CN114864966A - A kind of preparation method of gas diffusion layer of proton exchange membrane fuel cell and product thereof - Google Patents

Abstract

The invention relates to a preparation method of a gas diffusion layer of a proton exchange membrane fuel cell and a product thereof, which comprises the steps of coating sizing agent of polydopamine grafted micron carbon particles on the surface of carbon paper by a rapid printing or coating technology; preparing a graphene oxide thin layer on the surface of the carbon paper by layer-by-layer self-assembly by using a graphene oxide sheet; assembling the nano carbon ball slurry on the surface of the carbon paper to form a continuous single-layer or multi-layer film; the gas diffusion layer was treated with PTFE emulsion to form a thin layer deposit of low surface energy. The method is characterized in that the difference of geometric characteristics among three material particles, namely conductive carbon black modified by polydopamine, graphene oxide and nano carbon spheres is utilized, a gradient pore structure is formed after the three material particles are coated layer by layer, a hydrophobic structure is formed by PTFE treatment, the water and gas guiding capacities of a gas diffusion layer are improved by constructing a gradient GDL, and the electrochemical reaction efficiency is improved. The carbon paper product has good mechanical strength and is easy to carry out subsequent processing and surface treatment operation.

Description

A kind of preparation method of gas diffusion layer of proton exchange membrane fuel cell and product thereof

technical field

The invention belongs to the technical field of fuel cell materials, and in particular relates to a preparation method of a gas diffusion layer of a proton exchange membrane fuel cell and a product thereof.

Background technique

Proton exchange membrane fuel cell (PEMFC) is considered to be the clean and efficient power generation technology of choice in the 21st century, and has received extensive attention in various fields such as energy, automobiles, and home appliances. Among them, the gas diffusion layer (GDL) plays an important role in water vapor mass transfer, current collection and support material in proton exchange membrane fuel cells (PEMFC). As a key core component, its microporous structure and interface wettability are the fuel The high power generation efficiency and long-term operation of the battery are escorted.

In the prior art, a microporous layer ( MPL). This process cannot precisely control the transfer of the slurry to the carbon paper macroporous base layer, and the transmission and spreading of the slurry in the carbon fiber array, which in turn affects the drying process of the slurry in the carbon fiber array and the final distribution of effective substances. The result will inevitably lead to structural defects of MPL micropores and uneven pore size distribution, which will cause water flooding and gas blocking during PEMFC operation, which is also one of the important problems currently faced by PEMFC.

Therefore, studying the construction principle of the ultrathin microporous layer barrier assembly and the interpretation of this key scientific issue can provide a theoretical basis for optimizing the MPL preparation process, and reduce the effect of the agglomerates of carbon particles/hydrophobic agents on the microstructure. The influence of the pore structure, electrical conductivity and pore size uniformity of the pore layer can effectively control the drying of the slurry, the cracking of the coating surface during the sintering process, and the wrinkling of the carbon paper when heated, thereby improving the "gas-liquid-electricity-thermal" selection of MPL. Sexual transmission performance.

In the prior art, there is no research similar to the construction of the super-thin microporous layer with uniform pore size assembled on the surface of the macroporous carbon paper substrate of the gas diffusion layer of the proton exchange membrane fuel cell of the present application, and there is no combination of PTFE to construct a hydrophilic and hydrophobic structure. A related report on GDLs with ordered, gradient pores.

SUMMARY OF THE INVENTION

Aiming at the problems existing in the design of the gas diffusion layer of the proton exchange membrane fuel cell in the prior art, the first object of the present invention is to provide a gas diffusion layer ultra-thin microporous layer stacked assembly construction, the gas diffusion layer (GDL) ) can significantly enhance the gas transmission and drainage function, effectively prevent flooding, improve the power and stability of the proton exchange membrane fuel cell, and help improve its efficiency, reduce its cost, and prolong its life.

The second object of the present invention is to provide a method for preparing a gas diffusion layer ultra-thin microporous layer stacked assembly structure, which utilizes micro-carbon particles, graphene oxide sheets, and nano-carbon balls to assemble gradient-changing pore sizes The structure is finally dipped and sintered with polytetrafluoroethylene emulsion (PTFE). The structure can reduce the occurrence of the GDL flooding phenomenon, improve the operating power and stability of the fuel cell, and the gradient structure is simple in preparation, low in cost, and conducive to mass production.

