and the gas diffusion layer to form a membrane electrode with a 3D morphology structure. The surface electron microscope diagram of the proton exchange membrane with a 3D morphology structure is shown in the figure Figure 3 shown.

[0087] Embodiment 2

[0088] 0.1 g of nanoparticle silica was weighed and mixed with 10 g of 20% perfluorosulfonic acid polymer solution, and then dispersed under high-speed stirring for 6 hours to form a uniform and stable dispersion. The dispersion was then coated on the upper and lower surfaces of a Gore membrane (M735.18) and dried at 80°C for 12 hours to prepare a modified proton exchange membrane, wherein the coating thickness on the upper and lower surfaces after drying was 300 nm.

[0089] The modified proton exchange membrane was immersed in a 5 mol / L sodium hydroxide solution at 80°C for 8 hours to completely remove the nanoparticle silica to obtain a proton exchange membrane with a 3D morphology structure. The proton exchange membrane with a 3D morphology structure was washed four times with deionized water, and then immersed in a mixed solution of 5% hydrogen peroxide and 0.5 mol / L sulfuric acid at 80°C for 12 hours to remove the remaining inorganic metal ions, and then dried at 80°C for 12 hours.

[0090] A certain mass of Pt / C (50%wt Pt) catalyst, deionized water, isopropanol, and perfluorosulfonic acid polymer solution were fully mixed and prepared into catalyst slurry by high-speed stirring for 2h. The mass ratio of Pt / C catalyst to perfluorosulfonic acid polymer is 2:1, and the mass ratio of deionized water to isopropanol is 1:1. The solid content of the catalyst slurry is 2%, with a mass of 1.2g of Pt / C catalyst, 20% of the perfluorosulfonic acid polymer solution, 39g of deionized water, and 39g of isopropanol. The catalyst slurry was coated on the upper and lower surfaces of the proton exchange membrane with a 3D morphology structure by ultrasonic spraying (the Pt loading on the cathode side was 0.4mg / cm 2 ; Anode side loading 0.1mg / cm 2 ), the catalyst coated membrane is placed in a hot press device and hot pressed at 150°C for 10 minutes to make the proton exchange membrane and the coated perfluorosulfonic acid layer fuse more tightly and reduce the interface resistance. Then, it is hot pressed with the frame membrane and the gas diffusion layer to form a membrane electrode with a 3D morphology structure. The surface electron microscope diagram of the proton exchange membrane with a 3D morphology structure is shown in the figure Figure 4 shown.

[0091] Embodiment 3

[0092] 0.1 g of nanoparticle polystyrene microspheres were weighed and mixed with 10 g of 20% perfluorosulfonic acid polymer solution, and then dispersed under high-speed stirring for 6 hours to form a uniform and stable dispersion. The dispersion was then coated on the upper and lower surfaces of a Gore membrane (M735.18) and dried at 80°C for 12 hours to prepare a modified proton exchange membrane, wherein the coating thickness on the upper and lower surfaces after drying was 300 nm.

[0093] The modified proton exchange membrane was immersed in an acetone solution and stirred for 12 hours to completely remove the nanoparticle polystyrene microspheres to obtain a proton exchange membrane with a 3D morphology structure. The proton exchange membrane with a 3D morphology structure was washed 4 times with deionized water, and then immersed in a mixed solution of 5% hydrogen peroxide and 0.5 mol / L sulfuric acid at 80°C for 12 hours to remove the remaining inorganic metal ions, and then dried at 80°C for 12 hours.

