Membrane electrode for fuel cell and preparation method thereof

Abstract

The present invention discloses a membrane electrode for fuel cells and a preparation method thereof. It comprises a proton exchange membrane and cathode and anode catalyst layers located on both sides of the proton exchange membrane, wherein the cathode catalyst layer contains a metal mesh, the metal mesh is attached with a base film, and the catalyst is coated on the metal mesh. A layer of metal mesh is attached to the cathode catalyst layer in the membrane electrode of the present invention, which can improve the strength of the entire membrane electrode and can adapt to a higher stress preparation and use environment. At the same time, the electrical conductivity of the catalyst layer can be improved, thereby reducing the internal resistance of the electrode and increasing the electrical power. The preparation method of the present invention ultrasonically sprays the cathode catalyst layer slurry onto the metal mesh, and then thermally transfers it to the proton exchange membrane. Catalysts of different particle sizes can be screened to prepare a catalyst layer with a gradient structure, so that the catalyst can be utilized more efficiently, thereby improving the power density of the entire electrode. The preparation process of the present invention is mature, suitable for mass production, and reduces the cost of each kilowatt membrane electrode.

Description

Technical Field

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

[0002] Proton exchange membrane fuel cell (PEMFC) is a highly efficient energy conversion device that can directly convert the chemical energy stored in hydrogen fuel and oxidant into electrical energy through electrochemical reactions. It has the characteristics of being green and environmentally friendly, high specific energy, fast start-up at low temperatures and highly stable operation, and is considered to be an ideal power source to replace internal combustion engines.

[0003] However, the current industrialization of PEMFCs still faces problems such as high costs and short lifespans. There are two main approaches to improving PEMFC performance and reducing system costs: one is to improve the intrinsic activity of the catalyst by reducing the amount of precious metal Pt used, thereby improving catalyst activity and stability, through methods such as changing the carrier and preparing alloy catalysts. However, this approach is unlikely to fully improve PEMFC performance, as the electrochemical reaction process is also affected by many factors, including the three-phase interface and the mass transfer channels for electrons, protons, gases, and water. The other approach is to improve PEMFC performance by exploring new membrane electrode preparation methods and processes from the perspective of membrane electrode and catalyst layer structure. This approach involves a wide range of factors, can coordinate the reaction process overall, and improve fuel cell performance, thus becoming a research focus.

[0004] The membrane electrode (MEA) is the core component of the proton exchange membrane fuel cell (PEMFC). It provides microchannels for multiphase mass transfer and a site for electrochemical reactions. Its performance directly determines the performance of the PEMFC. Currently, the best performing MEA is the nanostructured thin films (NSTF) electrode developed by 3M, whose Pt content can be reduced to 0.15 mg / cm 2 However, it is prone to flooding and durability issues need to be addressed. Therefore, the preparation of low-cost, high-performance, and durable MEAs has become a hot research topic that has attracted widespread attention from researchers around the world.

[0005] The MEA primarily consists of a gas diffusion layer (GDL), a catalyst layer (CL), and a proton exchange membrane (PEM). In fuel cell membrane electrode systems, the PEM is typically constructed from a microporous PTFE substrate coated with an ionomer, with a total thickness of less than 8-20 μm. This thin membrane exhibits low strength and is prone to swelling, making it susceptible to damage during transport, preparation, and use. Currently, the requirements for the preparation and application of PEMs are stringent. In automotive fuel cell systems, the operating conditions of the membrane electrode are complex, and a large pressure difference between the anode and cathode can damage the membrane.

[0006] A major component of existing membrane electrode catalyst layers is ionomer, which is a medium for proton conduction and must be in close contact with the catalyst. The ionomer's insulation to electrons increases the ohmic resistance of the catalyst layer, especially the cathode catalyst layer.

