A method for preparing a high-uniformity fuel cell membrane electrode

Abstract

The present invention discloses a method for preparing a high-uniformity fuel cell membrane electrode, comprising the following steps: step a. preparing CCM by ultrasonic spraying, step b. preparing a diffusion layer by screen printing, and step c. assembling the membrane electrode. The beneficial effect of the present invention is that a heating plate is provided at the bottom of the spraying jig, the surface of the heating plate is provided with a circular through-hole, and the bottom of the heating plate is provided with an exhaust device. By optimizing the temperature of the heating plate, the solvent in the catalytic layer can be volatilized in time and pores can be formed; by adjusting the spray carrier gas pressure and the exhaust pressure of the heating plate, the pressure difference is ensured to be 0.1KPa-5KPa, thereby forming a downward flow field, which can limit the spraying range and ensure spraying uniformity.

Description

Technical Field

[0001] The present invention relates to the field of preparation of fuel cell membrane electrodes, in particular to a method for preparing a fuel cell membrane electrode with high uniformity. Background Art

[0002] The membrane electrode assembly (MEA) is the site where the electrochemical redox reaction occurs in fuel cells, primarily converting chemical energy into electrical energy. The MEA consists of a proton exchange membrane (PEM) and two layers, the catalyst layer (CL) and diffusion layer (GDL), on either side of the membrane. The quality of the MEA determines the performance, lifespan, and cost of the fuel cell, with the preparation of the catalyst coating membrane (CCM) being a key production step. Therefore, how to produce MEAs with excellent electrochemical performance remains a technical challenge for those skilled in the art. Currently, the main CCM preparation processes include hot pressing, sputtering, and ultrasonic spraying. Ultrasonic spraying utilizes ultrasound to atomize the catalyst slurry into fine droplets, which are then sprayed onto the PEM under the influence of an airflow. Compared to other coating methods, ultrasonic spraying offers a simple process, produces thinner, more uniform coatings, and facilitates self-humidification in fuel cells, reduces costs, and improves discharge performance. However, during the ultrasonic spraying process, MEA preparation can present challenges such as PEM swelling, delayed catalyst drying, uneven spraying, and catalyst agglomeration, significantly impacting the overall performance of the MEA.

[0003] The present invention uses ultrasonic spraying to prepare the CCM and screen printing to prepare the diffusion layer. Finally, the components are assembled and hot-pressed to produce the MEA. By installing a heating plate and optimizing the spraying process, spraying efficiency is improved while significantly reducing slurry loss, maximizing Pt utilization and achieving a uniform catalyst layer thickness. Furthermore, by optimizing the screen printing process, the resulting diffusion layer exhibits high flatness and excellent conductivity.

[0004] Patent application number 202011453018.9 discloses a method for preparing a fuel cell membrane electrode, including the preparation of a catalyst slurry, spraying a CCM-structured membrane electrode, and hot-pressing the membrane electrode package. This invention can avoid the deformation and distortion of the PEM during the spraying and hot-pressing process, but the process is cumbersome, requiring spraying a catalytic layer on one side of the PEM, followed by hot-pressing, and then repeating the above steps on the other side. Furthermore, the PEM needs to be glued to the support membrane, which takes a long time to prepare and is not conducive to mass production. Summary of the Invention

[0005] The purpose of the present invention is to solve the above problems and to design a method for preparing a fuel cell membrane electrode with high uniformity.

[0006] The technical solution of the present invention to achieve the above-mentioned purpose is a method for preparing a high-uniformity fuel cell membrane electrode, comprising the following steps:

[0007] Step a. preparing CCM by ultrasonic spraying;

[0008] The ultrasonic spraying method comprises the following steps:

[0009] Step S1: Flatten and fix the proton exchange membrane in a spraying jig, and set a heating plate at the bottom of the spraying jig. The surface of the heating plate is provided with a circular through hole, and the bottom of the heating plate is provided with an exhaust device to form a pressure gradient between the nozzle and the PEM. Then, the spraying jig assembly is placed in an ultrasonic spray machine.