[0094] A certain mass of Pt / C (50%wt Pt) catalyst, deionized water, isopropanol, and perfluorosulfonic acid polymer solution were fully mixed and prepared into catalyst slurry by high-speed stirring for 10 hours. The mass ratio of Pt / C catalyst to perfluorosulfonic acid polymer is 2:1, and the mass ratio of deionized water to isopropanol is 5:3. The solid content of the catalyst slurry is 16%, with a mass of 1.2g of Pt / C catalyst, a mass of 20% perfluorosulfonic acid polymer solution, a mass of 4.25g of deionized water, and 3.15g of isopropanol. The catalyst was coated on the upper and lower surfaces of the proton exchange membrane with a 3D morphology by transfer printing (the Pt loading on the cathode side was 0.4mg / cm 2 ; Anode side loading 0.1mg / cm 2 ), the catalyst coated membrane is placed in a hot press device and hot pressed at 150°C for 2 minutes. Then, it is hot pressed with the frame membrane and the gas diffusion layer to form a membrane electrode with a 3D morphology structure. The surface electron microscopy diagram of the proton exchange membrane with a 3D morphology structure is shown in the figure Figure 5 shown.

[0095] Embodiment 4

[0096] 0.1 g of nanoparticle polystyrene microspheres were weighed, mixed with 10 g of 20% perfluorosulfonic acid polymer solution, and dispersed under high-speed stirring for 6 hours to form a uniform and stable dispersion. The dispersion was then coated on the upper and lower surfaces of a Gore membrane (735.18) and dried at 80°C for 12 hours to prepare a modified proton exchange membrane, wherein the coating thickness on the upper and lower surfaces after drying was 300 nm.

[0097] The modified proton exchange membrane was immersed in an acetone solution and stirred for 12 hours to completely remove the nanoparticle polystyrene microspheres to obtain a proton exchange membrane with a 3D morphology structure. The proton exchange membrane with a 3D morphology structure was washed 4 times with deionized water, and then immersed in a mixed solution of 5% hydrogen peroxide and 0.5 mol / L sulfuric acid at 80°C for 12 hours to remove the remaining inorganic metal ions, and then dried at 80°C for 12 hours.

[0098] A certain mass of Pt / C (50%wt Pt) catalyst, deionized water, isopropanol, and perfluorosulfonic acid polymer solution were fully mixed and prepared into catalyst slurry by high-speed stirring for 2h. The mass ratio of Pt / C catalyst to perfluorosulfonic acid polymer is 2:1, and the mass ratio of deionized water to isopropanol is 1:1. The solid content of the catalyst slurry is 2%, with a mass of 1.2g of Pt / C catalyst, 20% of the perfluorosulfonic acid polymer solution, 39g of deionized water, and 39g of isopropanol. The catalyst slurry was coated on the upper and lower surfaces of the proton exchange membrane with a 3D morphology structure by ultrasonic spraying (the Pt loading on the cathode side was 0.4mg / cm 2 ; Anode side loading 0.1mg / cm 2 ), the catalyst coated membrane was placed in a hot press device and hot pressed at 150°C for 10 minutes. Then, it was hot pressed with the frame membrane and the gas diffusion layer to form a membrane electrode with a 3D morphology structure. The surface electron microscopy diagram of the proton exchange membrane with a 3D morphology structure is shown in the figure Figure 6 shown.

[0099] Embodiment 5

[0100] 0.5 g of nanoparticle sodium chloride was weighed, mixed with 10 g of 20% perfluorosulfonic acid polymer solution, and dispersed under high-speed stirring for 6 hours to form a uniform and stable dispersion. The dispersion was then coated on the upper and lower surfaces of a Gore membrane (735.18) and dried at 80°C for 12 hours to prepare a modified proton exchange membrane, wherein the coating thickness on the upper and lower surfaces after drying was 300 nm.

[0101] The modified proton exchange membrane was immersed in deionized water at 80°C for 8 hours to completely remove the nanoparticle sodium chloride to prepare a proton exchange membrane with a 3D morphology structure. The proton exchange membrane with a 3D morphology structure was washed with deionized water for 4 times, immersed in a mixed solution of 5% hydrogen peroxide and 0.5 mol / L sulfuric acid, boiled at 80°C for 12 hours to remove the remaining inorganic metal ions, and then dried at 80°C for 12 hours.