[0007] The ideal catalyst particle size distribution in the solution of fuel cell catalyst slurry after homogenization is between 400nm-20μm. Some undispersed particles have a particle size of ≥30μm, which is not evenly coated on the proton membrane to form a catalytic layer, but does not form a reasonable distribution and does not maximize efficiency. Summary of the Invention

[0008] The present invention aims to provide a membrane electrode for fuel cells with high power density, high conductivity and high strength. The present invention also provides a method for preparing the membrane electrode for fuel cells.

[0009] The present invention is achieved through the following solutions:

[0010] A membrane electrode for a fuel cell comprises a proton exchange membrane and a cathode catalyst layer and an anode catalyst layer located on both sides of the proton exchange membrane. The cathode catalyst layer comprises a metal mesh with a base film attached thereto. The catalyst is coated on the metal mesh.

[0011] Preferably, the metal mesh is a stainless steel mesh or a titanium mesh; the wire diameter of the metal mesh is 10-30 μm, and the pore size is 10-33 μm (equivalent to 400-1000 mesh). The metal mesh also has electrical corrosion resistance. The mesh size is selected based on the properties of the catalyst and ion exchange resin material. After the metal mesh is ultrasonically sprayed with catalyst slurry, smaller particles will penetrate under the mesh. Catalyst particles exceeding the mesh pore size will float on the mesh surface to form two catalytic layers, thereby improving the product's electrical conductivity and electrical properties.

[0012] Preferably, the base membrane is a PTFE membrane with a thickness of 0.1-1 mm.

[0013] The cathode and anode catalyst layers respectively include a catalyst and an ion exchange resin, wherein the catalyst is a ternary platinum alloy catalyst, and the mass ratio of the catalyst to the ion exchange resin is 1-10:1; the ion exchange resin is one of DuPont D520, DuPont D2020, Solvay D83 and D79.

[0014] Preferably, the catalyst is a platinum-carbon catalyst or a platinum-cobalt-carbon catalyst, the platinum mass content of the catalyst is 40%-60%; the platinum loading of the cathode catalyst layer is 0.1-0.35 mg / cm 2 The platinum loading of the anode catalyst layer is 0.04-0.06 mg / cm 2 Parameters within this range can take into account both performance and cost, and can improve the performance of membrane electrode power density and thus reduce costs.

[0015] The present invention also provides a method for preparing the membrane electrode for fuel cell, comprising the following steps:

[0016] (1) After mixing an organic solvent and an ion exchange resin, a catalyst is added to obtain a cathode catalyst slurry and an anode catalyst slurry;

[0017] (2) The cathode catalyst slurry obtained in step (1) is first coated on a metal wire mesh with a base film, and then thermally transferred to one side of the proton exchange membrane; the anode catalyst slurry is coated on the other side of the proton exchange membrane, thereby obtaining a membrane electrode for a fuel cell;

[0018] Wherein, the organic solvent in step (1) is at least one of ethanol, n-propanol, isopropanol and n-butanol, and the catalyst is a ternary platinum alloy catalyst.

[0019] Specifically, the specific steps of step (1) are: (I) mixing an organic solvent, water and an ion exchange resin to obtain a mixed solution; (II) mixing the mixed solution in (I) with a catalyst to obtain cathode and anode catalyst slurries;

[0020] Wherein, the mass ratio of the organic solvent to water in step (I) is 1:0.1-5, and the solid content of the mixed solution in step (II) is 0.5%-5%.

[0021] Preferably, the cathode and anode catalyst slurries have a particle size of 0.5-50 μm; the ternary platinum alloy catalyst is TKK brand TEC10E40E, TEC10E60TPM, or TEC10E50E, and has a platinum content of 50% by weight. After the catalyst slurry is ultrasonically sprayed onto the metal mesh, smaller particles penetrate beneath the mesh, while catalyst particles exceeding the mesh pore size float on the mesh surface, forming two catalytic layers.

[0022] Specifically, the coating treatment conditions in step (2) are: heating plate 75-90 ° C, slurry spraying flow rate 0.5-7.2 ml / min, nozzle height 20-50 mm, nozzle moving speed 80-500 mm / min, spraying interval 5-10 mm for spraying operation, adjacent spraying tracks are set to overlap 5%-15%, and the spraying direction is perpendicular to the gas flow direction of the bipolar plate.