[0010] Step S2: Setting the ultrasonic spraying machine parameters, spraying the homogenized catalyst slurry onto the PEM surface.

[0011] Step S3: After the spraying is completed and the catalyst layer is dried, the prepared CCM is removed from the mold and the subsequent packaging, pressing and other steps are carried out.

[0012] Step b. preparing the diffusion layer by screen printing;

[0013] The screen printing method comprises the following steps:

[0014] Step S1: mixing a conductive material, a dispersion liquid, a pore-forming agent, and a hydrophobic agent in a certain proportion and uniformly dispersing them to obtain a microporous layer slurry;

[0015] Step S2: immersing the carbon paper in a polytetrafluoroethylene (PTFE) solution of a certain concentration for hydrophobic treatment, and then placing the carbon paper in an oven for drying and high-temperature curing;

[0016] Step S3, setting the parameters of the screen printing machine, applying the microporous layer slurry on the hydrophobic treated carbon paper surface in batches by screen printing, vacuum drying and then baking;

[0017] Step S4: spraying a certain concentration of Nafion solution on the surface of the microporous layer and drying it at room temperature;

[0018] Step c. membrane electrode assembly;

[0019] The membrane electrode assembly comprises the following steps:

[0020] Step S1: Apply PI tape around the effective area of ​​the CCM and seal it with edge sealing material;

[0021] Step S2: After stacking and assembling the CCM, the sealing frame, and the diffusion layer, the two sides are clamped with thin metal plates, silicone pads, hard graphite plates, and paper shells in sequence, and then placed in a hydraulic press for hot pressing. After cooling, the MEA is obtained.

[0022] The proton exchange membrane is a perfluorosulfonic acid membrane with a thickness of 6 μm to 18 μm.

[0023] In the step a, when spraying the catalyst slurry, the atomized particle size can reach 2 nm to 10 nm by changing the atomization power;

[0024] In step a, during spraying, the nozzle height is 60 mm to 120 mm;

[0025] In step a, during spraying, the nozzle carrier gas pressure is 1 kPa to 20 kPa;

[0026] In step a, during spraying, the temperature of the heating plate is 90°C to 130°C;

[0027] In step a, a vacuum device is provided at the bottom of the heating plate, and the vacuum rate is controlled to form a pressure gradient of 0.1 kPa-5 kPa between the nozzle and the PEM;

[0028] In step a, the diameter of the circular through holes on the surface of the heating plate is 0.5 mm to 5 mm, and the distance between the two holes is 3 mm to 20 mm;

[0029] In step a, during spraying, the spraying path of the nozzle is to spray in a 'Z' shape along the short side of the PEM;

[0030] In step a, during spraying, the feed speed is 20 mm to 60 mm / s;

[0031] In step a, during spraying, the slurry flow rate is 0.1 mL / min to 1.0 mL / min;

[0032] In step a, during spraying, the spraying time is 5 min to 25 min;

[0033] In step a, the catalyst loading on the anode side of the CCM is 0.1 mg / cm 2 ~0.3 mg / cm 2 ; The catalyst loading on the cathode side is 0.2 mg / cm 2 ~0.6 mg / cm 2 .

[0034] The catalyst utilization rate is 85% to 95%.

[0035] The thickness of the catalytic layer is 8.5 μm±1.5 μm.

[0036] In the step b, the mass fraction of the polytetrafluoroethylene solution is 10% to 60%;

[0037] In step b, the heat treatment temperature is 140°C to 350°C;

[0038] In step b, the heat treatment time is 10 min to 60 min.

[0039] The thickness of the microporous layer is 30 μm±5 μm.

[0040] The thickness of the edge sealing material is 40 μm to 130 μm;

[0041] In step c, during pressing, the pressing temperature is 90° C. to 130° C.;

[0042] In step c, during pressing, the pressing time is 60 s to 200 s.

