CN117594811B - Hot-pressing auxiliary reinforced fuel cell membrane electrode and preparation method thereof - Google Patents

Abstract

The invention discloses a hot-pressing auxiliary reinforced fuel cell membrane electrode and a preparation method thereof, belonging to the technical field of proton exchange membrane fuel cells. The membrane electrode comprises a proton exchange membrane, wherein both sides of the proton exchange membrane are respectively provided with a cathode catalytic layer and an anode catalytic layer, the outsides of the cathode catalytic layer and the anode catalytic layer are respectively provided with a gas diffusion layer, and the cathode catalytic layer and the anode catalytic layer comprise a platinum catalyst loaded by a carbon nano tube and perfluorinated sulfonic acid resin. The invention also provides a preparation method of the membrane electrode of the hot-pressing auxiliary enhanced fuel cell, which comprises the steps of loading the platinum carbon catalyst loaded by the carbon nano tube and the perfluorinated sulfonic acid resin on the proton exchange membrane through a spraying process to obtain a loose catalytic layer, and forming a denser conductive path between the layers of the loose carbon nano tube through a hot-pressing method, so that the stacking density of the catalyst in the catalytic layer is effectively improved, and the electrochemical performance of the membrane electrode is improved.

Description

A thermal pressure-assisted enhanced fuel cell membrane electrode and a preparation method thereof

Technical Field

The invention belongs to the technical field of proton exchange membrane fuel cells, and in particular relates to a thermal pressure-assisted enhanced fuel cell membrane electrode and a preparation method thereof.

Background Art

Proton exchange membrane fuel cell (PEMFC) is an advanced energy conversion technology that can directly convert chemical energy into electrical energy without going through the traditional combustion process. This type of battery has high efficiency energy conversion, zero emissions, and can be quickly started at a relatively low temperature, so it has broad application prospects in many fields. In proton exchange membrane fuel cells, the membrane electrode assembly (MEA) plays a key role, which directly affects the performance of the fuel cell. MEA includes a proton exchange membrane, anode and cathode catalyst layers, and gas diffusion layers located on the anode and cathode respectively. These components work together to affect the overall function of the membrane electrode.

The catalytic layer in the membrane electrode is generally composed of a catalyst and a resin, in which the catalyst plays the main electrocatalytic role, promoting the electrochemical reaction of hydrogen (at the anode) and oxygen (at the cathode). Platinum-carbon catalyst is a common type of catalyst, in which the carbon carrier plays a supporting and conductive role in the entire reaction process. The carbon carrier can be made of conductive carbon black, carbon fiber, carbon nanotubes and other materials. These carbon carriers have good electrical conductivity properties, which helps to transfer electrons to the catalyst, thereby promoting the electrochemical reaction of gas molecules.

Compared with conductive carbon black, carbon nanotubes show obvious advantages in conducting electrons. In addition, the chemical stability of carbon nanotubes also enables it to maintain excellent conductivity for a long time. The above advantages make carbon nanotube-loaded fuel cell catalysts have a wide range of application prospects. Patent document CN111244480B discloses a carbon-supported palladium-based alloy fuel cell membrane electrode and a preparation method thereof, using multi-walled carbon nanotubes or single-walled carbon nanotube carriers loaded with palladium-based alloys as the first catalytic layer, and multi-walled carbon nanotubes or single-walled carbon nanotube carriers loaded with platinum catalysts as the second catalytic layer, which are sprayed on the two surfaces of the proton exchange membrane to prepare the proton exchange membrane fuel cell membrane electrode. However, carbon nanotubes present a tubular structure and have a large specific surface area. Therefore, during the catalyst loading process, a relatively loose arrangement is usually formed, resulting in a low packing density. At this time, the carbon nanotubes between the layers cannot form an effective conductive path, so that the performance of the platinum-carbon catalyst loaded by the carbon nanotubes cannot be effectively exerted.

Summary of the invention

The purpose of the present invention is to provide a hot-pressing assisted enhanced fuel cell membrane electrode and a preparation method thereof, so as to solve the problem that the carbon nanotubes are loosely arranged, the stacking density is low, and an effective conductive path cannot be formed between the layers, resulting in poor electrochemical performance of the membrane electrode.