[0023] The processing conditions of thermal transfer are: using a hot press, place the membrane electrode with diffusion layers on both sides between press plates with a parallelism of 3 wires, and hot press at 100-150°C for 30-240s.

[0024] Beneficial effects of the present invention:

[0025] (1) A layer of metal mesh is attached to the cathode catalyst layer in the membrane electrode of the present invention, which can improve the strength of the entire membrane electrode and adapt to higher stress preparation and use environments.

[0026] (2) The metal mesh in the membrane electrode of the present invention covers the entire cathode catalyst layer, which can improve the conductivity of the catalyst layer, thereby reducing the internal resistance of the electrode and increasing the electrical power.

[0027] (3) The preparation method of the present invention ultrasonically sprays the cathode catalyst layer slurry onto a metal wire mesh and then thermally transfers it to a proton exchange membrane. Catalysts of different particle sizes can be screened to prepare a catalytic layer with a gradient structure, allowing the catalyst to be utilized more efficiently and improving the power density of the entire electrode.

[0028] (4) The preparation method of the present invention has a simple structure and a mature preparation process, is suitable for mass production, improves power density, and reduces the cost per kilowatt of membrane electrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The fuel cell membrane electrodes prepared in Examples 1-3 and Comparative Examples 1-3 were assembled into cells and IV curves were measured. DETAILED DESCRIPTION

[0030] The present invention is further analyzed and described in conjunction with the embodiments and comparative examples, but the present invention is not limited to the description of the embodiments.

[0031] Example 1

[0032] 200 mg of a platinum-carbon catalyst (platinum loading 50%, brand TKK, model TEC10E40E) was weighed and placed in a 50 ml beaker A. 10 g of deionized water was added to completely wet the catalyst. 400 mg of a 5% mass concentration of Nafion solution (perfluorosulfonic acid polymer solution, brand DuPont, model D520) and 70 g of n-propyl alcohol were weighed and placed in beaker B. Beaker B was subjected to constant temperature ultrasonication for 5 minutes to uniform dispersion. The solution in beaker B was then transferred to beaker A. Beaker B was then washed with 7 g of deionized water. The washed deionized water was then transferred to beaker A again, and the solution solid content was adjusted to 0.05%. Finally, beaker A was subjected to constant temperature ultrasonication for 30 minutes in a constant temperature ultrasonication apparatus. The mixture was then sheared for 40 minutes under a nitrogen atmosphere using an IKA T25 device at a high speed of 5000 rpm. The mixture was then vacuum sheared for 5 minutes to obtain a uniformly mixed cathode and anode catalyst layer slurry.

[0033] The above-mentioned evenly dispersed cathode and anode catalyst layer slurry was sprayed on one side of the proton exchange membrane M765.08 using ultrasonic spraying equipment to form the anode catalyst layer. Sprayed onto a 400-mesh stainless steel wire mesh, a 1mm thick PTFE membrane was used as the base membrane to form the cathode catalyst layer, and dried on a vacuum platform at 75°C. The platinum loading of the catalyst layer was calculated and controlled by the platinum content of the catalyst layer slurry, and the platinum loading in the catalyst layer was verified by weighing. The anode platinum loading was 0.04mg / cm 2 , the cathode platinum loading is 0.2 mg / cm 2 .

[0034] The cathode catalyst layer is attached to the effective area of ​​the unsprayed side of the proton exchange membrane with the PTFE membrane facing outward, and placed between the parallel 3-wire hot press platens at 120°C for 240 seconds. Then, it is taken out and naturally cooled to tear off the PTFE membrane to form the anode and cathode catalyst layers on both sides of the proton membrane.

[0035] Finally, place the membrane electrode with diffusion layers on both sides between parallel 3-wire pressing plates and hot press at 100℃ for 240s, then take it out and cool it naturally.