[0043] A method for preparing a highly uniform fuel cell membrane electrode using the technical solution of the present invention comprises a heating plate disposed beneath a spraying fixture, the surface of which is provided with circular through-holes, and an exhaust device disposed beneath the heating plate. By optimizing the heating plate temperature, the solvent in the catalyst layer can be readily evaporated and pores can be formed. By adjusting the spray carrier gas pressure and the exhaust pressure of the heating plate to maintain a pressure differential between 0.1 kPa and 5 kPa, a downward flow field is formed, which limits the spraying range and ensures spray uniformity.

[0044] The present invention adopts ultrasonic spraying method, and by optimizing parameters such as atomization power, spray flow rate, and working speed, the spraying efficiency is greatly improved and it is conducive to the uniform dispersion of the platinum catalyst. The thickness of the prepared CCM catalytic layer is uniform, with a total thickness between 36.5μm±1.5μm.

[0045] By optimizing parameters such as nozzle height and spraying path, the slurry spraying outside the effective adhesion area is reduced, the slurry loss rate during the spraying process is reduced, the utilization rate of precious metal platinum is maximized, the cost of catalyst raw materials is saved, and the catalyst slurry utilization rate is as high as 85%-95%.

[0046] The present invention prepares the diffusion layer by screen printing. By performing screen printing in batches, optimizing the screen printing interval time and the carbon loading of the microporous layer, a diffusion layer with excellent surface flatness is prepared, which is conducive to sufficient contact with the CCM during the pressing process and reduces the internal resistance of the battery. In addition, the above-mentioned diffusion layer has good conductivity and gas permeability, which greatly improves the overall performance of the membrane electrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 This is a schematic diagram of the MEA structure of this patent.

[0048] Figure 2 This is the thickness distribution diagram of the CCM prepared by this patent.

[0049] Figure 3 1 and 2 are the MEA polarization curves of Examples 1 and 4. Implementation Method

[0050] The present invention will be described in detail below with reference to the accompanying drawings. Figure 1-3 As shown, a method for preparing a high-uniformity fuel cell membrane electrode comprises the following steps:

[0051] Step a. preparing CCM by ultrasonic spraying;

[0052] The ultrasonic spraying method comprises the following steps:

[0053] Step S1: Flatten and fix the proton exchange membrane in a spraying jig, and set a heating plate at the bottom of the spraying jig. The surface of the heating plate is provided with a circular through hole, and the bottom of the heating plate is provided with an exhaust device to form a pressure gradient between the nozzle and the PEM. Then, the spraying jig assembly is placed in an ultrasonic spray machine.

[0054] Step S2: setting the ultrasonic spraying machine parameters to spray the homogenized catalyst slurry onto the PEM surface;

[0055] Step S3: After the spraying is completed and the catalytic layer is dried, the prepared CCM is removed from the mold and subsequent packaging, pressing and other steps are performed.

[0056] Step b. preparing the diffusion layer by screen printing;

[0057] The screen printing method comprises the following steps:

[0058] Step S1: mixing a conductive material, a dispersion liquid, a pore-forming agent, and a hydrophobic agent in a certain proportion and uniformly dispersing them to obtain a microporous layer slurry;

[0059] Step S2: immersing the carbon paper in a polytetrafluoroethylene (PTFE) solution of a certain concentration for hydrophobic treatment, and then placing the carbon paper in an oven for drying and high-temperature curing;

[0060] Step S3, setting the parameters of the screen printing machine, applying the microporous layer slurry on the hydrophobic treated carbon paper surface in batches by screen printing, vacuum drying and then baking;

[0061] Step S4: spraying a certain concentration of Nafion solution on the surface of the microporous layer and drying it at room temperature;

[0062] Step c. membrane electrode assembly;

[0063] The membrane electrode assembly comprises the following steps:

[0064] Step S1: Apply PI tape around the effective area of ​​the CCM and seal it with edge sealing material;

[0065] Step S2: After stacking and assembling the CCM, the sealing frame, and the diffusion layer, the two sides are clamped with thin metal plates, silicone pads, hard graphite plates, and paper shells in sequence, and then placed in a hydraulic press for hot pressing. After cooling, the MEA is obtained;

[0066] As a preferred technical solution, further, the proton exchange membrane is a perfluorosulfonic acid membrane with a thickness of 6 μm to 18 μm.