In order to achieve the above technical purpose, the present invention provides a preparation method of a gas diffusion layer of a proton exchange membrane fuel cell, wherein the gas diffusion layer is assembled and constructed by an ultra-thin microporous layer stacking method, which specifically includes the following steps:

Step 1) Coat the surface of carbon paper with a slurry of polydopamine grafted micron carbon particles by rapid printing or coating technology;

Step 2) using graphene oxide sheet, through layer-by-layer self-assembly on the surface of carbon paper, to prepare graphene oxide thin layer;

Step 3) using the nano-carbon ball slurry to form a continuous single-layer or multi-layer film on the surface of the carbon paper;

Step 4) The gas diffusion layer is treated with PTFE emulsion to form a thin layer deposition with low surface energy.

The above-mentioned method forms the assembly and construction effect of the ultra-thin microporous layer barrier.

As a preferred solution, the diameter of carbon spheres in the polydopamine-grafted micro-carbon particle slurry described in step 1) is 0.5-2 μm, and the mass fraction of carbon spheres in the slurry is 10-50%.

As a preferred solution, in step 2), the diameter of the graphene oxide is 0.1-2 μm, and the concentration of the graphene oxide aqueous solution is 2-10%.

As a preferred solution, when a roll coater is used to transfer the graphene oxide solution, the coating speed of the coater is 10-100 cm/min, and the diameter of the roll-coating rod is 0.635-1.27 cm.

As a preferred solution, the carbon nanospheres described in step 3) need to be dissolved in anhydrous ethanol, and prepared into a slurry with a mass fraction of 10-50%. coating operation.

As a preferred solution, the concentration of the PTFE emulsion is 3-5 wt%.

As a preferred solution, in step 4), the carbon paper is immersed in the PTFE emulsion, followed by drying and heat treatment.

As a preferred solution, in step 4), the program control of the heat treatment is: 0-350°C, heating time 20-60min; at 350°C, holding time 20-50min.

As a preferred solution, in step 4), nitrogen gas needs to be used to protect the reaction system during the heat treatment.

The present invention provides a method for preparing a gas diffusion layer of a proton exchange membrane fuel cell, the specific steps are as follows:

(1) Preparation of polydopamine-modified carbon particle solution

Select large carbon spheres with a diameter of 0.5-2 μm (measured by a laser particle size analyzer), then disperse them in an ethanol solution, and adjust the concentration between 2-10%, and then add carbon spheres with a mass fraction of 10-50% Polydopamine, stir evenly, use ultrasonic dispersion for 1 hour to make the carbon balls uniformly dispersed in the ethanol solution of polydopamine, and finally carry out purification treatment.

(2) Preparation of graphene oxide solution

Select graphene oxide with a diameter of 0.1-2 μm (measured by a laser particle size analyzer), prepare a graphene oxide aqueous solution with a concentration of 2-10%, and use ultrasonic dispersion for 1 h to make it uniformly dispersed.

(3) Preparation of carbon nanospheres

A certain amount of glucose was dissolved in deionized water to prepare a 1.5 mol/L glucose aqueous solution, which was transferred into a high-pressure reaction kettle, and the hydrothermal reaction was carried out at a constant temperature of 190 °C for 5 hours, and then cooled to room temperature naturally. The product was taken out from the reactor, separated and purified by a centrifuge, washed three times with ethanol and water, and dried in a vacuum drying oven at 90 °C for 12 h. The dried samples were placed in a tube furnace for carbonization at a high temperature of 600 °C for 10 h under nitrogen protection, and finally black powdery carbon nanospheres were obtained (the diameter of the carbon balls can be controlled in the range of 0.2-1 μm).

(4) Configuration of polytetrafluoroethylene (PTFE) emulsion

Weigh PTFE, add it into deionized water, disperse it ultrasonically for 30 minutes, and use magnetic stirring at 100 r/min for 2 hours to prepare a uniformly dispersed 3-5 wt% polytetrafluoroethylene emulsion.