The purpose of the present invention can be achieved through the following technical solutions:

In a first aspect, a method for preparing a hot-pressing assisted enhanced fuel cell membrane electrode comprises the following steps:

S1. Preparation of catalyst layer slurry: Add water and isopropanol to the carbon nanotube-supported platinum catalyst (Pt/CNTs), stir at 30W ultrasonic power, then add perfluorosulfonic acid resin solution, mix evenly at room temperature (25-30°C), and obtain a uniformly dispersed ink-like catalyst slurry;

S2. Spraying: The proton exchange membrane is placed on a heating plate, and the catalyst layer slurry is sprayed on both sides of the proton exchange membrane in sequence to obtain a catalyst membrane having both an anode catalyst layer and a cathode catalyst layer;

S3. One-time hot pressing: firstly, PTFE (polytetrafluoroethylene) films are respectively attached to both sides of the catalyst membrane to obtain assembly a, then porous PTFE films are respectively attached to both sides of assembly a to obtain assembly b, and finally, thin copper sheets are respectively assembled on both sides of assembly b to support and protect it to obtain assembly c; assembly c is subjected to one-time hot pressing, and after the hot pressing is completed, the thin copper sheets, porous PTFE films and PTFE films on both sides are respectively peeled off to obtain a semi-finished hot pressing-assisted enhanced catalyst membrane;

S4. Secondary hot pressing: placing gas diffusion layers on both sides of the semi-finished hot pressing assisted enhanced catalytic membrane, and performing secondary hot pressing to obtain a fuel cell membrane electrode.

Furthermore, in S1, the stirring rate is 500 rpm and the stirring time is 30 min.

Furthermore, the mixing is performed by stirring in S1, the stirring rate is 10000 rpm, and the stirring time is 30 min.

Furthermore, the mass percentage of platinum in the carbon nanotube-supported platinum catalyst in S1 is 10%.

Furthermore, the mass percentage of the perfluorosulfonic acid resin solution in S1 is 20wt%.

Furthermore, the solvents of the catalyst slurry in S1 are water and isopropanol, and the volume ratio of water to isopropanol is 0.5-1.5:8.5-9.5.

Furthermore, the solute of the catalyst slurry in S1 is Pt/CNTs and perfluorosulfonic acid resin, and the mass percentage of the solute is 1-2%.

Furthermore, the mass ratio of the perfluorosulfonic acid resin in the solute to the carbon nanotubes in the Pt/CNTs is 0.7-0.8:1.

Furthermore, the total platinum loading of the anode catalyst layer and the cathode catalyst layer on both sides of the catalyst membrane in S2 is 0.5 mg/cm ² .

Furthermore, the ratio of platinum loadings of the anode catalyst layer and the cathode catalyst layer is 1:4, that is, the platinum loadings of the anode catalyst layer and the cathode catalyst layer on both sides of the catalyst membrane are 0.1 mg/cm ² and 0.4 mg/cm ² respectively.

Furthermore, the thickness of the proton exchange membrane in S2 is 12 μm.

Furthermore, the temperature of the heating plate in S2 is 90°C.

Furthermore, after the catalytic layer slurry in S2 is sprayed on one side of the proton exchange membrane, it is placed at 40°C for 1 hour to evaporate excess solvent to obtain a single-sided catalytic layer catalytic membrane, and then the catalytic layer slurry is sprayed on the other side of the proton exchange membrane and also placed at 40°C for 1 hour to obtain a catalytic membrane having both an anode catalytic layer and a cathode catalytic layer.

Furthermore, the thickness of the PTFE film in S3 is 0.4-0.8 mm, and the thickness of the copper sheet is 1 mm.

Furthermore, the porosity of the porous PTFE film in S3 is 20-40%.

Furthermore, the hot pressing conditions in S3 are hot pressing at 100-120° C. and 0.4-0.6 MPa for 80-120 seconds.