[0067] As a preferred technical solution, further, in the step a, when spraying the catalyst slurry, the atomized particle size can reach 2 nm to 10 nm by changing the atomization power;

[0068] In step a, during spraying, the nozzle height is 60 mm to 120 mm;

[0069] In step a, during spraying, the nozzle carrier gas pressure is 1 kPa to 20 kPa;

[0070] In step a, during spraying, the temperature of the heating plate is 90°C to 130°C;

[0071] In step a, a vacuum device is provided at the bottom of the heating plate, and the vacuum rate is controlled to form a pressure gradient of 0.1 kPa-5 kPa between the nozzle and the PEM;

[0072] In step a, the diameter of the circular through holes on the surface of the heating plate is 0.5 mm to 5 mm, and the distance between the two holes is 3 mm to 20 mm;

[0073] In step a, during spraying, the spraying path of the nozzle is to spray in a 'Z' shape along the short side of the PEM;

[0074] In step a, during spraying, the feed speed is 20 mm / s to 60 mm / s;

[0075] In step a, during spraying, the slurry flow rate is 0.1 mL / min to 1.0 mL / min;

[0076] In step a, during spraying, the spraying time is 5 min to 25 min;

[0077] In step a, the catalyst loading on the anode side of the CCM is 0.1 mg / cm 2 ~0.3 mg / cm 2 ; The catalyst loading on the cathode side is 0.2 mg / cm 2 ~0.6 mg / cm 2 .

[0078] As a preferred technical solution, further, the catalyst utilization rate is 85% to 95%.

[0079] As a preferred technical solution, further, the thickness of the catalytic layer is 8.5 μm±1.5 μm.

[0080] As a preferred technical solution, further, in step b, the mass fraction of the polytetrafluoroethylene solution is 10% to 60%;

[0081] In step b, the heat treatment temperature is 140°C to 350°C;

[0082] In step b, the heat treatment time is 10 min to 60 min.

[0083] As a preferred technical solution, further, the thickness of the microporous layer is 30 μm±5 μm.

[0084] As a preferred technical solution, further, the thickness of the edge sealing material is 40 μm to 130 μm;

[0085] In step c, during pressing, the pressing temperature is 90° C. to 130° C.;

[0086] In step c, during pressing, the pressing time is 60 s to 200 s.

[0087] In this embodiment, Example

[0088] Membrane electrode assembly:

[0089] Step 1

[0090] Preparation of CCM by ultrasonic spraying:

[0091] 1. Clean, reset, and preheat the spray machine, then place the spray fixture assembly into the ultrasonic spray machine.

[0092] 2. Set the ultrasonic spraying parameters: hot plate temperature 130°C, spray height 100 cm, nozzle carrier gas pressure 5 kPa, atomization power 2.0 W, feed speed 22 mm / s, slurry flow rate 0.40 mL / min, spray time 20 min, spray path is a 'Z' shape along the long side of the PEM, and the pressure gradient between the nozzle and the PEM is 2 kPa. Then spray the homogenized catalyst slurry onto the PEM surface so that the catalyst loading on the anode side of the membrane electrode is 0.2 mg / cm 2 The catalyst loading on the cathode side is 0.4 mg / cm 2 . Spray one side first, then turn it over and spray the other side.

[0093] 3. After the spraying is completed and the catalyst layer is dried, the prepared CCM is removed from the mold and proceeds to subsequent packaging, pressing and other steps.