(5) Coating of polydopamine-modified carbon particle solution on carbon paper surface

The modified carbon particle solution was transferred to the surface of carbon paper using a roll coating machine. During the coating process, the coating speed of the coating machine was controlled to be 10-100 cm/min, and the diameter of the roll coating rod was 0.635-1.27 cm.

(6) Coating of graphene oxide solution on carbon paper surface

The graphene oxide solution was transferred to the surface of the carbon paper using a roll coating machine. During the coating process, the coating speed of the coating machine was controlled to be 10-100 cm/min, and the diameter of the roll coating rod was 0.635-1.27 cm.

(7) Coating of carbon nanosphere solution on the surface of carbon paper

Dissolve the activated carbon nanospheres in absolute ethanol and prepare a slurry with a mass fraction of 10-50%. The surface of the paper was dried in a drying oven at 100 °C for 6 h after the surface of the sample was air-dried.

(8) Polytetrafluoroethylene (PTFE) emulsion dip coating and sintering

The obtained composite gas diffusion layer material was immersed in the PTFE ethanol solution for 5-10 minutes and then taken out. Air-dried at room temperature for 30 min, and then sintered at 350 °C for 20 min under nitrogen protection.

The preparation method of the present invention and the obtained product have the following advantages and beneficial effects:

(1) The preparation method of the ultra-thin microporous layer stacked assembly structure of the gas diffusion layer of the proton exchange membrane fuel cell of the present invention is simple, easy to operate, and suitable for industrial production;

(2) the use of polydopamine-modified conductive carbon black, graphene oxide and carbon nanospheres in the technical solution of the present invention has differences in geometric characteristics, and a gradient pore structure is formed after layer-by-layer coating, At the same time, the hydrophobic structure is formed by PTFE treatment, and the water and gas conductivity of the gas diffusion layer is improved by constructing a gradient GDL, and the electrochemical reaction efficiency is improved.

(3) After the treatment is completed, the PEM fuel cell gas diffusion layer ultra-thin microporous layer stacked assembly structure carbon paper still maintains good mechanical strength, is easy to carry out subsequent processing and surface treatment operations, and has good application prospects.

In order to make the purpose and technical solutions of the specific embodiments of the present invention clearer, the technical solutions of the specific embodiments of the present invention will be clearly and completely described below with reference to the implementation examples of the specific embodiments of the present invention. Obviously, the described embodiments are some, but not all, embodiments of the present invention. Based on the described specific embodiments of the present invention, all other specific embodiments prepared by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

Detailed ways

The preferred embodiments of the present invention will be described below, and it should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, but not to limit the present invention.

Example 1

Take 0.13mm thick carbon paper and cut it into 6cm×12cm

The GDLs of the triple-stacked MPL were prepared on carbon paper. The loading of carbon materials in each layer of MPL in the stacked structure is the same, and the total amount is 0.8 mg/cm2. According to the particle size of the carbon material, the coating sequence is: slurry III/slurry II/slurry I/carbon paper. Slurry I: Select large carbon spheres with a diameter of 0.5-2 μm, and then disperse them in an ethanol solution with a concentration of 2%, then add polydopamine with a mass fraction of 10% of carbon spheres, stir evenly, and use ultrasonic dispersion 1h to make the carbon balls disperse uniformly in the polydopamine ethanol solution; Slurry II: select graphene oxide with a diameter of 0.1-2 μm, prepare a graphene oxide aqueous solution with a concentration of 2%, and use ultrasonic dispersion for 1h to make it evenly dispersed; Slurry Material III: Dissolve glucose in deionized water to prepare a 1.5 mol/L glucose aqueous solution, transfer it into a high pressure reactor, conduct hydrothermal reaction at a constant temperature of 190 °C for 5 hours, and then naturally cool to room temperature. The product was separated and purified by centrifuge, washed three times with ethanol and water, and dried in a vacuum drying oven at 90 °C for 12 h. The dried samples were carbonized at a high temperature of 600 °C for 10 h under nitrogen protection in a tube furnace, and finally nano carbon balls with a diameter of 0.2-1 μm were obtained. Dissolve the activated carbon nanospheres in absolute ethanol, prepare a slurry with a concentration of 2%, and disperse them uniformly by an ultrasonic oscillator.