Furthermore, the thickness of the gas diffusion layer in S4 is 220 μm.

Furthermore, the secondary hot pressing condition in S4 is hot pressing at 140° C. and 3 MPa pressure for 120 s.

In a second aspect, the present invention provides a hot-pressing assisted enhanced fuel cell membrane electrode, wherein the hot-pressing assisted enhanced fuel cell membrane electrode is prepared by the hot-pressing assisted enhanced fuel cell membrane electrode preparation method described in the first aspect:

The thermal pressure-assisted enhanced fuel cell membrane electrode comprises a proton exchange membrane, a cathode catalyst layer is arranged on one side of the proton exchange membrane, an anode catalyst layer is arranged on the other side of the proton exchange membrane, and gas diffusion layers are arranged on the outer sides of the cathode catalyst layer and the anode catalyst layer; the cathode catalyst layer and the anode catalyst layer comprise a platinum catalyst supported by carbon nanotubes and a perfluorosulfonic acid resin.

Beneficial effects of the present invention:

The present invention provides a heat-pressing assisted enhanced fuel cell membrane electrode and a preparation method thereof, wherein a carbon nanotube-loaded platinum-carbon catalyst and a perfluorosulfonic acid resin are loaded on a proton exchange membrane through a spraying process to obtain a loose catalytic layer, and then a heat-pressing method is used to form a denser conductive path between the layers of the loose carbon nanotubes, thereby effectively increasing the stacking density of the catalyst in the catalytic layer, thereby improving the electrochemical performance of the membrane electrode.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be further described below in conjunction with the accompanying drawings.

FIG1 is a schematic diagram of the structure of a thermal pressure-assisted enhanced fuel cell membrane electrode according to the present invention;

FIG2 is a schematic diagram of polarization curves of Example 2 and Comparative Example 1 in Example 5 of the present invention;

FIG3 is a scanning electron microscope characterization image of Example 2 and Comparative Example 1 in Example 5 of the present invention;

In the figure: 1. Proton exchange membrane; 2. Cathode catalyst layer; 3. Anode catalyst layer; 4. Gas diffusion layer.

DETAILED DESCRIPTION

The following will be combined with 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 creative work are within the scope of protection of the present invention.

Example 1

Please refer to Figure 1, which shows a heat-pressing assisted enhanced fuel cell membrane electrode, wherein the heat-pressing assisted enhanced fuel cell membrane electrode includes a proton exchange membrane 1, a cathode catalyst layer 2 is arranged on one side of the proton exchange membrane 1, an anode catalyst layer 3 is arranged on the other side of the proton exchange membrane 1, and gas diffusion layers 4 are arranged on the outer sides of the cathode catalyst layer 2 and the anode catalyst layer 3.

Example 2

A method for preparing a hot-pressing assisted enhanced fuel cell membrane electrode comprises the following steps:

S1. Preparation of catalytic layer slurry: 5.25 mL of distilled water and 29.75 mL of isopropanol were added to 0.5 g of Pt/CNTs (the mass percentage of platinum was 10%), and the mixture was stirred at 500 rpm for 30 min in a 30 W ultrasonic cleaner. Then 1.0 g of perfluorosulfonic acid resin solution (the mass percentage was 20 wt%) was added, and the mixture was stirred at 10,000 rpm for 30 min at room temperature to obtain a uniformly dispersed ink-like catalyst slurry; the solvent of the catalyst slurry was water and isopropanol, and the volume ratio of water to isopropanol was 1.5:8.5; the solute was Pt/CNTs and perfluorosulfonic acid resin, and the mass percentage of the solute was 2%, and the mass ratio of perfluorosulfonic acid resin to carbon nanotubes in Pt/CNTs was 0.8:1.