[0102] A certain mass of Pt / C (47%wt Pt) catalyst, deionized water, isopropanol, and perfluorosulfonic acid polymer solution were fully mixed and prepared into catalyst slurry by high-speed stirring for 2h. The mass ratio of Pt / C catalyst to perfluorosulfonic acid polymer is 2:1, and the mass ratio of deionized water to isopropanol is 1:1. The solid content of the catalyst slurry is 16%, with a mass of 1.2g of Pt / C catalyst, a mass of 20% perfluorosulfonic acid polymer solution, a mass of 4.25g of deionized water, and 3.15g of isopropanol. The catalyst was coated on the upper and lower surfaces of the proton exchange membrane with a 3D morphology by transfer printing (the Pt loading on the cathode side was 0.4mg / cm 2 ; Anode side loading 0.1mg / cm 2 ). Then, it is hot pressed with the frame membrane and the gas diffusion layer to form a membrane electrode with a 3D morphology structure. The surface electron microscope diagram of the proton exchange membrane with a 3D morphology structure is shown in the figure Figure 7 shown.

[0103] Embodiment 6

[0104] 0.5 g of nanoparticle sodium chloride was weighed, mixed with 10 g of 20% perfluorosulfonic acid polymer solution, and dispersed under high-speed stirring for 6 hours to form a uniform and stable dispersion. The dispersion was then coated on the upper and lower surfaces of a Gore membrane (735.18) and dried at 80°C for 12 hours to prepare a modified proton exchange membrane, wherein the coating thickness on the upper and lower surfaces after drying was 300 nm.

[0105] The modified proton exchange membrane was immersed in deionized water at 80°C for 8 hours to completely remove the nanoparticle sodium chloride to obtain a proton exchange membrane with a 3D morphology structure. The proton exchange membrane with a 3D morphology structure was washed 4 times with deionized water, and then immersed in a mixed solution of 5% hydrogen peroxide and 0.5 mol / L sulfuric acid at 80°C for 12 hours to remove the remaining inorganic metal ions, and then dried at 80°C for 12 hours.

[0106] A certain mass of Pt / C (47%wt Pt) catalyst, deionized water, isopropanol, and perfluorosulfonic acid polymer solution were fully mixed and uniformly mixed, and the catalyst slurry was prepared by high-speed stirring for 2h. The mass ratio of Pt / C catalyst to perfluorosulfonic acid polymer is 2:1, and the mass ratio of deionized water: isopropanol is 1:1. The solid content of the catalyst slurry is 2%, the mass of Pt / C catalyst is 1.2g, the mass of 20% perfluorosulfonic acid polymer solution is 2g, the mass of deionized water is 39g, and the mass of isopropanol is 39g. The catalyst slurry is coated on the upper and lower surfaces of the proton exchange membrane with a 3D morphology structure by ultrasonic spraying (wherein the Pt loading on the cathode side is 0.4mg / cm2; the loading on the anode side is 0.1mg / cm2), and the catalyst coated membrane is placed in a hot pressing device and hot pressed at 150°C for 10min. Then it is hot pressed with the frame membrane and the gas diffusion layer into a membrane electrode with a 3D morphology structure. Among them, the surface electron microscope schematic diagram of the proton exchange membrane with a 3D morphology structure is shown in the figure Figure 8 shown.

[0107] Comparative Example 1

[0108] The Gore membrane (735.18) was immersed in a mixed solution of 5% hydrogen peroxide and 0.5 mol / L sulfuric acid at 80° C. for 12 hours to remove the remaining inorganic metal ions, and then dried at 80° C. for 12 hours.

[0109] A certain mass of Pt / C (47%wt Pt) catalyst, deionized water, isopropanol, and perfluorosulfonic acid polymer solution were fully mixed and prepared into catalyst slurry by high-speed stirring for 2h. The mass ratio of Pt / C catalyst to perfluorosulfonic acid polymer is 3:1, and the mass ratio of deionized water to isopropanol is 1:1. The solid content of the catalyst slurry is 16%, with a mass of 1.2g of Pt / C catalyst, a mass of 20% perfluorosulfonic acid polymer solution, a mass of 4.25g of deionized water, and 3.15g of isopropanol. The catalyst was coated on the upper and lower surfaces of the proton exchange membrane with a 3D morphology by transfer printing (the Pt loading on the cathode side was 0.4mg / cm 2 ; Anode side loading 0.1mg / cm 2 ), and then hot pressed with the frame membrane and gas diffusion layer to form a membrane electrode. The surface electron microscope diagram of the unmodified proton exchange membrane is shown in Fig. 9 shown.