[0036] Example 2

[0037] 1 g of a platinum-carbon catalyst (50% platinum loading, brand TKK, model TEC10E60TPM) was weighed and placed in a 50 ml beaker A. 10 g of deionized water was added to completely wet the catalyst. 20 g of a 5% mass concentration of Nafion solution (brand DuPont, model D520) and 6 g of n-propyl alcohol were weighed and placed in beaker B. Beaker B was placed in a constant temperature ultrasonicator and subjected to constant temperature ultrasonication for 5 minutes to uniform dispersion. The solution in beaker B was then transferred to beaker A. Beaker B was then washed with 30 g of deionized water, and the washed deionized water was transferred back to beaker A to adjust the solution solids content to 5%. Finally, beaker A was placed in a constant temperature ultrasonicator and subjected to constant temperature ultrasonication for 30 minutes. The mixture was then sheared using an IKA T25 apparatus at a high speed of 15,000 rpm under a nitrogen atmosphere for 40 minutes, and then vacuum sheared for 5 minutes to obtain a uniformly mixed anode and cathode catalyst layer slurry.

[0038] The above-mentioned evenly dispersed cathode and anode catalyst layer slurry was sprayed on one side of the proton exchange membrane M765.08 using ultrasonic spraying equipment to form the anode catalyst layer. Sprayed onto a 1000-mesh stainless steel wire mesh, a 0.1mm thick PTFE membrane was used as the base membrane to form the cathode catalyst layer, and dried on a vacuum platform at 75°C. The platinum loading of the catalyst layer was controlled by calculating the platinum content of the catalyst layer slurry, and the platinum loading in the catalyst layer was verified by weighing. The anode platinum loading was 0.04mg / cm 2 , the cathode platinum loading is 0.35 mg / cm 2 .

[0039] The cathode catalyst layer is attached to the effective area of ​​the unsprayed side of the proton exchange membrane with the PTFE membrane facing outward, and placed between the parallel 3-wire hot press platens at 120°C for 240 seconds. Then, it is taken out and naturally cooled to tear off the PTFE membrane to form the anode and cathode catalyst layers on both sides of the proton membrane.

[0040] Finally, place the membrane electrode with diffusion layers on both sides between parallel 3-wire pressing plates and hot press at 100℃ for 240s, then take it out and cool it naturally.

[0041] Example 3

[0042] 0.5 g of a platinum-carbon catalyst (platinum loading 50%, brand TKK, model TEC10E50E) was weighed and placed in a 50 ml beaker A. 10 g of deionized water was added to completely wet the catalyst. 5 g of a 5% mass concentration of Nafion solution (brand DuPont, model D520) and 15 g of n-propyl alcohol were weighed and placed in beaker B. Beaker B was placed in a thermosonicator and subjected to constant temperature ultrasound for 5 minutes to uniform dispersion. The solution in beaker B was then transferred to beaker A. Beaker B was then washed with 10 g of deionized water, and the washed deionized water was transferred back to beaker A to adjust the solution solids content to 2.5%. Finally, beaker A was placed in a thermosonicator and subjected to constant temperature ultrasound for 30 minutes. The mixture was then sheared for 40 minutes using an IKAT25 device at a high speed of 10,000 rpm under a nitrogen atmosphere. The mixture was then vacuum sheared for 5 minutes to obtain a uniformly mixed cathode and anode catalyst layer slurry.

[0043] The above-mentioned evenly dispersed cathode and anode catalyst layer slurry was sprayed on one side of the proton exchange membrane M765.08 using ultrasonic spraying equipment to form the anode catalyst layer. Sprayed onto a 700-mesh titanium wire mesh, a 0.5mm thick PTFE membrane was used as the base membrane to form the cathode catalyst layer, and dried on a vacuum platform at 75°C. The platinum loading of the catalyst layer was controlled by calculating the platinum content of the catalyst layer slurry, and the platinum loading in the catalyst layer was verified by weighing. The loading of the anode platinum was 0.04mg / cm 2 , the cathode platinum loading is 0.35 mg / cm 2 .