The surface of the carbon paper is coated in three layers using a roll coater. After the slurry I was coated on the surface of the carbon paper, the surface of the sample was air-dried, dried in a drying oven at 100 °C for 6 h, then the slurry II was coated on the surface of the slurry III, dried and heat-treated, and then the slurry III was coated on the surface of the carbon paper. Slurry II was surface dried and heat treated.

Weigh the polytetrafluoroethylene, add it into deionized water, ultrasonically disperse it for 30 minutes, and use magnetic stirring at 100 r/min for 2 hours to obtain a uniformly dispersed 3wt% polytetrafluoroethylene emulsion. The obtained composite gas diffusion layer material was immersed in PTFE ethanol solution for 5 min and then taken out. Air-dried at room temperature for 30 min, and then sintered at 350 °C for 20 min under nitrogen protection.

Example 2

Take 0.13mm thick carbon paper and cut it into 6cm×12cm

The GDLs of the triple-stacked MPL were prepared on carbon paper. The loadings of carbon materials in each layer of MPL in the stacked structure are the same, and the total amount is 1.6 mg/cm2. According to the particle size of the carbon material, the coating sequence is: slurry III/slurry II/slurry I/carbon paper. Slurry I: Select large carbon spheres with a diameter of 0.5-2 μm, then disperse them in an ethanol solution with a concentration of 6%, then add polydopamine with a mass fraction of 20% of carbon spheres, stir evenly, and use Ultrasonic dispersion for 1 hour makes the carbon spheres disperse uniformly in the polydopamine ethanol solution; Slurry II: select graphene oxide with a diameter of 0.1-2 μm, prepare a graphene oxide aqueous solution with a concentration of 6%, and use ultrasonic dispersion for 1 hour to make it uniformly dispersed ; Slurry III: Dissolve glucose in deionized water to prepare a 1.5 mol/L glucose aqueous solution, transfer it into a high-pressure reactor, conduct hydrothermal reaction at a constant temperature of 190 ° C for 5 hours, and then naturally cool to room temperature. The product was separated and purified by centrifuge, washed three times with ethanol and water, and dried in a vacuum drying oven at 90 °C for 12 h. The dried samples were carbonized at a high temperature of 600 °C for 10 h under nitrogen protection in a tube furnace, and finally nano carbon balls with a diameter of 0.2-1 μm were obtained. Dissolve the activated carbon nanospheres in absolute ethanol, prepare a slurry with a concentration of 5%, and disperse evenly by an ultrasonic oscillator

The surface of the carbon paper is coated in three layers using a roll coater. After the slurry I was coated on the surface of the carbon paper, the surface of the sample was air-dried, dried in a drying oven at 100 °C for 6 h, then the slurry II was coated on the surface of the slurry III, dried and heat-treated, and then the slurry III was coated on the surface of the carbon paper. Slurry II was surface dried and heat treated.

Weigh the polytetrafluoroethylene, add it into deionized water, ultrasonically disperse it for 30 minutes, and use magnetic stirring at 100 r/min for 2 hours to prepare a uniformly dispersed 5wt% polytetrafluoroethylene emulsion. The obtained composite gas diffusion layer material was immersed in PTFE ethanol solution for 10 min and then taken out. Air-dried at room temperature for 45 min, and then sintered at 350 °C for 20 min under nitrogen protection.