S2. Spraying: Place a 12 μm thick proton exchange membrane on a heating plate at 90°C, pour the catalyst layer slurry into a spray gun and spray it on one side of the proton exchange membrane, then place it at 40°C for 1 hour to evaporate excess solvent to obtain a single-sided catalyst layer catalytic membrane, then spray the catalyst layer slurry on the other side of the proton exchange membrane, and also place it at 40°C for 1 hour to obtain a catalytic membrane having both an anode catalyst layer and a cathode catalyst layer; the total platinum loading of the anode catalyst layer and the cathode catalyst layer on both sides of the catalytic membrane is 0.5 mg/ ^cm2 , and the ratio of the platinum loading of the anode catalyst layer to the cathode catalyst layer is 1:4.

S3. One hot pressing: firstly, a PTFE film with a thickness of 0.8 mm is attached to both sides of the catalyst membrane to obtain an assembly a, and then a porous PTFE film with a porosity of 40% is attached to both sides of the assembly a to obtain an assembly b, and finally, a thin copper sheet with a thickness of 1 mm is assembled on both sides of the assembly b to obtain an assembly c; the assembly c is hot pressed once at 120°C and a pressure of 0.6 MPa for 120 seconds; after the hot pressing is completed, the thin copper sheets, the porous PTFE film and the PTFE film on both sides are peeled off respectively and in sequence to obtain a semi-finished hot pressing assisted enhanced catalytic membrane;

S4. Secondary hot pressing: Place a gas diffusion layer with a thickness of 220 μm on both sides of the semi-finished hot-pressing assisted enhanced catalytic membrane, load it into the mold of the hot press machine, and perform secondary hot pressing at 140°C and 3MPa pressure for 120s to obtain a fuel cell membrane electrode.

Example 3

A method for preparing a hot-pressing assisted enhanced fuel cell membrane electrode comprises the following steps:

S1. Preparation of catalytic layer slurry: 3.375 mL of distilled water and 64.125 mL of isopropanol were added to 0.5 g of Pt/CNTs (the mass percentage of platinum was 10%), and the mixture was stirred at 500 rpm for 30 min in a 30 W ultrasonic cleaner. Then, 0.875 g of perfluorosulfonic acid resin solution (the mass percentage was 20 wt%) was added, and the mixture was stirred at 10,000 rpm for 30 min at room temperature to obtain a uniformly dispersed ink-like catalyst slurry. The solvent of the catalyst slurry was water and isopropanol, and the volume ratio of water to isopropanol was 0.5:9.5. The solute was Pt/CNTs and perfluorosulfonic acid resin, and the mass percentage of the solute was 1%. The mass ratio of perfluorosulfonic acid resin to carbon nanotubes in Pt/CNTs was 0.7:1.

S2. Spraying: Place a 12 μm thick proton exchange membrane on a heating plate at 90°C, pour the catalyst layer slurry into a spray gun and spray it on one side of the proton exchange membrane, then place it at 40°C for 1 hour to evaporate excess solvent to obtain a single-sided catalyst layer catalytic membrane, then spray the catalyst layer slurry on the other side of the proton exchange membrane, and also place it at 40°C for 1 hour to obtain a catalytic membrane having both an anode catalyst layer and a cathode catalyst layer; the total platinum loading of the anode catalyst layer and the cathode catalyst layer on both sides of the catalytic membrane is 0.5 mg/ ^cm2 , and the ratio of the platinum loading of the anode catalyst layer to the cathode catalyst layer is 1:4.

S3. One hot pressing: firstly, a PTFE film with a thickness of 0.4 mm is attached to both sides of the catalyst membrane to obtain an assembly a, and then a porous PTFE film with a porosity of 20% is attached to both sides of the assembly a to obtain an assembly b, and finally, a thin copper sheet with a thickness of 1 mm is assembled on both sides of the assembly b to obtain an assembly c; the assembly c is hot pressed once at 100°C and a pressure of 0.4 MPa for 80 seconds; after the hot pressing is completed, the thin copper sheets, the porous PTFE film and the PTFE film on both sides are peeled off respectively and in sequence to obtain a semi-finished hot-pressing assisted enhanced catalytic membrane;

S4. Secondary hot pressing: Place a gas diffusion layer with a thickness of 220 μm on both sides of the semi-finished hot-pressing assisted enhanced catalytic membrane, load it into the mold of the hot press machine, and perform secondary hot pressing at 140°C and 3MPa pressure for 120s to obtain a fuel cell membrane electrode.