[0110] Comparative Example 2

[0111] The Gore membrane (735.18) was immersed in a mixed solution of 5% hydrogen peroxide and 0.5 mol / L sulfuric acid at 80°C for 12 hours to remove the remaining inorganic metal ions, and then dried at 80°C for 12 hours.

[0112] A certain mass of Pt / C (47%wt Pt) catalyst, deionized water, isopropanol, and perfluorosulfonic acid polymer solution were fully mixed and uniformly mixed, and the catalyst slurry was prepared by high-speed stirring for 2 hours. The mass ratio of Pt / C catalyst to perfluorosulfonic acid polymer is 2:1, and the mass ratio of deionized water to isopropanol is 1:1. The solid content of the catalyst slurry is 2%, with a mass of 1.2g of Pt / C catalyst, 20% of the perfluorosulfonic acid polymer solution, 39g of deionized water, and 39g of isopropanol. The catalyst slurry was coated on the upper and lower surfaces of the proton exchange membrane with a 3D morphology structure by ultrasonic spraying (the Pt loading on the cathode side was 0.4mg / cm 2 ; Anode side loading 0.1mg / cm 2 ), the catalyst coated membrane is placed in a hot press device and hot pressed at 120-170°C for 10 minutes. Then, it is hot pressed with the frame membrane and the gas diffusion layer to form a membrane electrode. The surface electron microscopy diagram of the unmodified proton exchange membrane is shown in the figure Fig.10 shown.

[0113] Figure 3-8 Schematic diagram of the electron microscope surface of the proton exchange membrane of Examples 1 to 6, and Comparative Examples 1 and 2 Figure 9-10 By comparing the electron microscope schematic diagram of the proton exchange membrane surface, it can be seen that the proton exchange membrane prepared by the nanoparticle hard template method has a clear 3D morphology structure.

[0114] The membrane electrodes prepared in Examples 1 to 6, Comparative Examples 1 and 2 were assembled into fuel cells, and performance tests were performed. The polarization curve test was as follows: Fig.11 As shown; the test conditions are: temperature 80°C, humidity 100%, the flow rate of hydrogen and air follows a stoichiometric ratio of 1.3 / 2.0, the back pressure at the hydrogen end is 0.2MPa, and the back pressure at the air end is 0.2MPa.

[0115] from Fig.11It is known that: under the same current density, the voltage of embodiments 1 to 6 of the present application is greater than that of comparative examples 1 and 2, and the power density of embodiments 1 to 6 is also higher than that of comparative examples 1 and 2. At the same time, the maximum power density of embodiments 1 to 6 is much higher than that of comparative examples 1 and 2. Therefore, it can be proved that the performance of the fuel cell of embodiments 1 to 6 of the present application is better than that of the fuel cell of comparative examples 1 and 2. The membrane electrode with 3D structural morphology prepared by embodiments 1 to 6 of the present application can not only increase the specific surface area of ​​the catalyst layer and improve the utilization rate of the catalyst; but also increase the contact area between the catalyst layer and the proton exchange membrane, thereby reducing the contact impedance of the fuel cell; at the same time, it is also beneficial to remove water from the fuel cell and improve the gas permeability, thereby greatly improving the electrochemical performance of the fuel cell.

[0116] The above description has fully disclosed the specific embodiments of the present invention. It should be pointed out that any changes made by those skilled in the art to the specific embodiments of the present invention do not deviate from the scope of the claims of the present invention. Accordingly, the scope of the claims of the present invention is not limited to the above specific embodiments.