[0044] The cathode catalyst layer is attached to the effective area of ​​the unsprayed side of the proton exchange membrane with the PTFE membrane facing outward, and placed between the parallel 3-wire hot press platens at 120°C for 240 seconds. Then, it is taken out and naturally cooled to tear off the PTFE membrane to form the anode and cathode catalyst layers on both sides of the proton membrane.

[0045] Finally, place the membrane electrode with diffusion layers on both sides between parallel 3-wire pressing plates and hot press at 100℃ for 240s, then take it out and cool it naturally.

[0046] Comparative Example 1

[0047] 200 mg of a platinum-carbon catalyst (platinum loading 50%, brand TKK, model TEC10E40E) was weighed and placed in a 50 ml beaker A. 10 g of deionized water was added to completely wet the catalyst. 400 mg of a 5% mass concentration of Nafion solution (brand DuPont, model D520) and 70 g of n-propyl alcohol were weighed and placed in beaker B. Beaker B was placed in a thermosonicator and subjected to constant temperature ultrasound for 5 minutes to uniform dispersion. The solution in beaker B was then transferred to beaker A. Beaker B was then washed with 7 g of deionized water, and the washed deionized water was transferred back to beaker A. The solid content of the solution was adjusted to 0.05%. Finally, beaker A was placed in a thermosonicator and subjected to constant temperature ultrasound for 30 minutes. The mixture was then sheared for 40 minutes using an IKA T25 device at a high speed of 5000 rpm under a nitrogen atmosphere. The mixture was then vacuum sheared for 5 minutes to obtain a uniformly mixed cathode and anode catalyst layer slurry.

[0048] The above-mentioned evenly dispersed cathode and anode catalyst layer slurry was sprayed on one side of the proton exchange membrane M765.08 using ultrasonic spraying equipment to form the anode catalyst layer. The cathode catalyst layer was sprayed onto a 1mm thick PTFE membrane as the base membrane and dried on a vacuum platform at 75°C. The platinum loading of the catalyst layer was calculated and controlled by the platinum content of the catalyst layer slurry, and the platinum loading in the catalyst layer was verified by weighing. The anode platinum loading was 0.04mg / cm 2 , the cathode platinum loading is 0.35 mg / cm 2 .

[0049] The cathode catalyst layer is attached to the effective area of ​​the unsprayed side of the proton exchange membrane with the PTFE membrane facing outward, and placed between the parallel 3-wire hot press platens at 120°C for 240 seconds. Then, it is taken out and naturally cooled to tear off the PTFE membrane to form the anode and cathode catalyst layers on both sides of the proton membrane.

[0050] Finally, place the membrane electrode with diffusion layers on both sides between parallel 3-wire pressing plates and hot press at 100℃ for 240s, then take it out and cool it naturally.

[0051] Comparative Example 2

[0052] 1 g of a platinum-carbon catalyst (50% platinum loading, brand TKK, model TEC10E60TPM) was weighed and placed in a 50 ml beaker A. 10 g of deionized water was added to completely wet the catalyst. 20 g of a 5% mass concentration of Nafion solution (brand DuPont, model D520) and 6 g of n-propyl alcohol were weighed and placed in beaker B. Beaker B was placed in a constant temperature ultrasonicator and subjected to constant temperature ultrasonication for 5 minutes to uniform dispersion. The solution in beaker B was then transferred to beaker A. Beaker B was then washed with 30 g of deionized water, and the washed deionized water was transferred back to beaker A to adjust the solution solids content to 5%. Finally, beaker A was placed in a constant temperature ultrasonicator and subjected to constant temperature ultrasonication for 30 minutes. The mixture was then sheared using an IKA T25 apparatus at a high speed of 15,000 rpm under a nitrogen atmosphere for 40 minutes, and then vacuum sheared for 5 minutes to obtain a uniformly mixed anode and cathode catalyst layer slurry.