Example 4

A method for preparing a hot-pressing assisted enhanced fuel cell membrane electrode comprises the following steps:

S1. Preparation of catalytic layer slurry: 4.58 mL of distilled water and 41.25 mL of isopropanol were added to 0.5 g of Pt/CNTs (the mass percentage of platinum was 10%), and the mixture was stirred at 500 rpm for 30 min in a 30 W ultrasonic cleaner. Then, 0.9375 g of perfluorosulfonic acid resin solution (the mass percentage was 20 wt%) was added, and the mixture was stirred at 10,000 rpm for 30 min at room temperature to obtain a uniformly dispersed ink-like catalyst slurry. The solvent of the catalyst slurry was water and isopropanol, and the volume ratio of water to isopropanol was 1:9. The solute was Pt/CNTs and perfluorosulfonic acid resin, and the mass percentage of the solute was 1.5%. The mass ratio of perfluorosulfonic acid resin to carbon nanotubes in Pt/CNTs was 0.75:1.

S2. Spraying: Place a 12μm thick proton exchange membrane on a heating plate at 90°C, pour the catalyst layer slurry into a spray gun and spray it on one side of the proton exchange membrane, then place it at 40°C for 1 hour to evaporate excess solvent to obtain a single-sided catalyst layer catalytic membrane, then spray the catalyst layer slurry on the other side of the proton exchange membrane, and also place it at 40°C for 1 hour to obtain a catalytic membrane with both an anode catalyst layer and a cathode catalyst layer; the total platinum loading of the anode catalyst layer and the cathode catalyst layer on both sides of the catalytic membrane is 0.5mg/ ^cm2 , and the ratio of the platinum loading of the anode catalyst layer to the cathode catalyst layer is 1:4.

S3. One hot pressing: firstly, a PTFE film with a thickness of 0.6 mm is attached to both sides of the catalytic membrane to obtain an assembly a, and then a porous PTFE film with a porosity of 30% is attached to both sides of the assembly a to obtain an assembly b, and finally, a thin copper sheet with a thickness of 1 mm is assembled on both sides of the assembly b to obtain an assembly c; the assembly c is hot pressed once at 110°C and a pressure of 0.5 MPa for 100 s; after the hot pressing is completed, the thin copper sheets, the porous PTFE film and the PTFE film on both sides are peeled off respectively and in sequence to obtain a semi-finished hot pressing-assisted enhanced catalytic membrane;

S4. Secondary hot pressing: Place a gas diffusion layer with a thickness of 220 μm on both sides of the semi-finished hot-pressing assisted enhanced catalytic membrane, load it into the mold of the hot press machine, and perform secondary hot pressing at 140°C and 3MPa pressure for 120s to obtain a fuel cell membrane electrode.

Comparative Example 1

A method for preparing a hot-pressing assisted enhanced fuel cell membrane electrode comprises the following steps:

S1. Preparation of catalytic layer slurry: 5.25 mL of distilled water and 29.75 mL of isopropanol were added to 0.5 g of Pt/CNTs (the mass percentage of platinum was 10%), and the mixture was stirred at 500 rpm for 30 min in a 30 W ultrasonic cleaner. Then 1.0 g of perfluorosulfonic acid resin solution (the mass percentage was 20 wt%) was added, and the mixture was stirred at 10,000 rpm for 30 min at room temperature to obtain a uniformly dispersed ink-like catalyst slurry; the solvent of the catalyst slurry was water and isopropanol, and the volume ratio of water to isopropanol was 1.5:8.5; the solute was Pt/CNTs and perfluorosulfonic acid resin, and the mass percentage of the solute was 2%, and the mass ratio of perfluorosulfonic acid resin to carbon nanotubes in Pt/CNTs was 0.8:1.