[0094] Step 2

[0095] Preparation of diffusion layer by screen printing:

[0096] 1. Weigh 3.2 g of carbon powder and add 190 mL of isopropanol and 2 mL of ethylene glycol to it. Homogenize at high speed for 4 minutes. Then add 60 mL of 0.45 mol / L ammonium oxalate solution and homogenize for 2 minutes. Finally, add 10.8 mL of 20% PTFE and ultrasonicate for 2 minutes to obtain a microporous layer slurry. Store in a refrigerator at 4°C.

[0097] 2. Immerse TGP-H-060 carbon paper in 7% PTFE dilution for 15 seconds, then drain naturally and dry the carbon paper in an oven at 220°C for 20 minutes. Finally, calcinate the carbon paper in an oven at 345°C for 40 minutes to obtain hydrophobic carbon paper.

[0098] 3. Set the parameters of the screen printer, then fix the carbon paper prepared in step 2 on the area of ​​the air-intake plate, and evenly apply the microporous layer slurry prepared in step 1 on the surface of the hydrophobic treated carbon paper by screen printing. Screen printing is done once for the first time, followed by 2 times, 2 times, and 2 times, with an interval of 30 seconds between each screen printing. Then, place the screen-printed carbon paper in an oven at 140°C to dry, take it out and weigh it. If the increment of the microporous layer slurry does not reach the set value (1 mg / cm 2 ), repeat the above screen printing steps until the increment of the microporous layer slurry reaches the set value.

[0099] 4. Spray 0.5% Nafion solution on the surface of the microporous layer and dry it at room temperature to obtain a gas diffusion layer.

[0100] Step 3

[0101] Preparation of membrane electrode assembly:

[0102] 1. In the CCM effective area (280 cm 2 ) and apply 4 mm wide and 0.055 μm thick PI tape around the periphery and seal it with edge sealing material.

[0103] 2. Press CCM, edge sealing material and diffusion layer together. Figure 1 The two sides are stacked and assembled, and clamped with thin metal plates, silicone pads, hard graphite plates, and paper shells in turn, and then placed in a hydraulic press for hot pressing.

[0104] 3. Set the hot pressing temperature to 120°C, the pressure to 2.8 MPa, and the holding time to 90 s. After the membrane electrode assembly cools down, the membrane electrode assembly pressing process is completed.

[0105] Step 4

[0106] Testing membrane electrode performance:

[0107] The prepared membrane electrode assembly was tested, and the polarization curve was as follows Figure 3Test conditions: battery temperature 78°C, gas excess coefficient H2 / Air = 2 / 1.65, humidity 40%, no back pressure. Example

[0108] Step 1

[0109] Preparation of CCM by ultrasonic spraying:

[0110] 1. Clean, reset, and preheat the spray machine, then place the spray fixture assembly into the ultrasonic spray machine.

[0111] 2. Set the ultrasonic spraying machine parameters: hot plate temperature 110 ° C, spraying height 80 cm, carrier gas pressure 0.01 MPa, atomization power 2.5 W, working speed 40 mm / s, slurry flow rate 0.65 mL / min, spraying time 12 min, spraying path is a 'Z' shape along the short side of the PEM, and the pressure gradient between the nozzle and the PEM is 4 kPa. Then spray the homogenized catalyst slurry onto the PEM surface so that the catalyst loading on the anode side of the membrane electrode is 0.2 mg / cm 2 The catalyst loading on the cathode side is 0.4 mg / cm 2 . Spray one side first, then turn it over and spray the other side.

[0112] 3. After the spraying is completed and the catalyst layer is dried, the prepared CCM is removed from the mold and proceeds to subsequent packaging, pressing and other steps.

[0113] Other steps are the same as in Example 1. Example

[0114] Step 1 is the same as Step 1 in Example 2.