[0053] The above-mentioned evenly dispersed cathode and anode catalyst layer slurry was sprayed on one side of the proton exchange membrane M765.08 using ultrasonic spraying equipment to form the anode catalyst layer. The cathode catalyst layer was sprayed onto a 0.1mm thick PTFE membrane as the base membrane and dried on a vacuum platform at 75°C. The platinum loading of the catalyst layer was calculated and controlled by the platinum content of the catalyst layer slurry, and the platinum loading in the catalyst layer was verified by weighing. The anode platinum loading was 0.04mg / cm 2 , the cathode platinum loading is 0.35 mg / cm 2 .

[0054] The cathode catalyst layer is attached to the effective area of ​​the unsprayed side of the proton exchange membrane with the PTFE membrane facing outward, and placed between the parallel 3-wire hot press platens at 120°C for 240 seconds. Then, it is taken out and naturally cooled to tear off the PTFE membrane to form the anode and cathode catalyst layers on both sides of the proton membrane.

[0055] Finally, place the membrane electrode with diffusion layers on both sides between parallel 3-wire pressing plates and hot press at 100℃ for 240s, then take it out and cool it naturally.

[0056] Comparative Example 3

[0057] 0.5 g of a platinum-carbon catalyst (platinum loading 50%, brand TKK, model TEC10E50E) was weighed and placed in a 50 ml beaker A. 10 g of deionized water was added to completely wet the catalyst. 5 g of a 5% mass concentration of Nafion solution (brand DuPont, model D520) and 15 g of n-propyl alcohol were weighed and placed in beaker B. Beaker B was placed in a thermosonicator and subjected to constant temperature ultrasound for 5 minutes to uniform dispersion. The solution in beaker B was then transferred to beaker A. Beaker B was then washed with 10 g of deionized water, and the washed deionized water was transferred back to beaker A to adjust the solution solids content to 2.5%. Finally, beaker A was placed in a thermosonicator and subjected to constant temperature ultrasound for 30 minutes. The mixture was then sheared for 40 minutes using an IKAT25 device at a high speed of 10,000 rpm under a nitrogen atmosphere. The mixture was then vacuum sheared for 5 minutes to obtain a uniformly mixed cathode and anode catalyst layer slurry.

[0058] The above-mentioned evenly dispersed cathode and anode catalyst layer slurry was sprayed on one side of the proton exchange membrane M765.08 using ultrasonic spraying equipment to form the anode catalyst layer. The cathode catalyst layer was sprayed onto a 0.5mm thick PTFE membrane as the base membrane and dried on a vacuum platform at 75°C. The platinum loading of the catalyst layer was calculated and controlled by the platinum content of the catalyst layer slurry, and the platinum loading in the catalyst layer was verified by weighing. The anode platinum loading was 0.04mg / cm 2 , the cathode platinum loading is 0.35 mg / cm 2 .

[0059] The cathode catalyst layer is attached to the effective area of ​​the unsprayed side of the proton exchange membrane with the PTFE membrane facing outward, and placed between the parallel 3-wire hot press platens at 120°C for 240 seconds. Then, it is taken out and naturally cooled to tear off the PTFE membrane to form the anode and cathode catalyst layers on both sides of the proton membrane.

[0060] Finally, place the membrane electrode with diffusion layers on both sides between parallel 3-wire pressing plates and hot press at 100℃ for 240s, then take it out and cool it naturally.

[0061] The fuel cell membrane electrodes prepared in Examples 1-3 and Comparative Examples 1-3 were assembled into fuel cells 25 cm in diameter according to Part 5 of GB-T 2004 2.5-2009 Proton Exchange Membrane Fuel Cells. 2 Single battery, IV curve test is carried out under national standard test conditions. The test results are as follows Figure 1 As shown in the figure, it can be seen that the performance of the membrane electrode prepared by the method of the present invention is significantly improved compared with the membrane electrode prepared by conventional methods. The electrical performance is at the same level and the curves are relatively overlapped at the low current density stage. 2There is a significant difference in the improvement of current density, indicating that the metal wire mesh and the matching preparation method have a significant optimization effect on the ohmic polarization and mass transfer polarization of the membrane electrode. From a single example and comparative example, it can be seen that the metal wire mesh as an obvious variable has a significant effect on improving the electrical performance of the membrane electrode.