Claims

1. A method for preparing a proton exchange membrane, characterized in that: include: Adding the nanoparticle template to the perfluorosulfonic acid polymer solution, stirring at a first preset speed until the dispersion degree of the nanoparticle template in the perfluorosulfonic acid polymer solution reaches a first preset dispersion degree, to form a dispersion liquid; coating the dispersion on the surface of a proton exchange membrane and drying it; The dried proton exchange membrane is immersed in an extraction solvent, heated to a first preset temperature range and then continued for a first preset time, so that the nanoparticle template is removed to obtain a prefabricated proton exchange membrane with a 3D morphology structure.

2. The method for preparing a proton exchange membrane according to claim 1, characterized in that: After obtaining the prefabricated proton exchange membrane with a 3D morphology structure, the method further comprises: Immersing the prefabricated proton exchange membrane with the 3D morphology structure in a mixed solution of sulfuric acid and hydrogen peroxide solution, heating to a second preset temperature range and then continuing for a second preset time to remove the remaining inorganic metal ions therein; The prefabricated proton exchange membrane is taken out and dried to obtain a proton exchange membrane with a 3D morphology structure.

3. The method for preparing a proton exchange membrane according to claim 1, characterized in that: The nanoparticle template includes one or more of inorganic nanoparticles, organic nanoparticles and organometallic nanoparticles; The inorganic nanoparticles include one or more of silicon dioxide, titanium dioxide, sodium carbonate, calcium carbonate, magnesium carbonate, sodium bicarbonate, calcium oxide, magnesium oxide, aluminum oxide, sodium chloride, magnesium chloride, potassium chloride and magnesium sulfate; The organic nanoparticles include polystyrene nanospheres; The organometallic nanoparticles include one or more of ZIF-8 and ZIF-67.

4. The method for preparing a proton exchange membrane according to claim 1, characterized in that: The particle size d of the nanoparticle template is 10nm≤d≤1000nm; The dispersion is coated on the surface of the proton exchange membrane, and the coating thickness t after drying is 50nm≤t≤5000nm; The content of the nanoparticle template in the dispersed solution is between 0.1% and 50%.

5. The method for preparing a proton exchange membrane according to claim 1, characterized in that: The first preset speed is between 1000 rpm and 10000 rpm; The first preset time is between 8 hours and 12 hours, and the first preset temperature range is between 80° C. and 120° C.; The second preset time period is between 6 hours and 12 hours, and the second preset temperature range is between 50° C. and 80° C.

6. A method for preparing a membrane electrode, characterized in that: include: Adding catalyst particles to a mixed solution of a perfluorosulfonic acid polymer solution, deionized water and an alcohol solution, stirring the catalyst particles at a second preset speed until the dispersion degree of the catalyst particles reaches a second preset dispersion degree, to form a catalyst slurry; Coating the catalyst slurry on the upper and lower surfaces of the proton exchange membrane prepared by the method for preparing a proton exchange membrane according to any one of claims 1 to 5 to obtain a catalyst-coated membrane; placing the catalyst coated membrane in a hot pressing device and heating it to a third preset temperature range and then heating it for a third preset time to obtain a hot pressed catalyst coated membrane; Gas diffusion layers are bonded to the upper and lower surfaces of the hot-pressed catalyst-coated membrane to obtain a membrane electrode with a 3D morphology structure.

7. The method for preparing a membrane electrode according to claim 6, characterized in that: The mass ratio of the catalyst to the perfluorosulfonic acid polymer solution is between 1:1 and 5:1, and the mass ratio of the deionized water to the alcohol solution is between 1:10 and 10:1; The molecular structure of the perfluorosulfonic acid polymer solution is the same as the molecular structure of the perfluorosulfonic acid polymer solution described in claim 1; The second preset speed is between 8000rpm and 25000rpm; The third preset time period is between 2 minutes and 20 minutes, and the third preset temperature range is between 120° C. and 170° C.

8. A proton exchange membrane, characterized in that: The proton exchange membrane is prepared based on the method for preparing a proton exchange membrane according to any one of claims 1 to 5.

9. A membrane electrode, characterized in that: The membrane electrode is prepared based on the membrane electrode preparation method described in claim 6 or 7.

10. A fuel cell, characterized in that: The invention comprises the membrane electrode as claimed in claim 9.

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