[0115] Step 2

[0116] Preparation of diffusion layer by screen printing:

[0117] 1. Weigh 3.2 g of carbon powder and add 190 mL of isopropanol and 2 mL of ethylene glycol to it. Homogenize at high speed for 4 minutes. Then add 60 mL of 0.45 mol / L ammonium oxalate solution and homogenize for 2 minutes. Finally, add 10.8 mL of 20% PTFE and ultrasonicate for 2 minutes to obtain a microporous layer slurry. Store in a refrigerator at 4°C.

[0118] 2. Immerse TGP-H-060 carbon paper in 7% PTFE dilution for 15 seconds, then drain naturally and dry the carbon paper in an oven at 220°C for 20 minutes. Finally, calcinate the carbon paper in an oven at 345°C for 40 minutes to obtain hydrophobic carbon paper.

[0119] 3. Set the parameters of the screen printer, then fix the carbon paper prepared in step 2 on the area of ​​the air-intake plate, and evenly apply the microporous layer slurry prepared in step 1 on the surface of the hydrophobic treated carbon paper by screen printing. Screen printing is done once for the first time, followed by 2 times, 2 times, and 2 times. The interval between each screen printing is 60 seconds. Then, the screen-printed carbon paper is placed in an oven at 140°C to dry, and weighed. If the increment of the microporous layer slurry does not reach the set value (1.5 mg / cm 2 ), repeat the above screen printing steps until the increment of the microporous layer slurry reaches the set value.

[0120] 4. Spray 0.5% Nafion solution on the surface of the microporous layer and dry it at room temperature to obtain a gas diffusion layer.

[0121] Other steps are the same as in Example 2. Example

[0122] Steps 1, 2, and 4 are the same as those in Example 3.

[0123] Step 3

[0124] Preparation of membrane electrode assembly:

[0125] 1. In the CCM effective area (280 cm 2 ) and apply 4 mm wide and 0.055 μm thick PI tape around the periphery and seal it with edge sealing material.

[0126] 2. Press CCM, edge sealing material and diffusion layer together. Figure 1 The two sides are stacked and assembled, and clamped with thin metal plates, silicone pads, hard graphite plates, and paper shells in turn, and then placed in a hydraulic press for hot pressing.

[0127] 3. Set the hydraulic press temperature to 100°C, gradually apply pressure after the upper pressure plate contacts the membrane electrode, and increase the pressure growth rate from 0.5 MPa / s to 2.8 MPa / s. The pressure is maintained for 90 s. After the membrane electrode assembly cools down, the membrane electrode assembly pressing process is completed.

[0128] As can be seen from Example 4, the membrane electrode assembly prepared in the embodiment of the present invention has a uniform thickness of the catalyst layer, a high flatness of the diffusion layer, and good air tightness of the MEA. 2 The voltage can reach 0.815 V at 800 mA / cm 2 The voltage can reach 0.729 V at 1600 mA / cm 2 The lower voltage can reach 0.620 V, and the single cell performance is excellent, which can reach the performance level of commercial membrane electrode.

[0129] The above technical solutions only reflect the preferred technical solutions of the technical solutions of the present invention. Any changes that may be made to certain parts thereof by those skilled in the art all reflect the principles of the present invention and fall within the scope of protection of the present invention.