S2. Spraying: Place a 12 μm thick proton exchange membrane on a heating plate at 90°C, pour the catalyst layer slurry into a spray gun and spray it on one side of the proton exchange membrane, then place it at 40°C for 1 hour to evaporate excess solvent to obtain a single-sided catalyst layer catalytic membrane, then spray the catalyst layer slurry on the other side of the proton exchange membrane, and also place it at 40°C for 1 hour to obtain a catalytic membrane having both an anode catalyst layer and a cathode catalyst layer; the total platinum loading of the anode catalyst layer and the cathode catalyst layer on both sides of the catalytic membrane is 0.5 mg/ ^cm2 , and the ratio of the platinum loading of the anode catalyst layer to the cathode catalyst layer is 1:4.

S3. Hot pressing: Place a gas diffusion layer with a thickness of 220 μm on both sides of the catalytic membrane, load it into the mold of a hot press, and perform hot pressing at 140°C and 3 MPa pressure for 120 seconds to obtain a fuel cell membrane electrode.

Example 5

Membrane electrode electrical performance test

A fuel cell test system was used. The reactants used in the system were compressed air and high-purity hydrogen. The system was equipped with an external humidification system. Different gas humidification effects were obtained by controlling the humidifier temperature. Before the test, the MEA was activated to ensure that the proton exchange membrane and the Nafion resin contained in the catalyst layer contained sufficient water to ensure sufficient conductivity. After the working conditions were stable, the battery was controlled to have different discharge currents or voltages. After the test, the experimental data were exported. The single cell of the fuel cell consists of a membrane electrode, a plate, a sealing gasket and an end plate. The plate is an airtight hard graphite plate with a size of 50×50×3mm, and the inner side is designed as a parallel serpentine three-flow channel; the sealing gasket is an ordinary plastic gasket; and a stainless steel plate is used as the end plate. The components are tightly assembled to reduce the internal resistance of the battery. The effective area of the membrane electrode in the homemade single cell is ^25cm2 . After the membrane electrode with an effective area of ^25cm2 was installed in the single experimental cell, the single cell performance test was carried out on the test bench. In the electrochemical performance test conditions of the membrane electrode, the humidity of hydrogen and oxygen is 50% RH, the hydrogen pressure and oxygen pressure are adjusted to 0.28MPa and 0.30MPa respectively, the single cell is connected to an external constant current and constant voltage power supply, the battery temperature is raised to 80℃, and the voltage-current curve of the battery is measured.

The membrane electrodes prepared in Examples 2-4 and Comparative Example 1 were tested according to the above test system, and the semi-finished hot-pressing assisted enhanced catalytic membrane obtained by hot pressing once in Example 2 and the catalytic membrane having both an anode catalytic layer and a cathode catalytic layer obtained by spraying in Comparative Example 1 were characterized by scanning electron microscopy (SEM) morphology;

The test results of Example 3 and Example 4 are shown in Table 1:

;

The polarization curves of Example 2 and Comparative Example 1 are shown in FIG2 . As can be seen from Table 1 and FIG2 , in Comparative Example 1 , the Pt/CNT catalytic membrane after spraying was not subjected to hot pressing and strengthening treatment, and the initial activation polarizations of the two membrane electrodes were substantially the same, because the activation polarization was only related to the intrinsic performance of the catalyst, and the catalysts used in Example 2 and Comparative Example 1 were the same, so the activation polarizations were also substantially the same; when the current density was increased, the battery voltage and power density of Example 2 were higher, because the carbon nanotubes subjected to the hot pressing and strengthening auxiliary treatment were more likely to form conductive paths between layers; Furthermore, Figure 3 is an SEM image of Example 2 and Comparative Example 1, wherein Figure 3A is the surface morphology of the semi-finished hot-pressing assisted enhanced catalytic membrane obtained by one hot pressing in Example 2, and Figure 3B is the surface morphology of the catalytic membrane having both an anode catalytic layer and a cathode catalytic layer obtained by spraying in Comparative Example 1. The surface morphology of the catalytic layer after hot pressing treatment is smoother than that of the catalyst that has not been hot pressed, indicating that more conductive pathways are formed, which can reduce the ohmic impedance and ohmic polarization of the membrane electrode, thereby improving the electrochemical performance of the membrane electrode fuel cell.