Example 3

Take 0.13mm thick carbon paper and cut it into 6cm×12cm

The GDLs of the triple-stacked MPL were prepared on carbon paper. The loadings of carbon materials in each layer of MPL in the stacked structure are the same, and the total amount is 2.4 mg/cm2. According to the particle size of the carbon material, the coating sequence is: slurry III/slurry II/slurry I/carbon paper. Slurry I: Select large carbon spheres with a diameter of 0.5-2 μm, then disperse them in an ethanol solution with a concentration of 8%, then add polydopamine with a carbon sphere mass fraction of 30%, stir evenly, and use Ultrasonic dispersion for 1 hour makes the carbon spheres uniformly dispersed in the polydopamine ethanol solution; Slurry II: select graphene oxide with a diameter of 0.1-2 μm, prepare a graphene oxide aqueous solution with a concentration of 10%, and use ultrasonic dispersion for 1 hour to make it uniformly dispersed ; Slurry III: Dissolve glucose in deionized water to prepare a 1.5 mol/L glucose aqueous solution, transfer it into a high-pressure reactor, conduct hydrothermal reaction at a constant temperature of 190 ° C for 5 hours, and then naturally cool to room temperature. The product was separated and purified by centrifuge, washed three times with ethanol and water, and dried in a vacuum drying oven at 90 °C for 12 h. The dried samples were carbonized at a high temperature of 600 °C for 10 h under nitrogen protection in a tube furnace, and finally nano carbon balls with a diameter of 0.2-1 μm were obtained. Dissolve the activated carbon nanospheres in absolute ethanol, prepare a slurry with a concentration of 8%, and disperse evenly by an ultrasonic oscillator

The surface of the carbon paper is coated in three layers using a roll coater. After the slurry I was coated on the surface of the carbon paper, the surface of the sample was air-dried, dried in a drying oven at 100 °C for 6 h, then the slurry II was coated on the surface of the slurry III, dried and heat-treated, and then the slurry III was coated on the surface of the carbon paper. Slurry II was surface dried and heat treated.

Weigh the polytetrafluoroethylene, add it into deionized water, ultrasonically disperse it for 30 minutes, and use magnetic stirring at 100 r/min for 2 hours to obtain a uniformly dispersed 3wt% polytetrafluoroethylene emulsion. The obtained composite gas diffusion layer material was immersed in PTFE ethanol solution for 6 min and then taken out. Air-dried at room temperature for 15 min, and then sintered at 350 °C for 25 min under nitrogen protection.

Example 4

Take 0.13mm thick carbon paper and cut it into 6cm×12cm

The GDLs of the triple-stacked MPL were prepared on carbon paper. The loading of carbon materials in each layer of MPL in the stacked structure is the same, and the total amount is 1.2 mg/cm2. According to the particle size of the carbon material, the coating sequence is: slurry III/slurry II/slurry I/carbon paper. Slurry I: Select large carbon spheres with a diameter of 0.5-2 μm, and then disperse them in an ethanol solution with a concentration of 10%, then add polydopamine with a carbon sphere mass fraction of 50%, stir evenly, and use Ultrasonic dispersion for 1 hour makes the carbon spheres uniformly dispersed in the polydopamine ethanol solution; Slurry II: select graphene oxide with a diameter of 0.1-2 μm, prepare a graphene oxide aqueous solution with a concentration of 10%, and use ultrasonic dispersion for 1 hour to make it uniformly dispersed ; Slurry III: Dissolve glucose in deionized water to prepare a 1.5 mol/L glucose aqueous solution, transfer it into a high-pressure reactor, conduct hydrothermal reaction at a constant temperature of 190 ° C for 5 hours, and then naturally cool to room temperature. The product was separated and purified by centrifuge, washed three times with ethanol and water, and dried in a vacuum drying oven at 90 °C for 12 h. The dried samples were carbonized at a high temperature of 600 °C for 10 h under nitrogen protection in a tube furnace, and finally nano carbon balls with a diameter of 0.2-1 μm were obtained. Dissolve the activated carbon nanospheres in absolute ethanol, prepare a slurry with a concentration of 8%, and disperse evenly by an ultrasonic oscillator

The surface of the carbon paper is coated in three layers using a roll coater. After the slurry I was coated on the surface of the carbon paper, the surface of the sample was air-dried, dried in a drying oven at 100 °C for 6 h, then the slurry II was coated on the surface of the slurry III, dried and heat-treated, and then the slurry III was coated on the surface of the carbon paper. Slurry II was surface dried and heat treated.

Weigh the polytetrafluoroethylene, add it into deionized water, ultrasonically disperse it for 30 minutes, and use magnetic stirring at 100 r/min for 2 hours to obtain a uniformly dispersed 3-5 wt% polytetrafluoroethylene emulsion. The obtained composite gas diffusion layer material was immersed in PTFE ethanol solution for 8 minutes and then taken out. Air-dried at room temperature for 30 min, and then sintered at 350 °C for 30 min under nitrogen protection.