Claims

1. A method for preparing a high uniformity fuel cell membrane electrode, characterized in that , including the following steps: Step a. preparing CCM by ultrasonic spraying; The ultrasonic spraying method comprises the following steps: Step S1: Flatten and fix the proton exchange membrane in a spraying jig, and set a heating plate at the bottom of the spraying jig. The surface of the heating plate is provided with a circular through hole, and the bottom of the heating plate is provided with an exhaust device to form a pressure gradient between the nozzle and the PEM. Then, the spraying jig assembly is placed in an ultrasonic sprayer. Step S2, setting the ultrasonic sprayer parameters of atomization power, nozzle height, feed speed, slurry flow rate, and spraying time, and spraying the homogenized catalyst slurry onto the PEM surface; During spraying, the nozzle uses carrier gas spraying with a carrier gas pressure of 1kPa-20 kPa; the nozzle spraying path is a 'Z'-shaped spray along the short side of the PEM, and by adjusting the spray carrier gas pressure and the exhaust rate of the heating plate, a pressure gradient of 2kPa-4kPa is formed between the nozzle and the PEM, thereby forming a downward flow field to limit the spraying range and ensure spraying uniformity; Step S3: After the spraying is completed and the catalyst layer is dried, the prepared CCM is removed from the mold and the subsequent packaging and pressing steps are performed; Step b. preparing the diffusion layer by screen printing; The screen printing method comprises the following steps: Step S1, mixing a conductive material, a dispersion liquid, a pore-forming agent, and a hydrophobic agent in a certain proportion and uniformly dispersing them to obtain a microporous layer slurry; Step S2: The carbon paper is immersed in a polytetrafluoroethylene (PTFE) solution of a certain concentration for hydrophobic treatment, and then placed in an oven for drying and high-temperature curing; Step S3, setting the parameters of the screen printing machine, applying the microporous layer slurry on the hydrophobic treated carbon paper surface in batches by screen printing, vacuum drying and then baking; Step S4, spraying a certain concentration of Nafion solution on the surface of the microporous layer and drying it at room temperature; Step c. membrane electrode assembly; The membrane electrode assembly comprises the following steps: Step S1, applying PI tape around the effective area of ​​the CCM and sealing it with edge sealing material; Step S2: After stacking and assembling the CCM, the sealing frame, and the diffusion layer, the two sides are clamped with thin metal plates, silicone pads, hard graphite plates, and paper shells in sequence, and then placed in a hydraulic press for hot pressing. After cooling, the MEA is obtained.

2. The method for preparing a high-uniformity fuel cell membrane electrode according to claim 1, characterized in that: The proton exchange membrane is a perfluorosulfonic acid membrane with a thickness of 6 μm-18 μm.

3. The method for preparing a high-uniformity fuel cell membrane electrode according to claim 1, characterized in that: In the step a, when spraying the catalyst slurry, the atomized particle size can reach 2 nm-10 nm by changing the atomization power; In step a, during spraying, the nozzle height is 60 mm to 120 mm; In step a, during spraying, the temperature of the heating plate is 90°C-130°C; In step a, the diameter of the circular through holes on the surface of the heating plate is 0.5 mm to 5 mm, and the distance between the two holes is 3 to 20 mm; In step a, during spraying, the feed speed is 20 mm / s-60 mm / s; In step a, during spraying, the slurry flow rate is 0.1 mL / min-1.0 mL / min; In step a, during spraying, the spraying time is 5 min-25 min; In step a, the catalyst loading on the anode side of the CCM is 0.1 mg / cm 2 -0.3 mg / cm 2 ; The catalyst loading on the cathode side is 0.2 mg / cm 2 -0.6 mg / cm 2 .

4. The method for preparing a high-uniformity fuel cell membrane electrode according to claim 1, characterized in that: The catalyst utilization rate is 85% to 95%.

5. The method for preparing a fuel cell membrane electrode with high uniformity according to claim 1, characterized in that: The thickness of the catalytic layer is 8.5 μm±1.5 μm.

6. The method for preparing a fuel cell membrane electrode with high uniformity according to claim 1, characterized in that: In the step b, the mass fraction of the polytetrafluoroethylene solution is 10% to 60%; In step b, the heat treatment temperature is 140°C to 350°C; In step b, the heat treatment time is 10 min to 60 min.

7. The method for preparing a high-uniformity fuel cell membrane electrode according to claim 1, characterized in that: The thickness of the microporous layer is 30 μm±5 μm.

8. The method for preparing a high-uniformity fuel cell membrane electrode according to claim 1, characterized in that: The thickness of the edge sealing material is 40 μm to 130 μm; In step c, during pressing, the pressing temperature is 90° C. to 130° C.; In step c, during pressing, the pressing time is 60 s to 200 s.

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