It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims (8)

1. A method for preparing a hot-pressing assisted enhanced fuel cell membrane electrode, characterized in that it comprises the following steps: S1. Preparation of catalyst layer slurry: Add water and isopropanol to Pt/CNTs with a mass percentage of 10% platinum, stir at 500rpm for 30min at an ultrasonic power of 30W, then add a 20wt% perfluorosulfonic acid resin solution, stir at 10000rpm for 30min at room temperature to obtain a uniformly dispersed catalyst slurry; the solvent of the catalyst slurry is water and isopropanol, the solute of the catalyst slurry is Pt/CNTs and perfluorosulfonic acid resin, and the mass percentage of the solute is 1-2%; S2. Spraying: The proton exchange membrane is placed on a heating plate at 90°C, and the catalyst layer slurry is sprayed on both sides of the proton exchange membrane in sequence to obtain a catalyst membrane having both an anode catalyst layer and a cathode catalyst layer; S3. One hot pressing: firstly, the PTFE film is attached to both sides of the catalyst membrane to obtain an assembly a, then the porous PTFE film is attached to both sides of the assembly a to obtain an assembly b, and finally, copper sheets with a thickness of 1 mm are assembled on both sides of the assembly b to obtain an assembly c; the assembly c is subjected to one hot pressing, and after the hot pressing is completed, the thin copper sheets, the porous PTFE film and the PTFE film on both sides are peeled off to obtain a semi-finished hot pressing assisted enhanced catalytic membrane; S4. Secondary hot pressing: placing the gas diffusion layer on both sides of the semi-finished hot pressing assisted enhanced catalyst membrane, and performing secondary hot pressing to obtain a fuel cell membrane electrode; The hot pressing conditions in S3 are hot pressing at 100-120 ° C and 0.4-0.6MPa pressure for 80-120s; The secondary hot pressing conditions in S4 are hot pressing at 140° C. and 3 MPa pressure for 120 s. 2. The method for preparing a hot-pressing assisted enhanced fuel cell membrane electrode according to claim 1, characterized in that the volume ratio of water to isopropanol in the solvent in S1 is 0.5-1.5:8.5-9.5. 3. The method for preparing a hot-pressing assisted enhanced fuel cell membrane electrode according to claim 1, characterized in that the mass ratio of the perfluorosulfonic acid resin in the solute in S1 to the carbon nanotubes in Pt/CNTs is 0.7-0.8:1. 4. A method for preparing a hot-pressing assisted enhanced fuel cell membrane electrode according to claim 1, characterized in that the total platinum loading of the anode catalyst layer and the cathode catalyst layer on both sides of the catalyst membrane in S2 is 0.5 mg/ ^cm2 , and the ratio of the platinum loading of the anode catalyst layer to the cathode catalyst layer is 1:4. 5. According to claim 1, a method for preparing a hot-pressing assisted enhanced fuel cell membrane electrode is characterized in that after the catalyst layer slurry in S2 is sprayed on one side of the proton exchange membrane, it is placed at 40°C for 1 hour to evaporate excess solvent to obtain a single-sided catalyst layer catalyst membrane, and then the catalyst layer slurry is sprayed on the other side of the proton exchange membrane, and is also placed at 40°C for 1 hour to obtain a catalyst membrane having both an anode catalyst layer and a cathode catalyst layer. 6. A method for preparing a hot-pressing assisted enhanced fuel cell membrane electrode according to claim 1, characterized in that the thickness of the proton exchange membrane in S2 is 12 μm, the thickness of the PTFE film in S3 is 0.4-0.8 mm, and the thickness of the gas diffusion layer in S4 is 220 μm. 7. A method for preparing a hot-pressing assisted enhanced fuel cell membrane electrode according to claim 1, characterized in that the porosity of the porous PTFE film in S3 is 20-40%. 8. A thermal press-assisted enhanced fuel cell membrane electrode, characterized in that it is prepared by the thermal press-assisted enhanced fuel cell membrane electrode preparation method according to any one of claims 1 to 7.