Claims

1. A membrane electrode for a fuel cell, comprising a proton exchange membrane and a cathode catalyst layer and an anode catalyst layer located on both sides of the proton exchange membrane, characterized in that: The cathode catalyst layer comprises a metal mesh with a bottom film attached thereto, and the catalyst is coated on the metal mesh; The wire mesh has a wire diameter of 10-30 μm and a pore size of 10-33 μm; The catalyst in the cathode catalyst layer is covered on the metal mesh, and the catalyst particles with a particle size smaller than the metal mesh aperture penetrate into the space between the base membrane and the metal mesh, and the particles with a particle size larger than the metal mesh aperture cover the surface of the metal mesh, forming a cathode catalyst layer with a gradient structure.

2. The membrane electrode for fuel cell according to claim 1, wherein The metal wire mesh is a stainless steel wire mesh or a titanium wire mesh.

3. The membrane electrode for fuel cell according to claim 1, wherein The bottom membrane is a PTFE membrane with a thickness of 0.1-1 mm.

4. The membrane electrode for fuel cell according to claim 1, wherein The cathode and anode catalyst layers respectively include a catalyst and an ion exchange resin, wherein the catalyst is a ternary platinum alloy catalyst, and the mass ratio of the catalyst to the ion exchange resin is 1-10:1; the ion exchange resin is one of DuPont D520, DuPont D2020, Solvay D83 and D79.

5. The membrane electrode for fuel cell according to claim 4, wherein: The catalyst is a platinum-carbon catalyst or a platinum-cobalt-carbon catalyst, and the platinum mass content of the catalyst is 40%-60%; the platinum loading of the cathode catalyst layer is 0.1-0.35 mg / cm 2 The platinum loading of the anode catalyst layer is 0.04-0.06 mg / cm 2 .

6. The method for preparing a membrane electrode for a fuel cell according to any one of claims 1 to 5, wherein: The following steps are involved: (1) After mixing an organic solvent and an ion exchange resin, a catalyst is added to obtain a cathode catalyst slurry and an anode catalyst slurry; (2) The cathode catalyst slurry obtained in step (1) is first coated on a metal wire mesh with a base film, and then thermally transferred to one side of the proton exchange membrane; the anode catalyst slurry is coated on the other side of the proton exchange membrane, thereby obtaining a membrane electrode for a fuel cell; The organic solvent in step (1) is at least one of ethanol, n-propanol, isopropanol and n-butanol, and the catalyst is a ternary platinum alloy catalyst.

7. The preparation method according to claim 6, wherein The specific steps of step (1) are: (I) mixing an organic solvent, water and an ion exchange resin to obtain a mixed solution; (II) mixing the mixed solution in (I) and a catalyst to obtain cathode and anode catalyst slurries; The mass ratio of the organic solvent to water in step (I) is 1:0.1-5, and the solid content of the mixed solution in step (II) is 0.5%-5%.

8. The preparation method according to claim 7, wherein The particle size of the cathode and anode catalyst slurries is 0.5-50 μm; the ternary platinum alloy catalyst is TKK brand TEC10E40E, TEC10E60TPM or TEC10E50E, and the platinum mass content is 50%.

9. The preparation method according to claim 6, wherein The coating treatment conditions in step (2) are: heating plate 75-90°C, slurry spraying flow rate 0.5-7.2 ml / min, nozzle height 20-50 mm, nozzle moving speed 80-500 mm / min, spraying operation is performed with a spraying interval of 5-10 mm, adjacent spraying trajectories are set to overlap by 5%-15%, and the spraying direction is perpendicular to the gas flow direction of the bipolar plate.

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