The specific implementation of the technical solution of the present invention is further described above with reference to the specific embodiments, and the specific implementation is for the detailed description of the technical solution, rather than for limiting the technical solution. The specific embodiments described above are only to describe the preferred embodiments of the present invention, and do not limit the technical concept and protection scope of the present invention. Various modifications and improvements made should fall within the protection scope of the present invention.

Claims (10)

1. a preparation method of proton exchange membrane fuel cell gas diffusion layer, it is characterized in that described gas diffusion layer is assembled and constructed by ultra-thin microporous layer barrier mode, specifically comprises the following steps: Step 1) Coat the surface of carbon paper with a slurry of polydopamine grafted micron carbon particles by rapid printing or coating technology; Step 2) using graphene oxide sheet, through layer-by-layer self-assembly on the surface of carbon paper, to prepare graphene oxide thin layer; Step 3) using the nano-carbon ball slurry to form a continuous single-layer or multi-layer film on the surface of the carbon paper; Step 4) The gas diffusion layer is treated with PTFE emulsion to form a thin layer deposition with low surface energy. 2. The method for preparing a gas diffusion layer of a proton exchange membrane fuel cell according to claim 1, wherein the diameter of the carbon ball in the polydopamine-grafted micron carbon particle slurry described in the step 1) is 0.5 ~2μm, the mass fraction of carbon balls in the slurry is 10-50%. 3. the preparation method of a kind of proton exchange membrane fuel cell gas diffusion layer according to claim 1, is characterized in that described in the step 2), the graphene oxide diameter is 0.1～2 μm, and the graphene oxide aqueous solution concentration is 2 ~10%. 4. the preparation method of a kind of proton exchange membrane fuel cell gas diffusion layer according to claim 1, is characterized in that when using roll coater to transfer graphene oxide solution, the coating speed of coater is 10～100cm /min, the diameter of the roller coating rod is 0.635 to 1.27 cm. 5. the preparation method of a kind of proton exchange membrane fuel cell gas diffusion layer according to claim 1, it is characterized in that the carbon nano-ball described in the described step 3) needs to be dissolved in absolute ethanol, and be mixed with quality After the slurry with a fraction of 10-50% is uniformly dispersed by an ultrasonic oscillator, a coating operation is performed on the surface of the carbon paper. 6 . The method for preparing a gas diffusion layer of a proton exchange membrane fuel cell according to claim 1 , wherein the concentration of the PTFE emulsion is 3-5 wt %. 7 . 7. The preparation method of a proton exchange membrane fuel cell gas diffusion layer according to claim 1, characterized in that in the step 4), the carbon paper is placed in a PTFE emulsion for dipping, followed by drying and heat treatment. 8 . The method for preparing a gas diffusion layer of a proton exchange membrane fuel cell according to claim 1 , wherein in the step 4), the program control of the heat treatment is: 0～350° C., and the heating time is 20～60min; 9 . At 350°C, the holding time is 20-50min. 9. the preparation method of a kind of proton exchange membrane fuel cell gas diffusion layer according to claim 1, is characterized in that described method concrete steps are as follows: (1) Preparation of polydopamine-modified carbon particle solution Select large carbon spheres with a diameter of 0.5-2 μm (measured by a laser particle size analyzer), then disperse them in an ethanol solution, and adjust the concentration between 2-10%, and then add carbon spheres with a mass fraction of 10-50% Polydopamine, stir evenly, use ultrasonic dispersion for 1 hour to make the carbon balls uniformly dispersed in the ethanol solution of polydopamine, and finally carry out purification treatment; (2) Preparation of graphene oxide solution Select graphene oxide with a diameter of 0.1-2 μm (measured by a laser particle size analyzer), prepare an aqueous solution of graphene oxide with a concentration of 2-10%, and use ultrasonic dispersion for 1 h to make it uniformly dispersed; (3) Preparation of carbon nanospheres Dissolve a certain amount of glucose in deionized water to prepare a 1.5mol/L glucose aqueous solution, transfer it into an autoclave, conduct hydrothermal reaction at a constant temperature of 190°C for 5 hours, and then naturally cool to room temperature; take out the product from the reaction kettle and use a centrifuge After separation and purification, washed with ethanol and water for 3 times, dried in a vacuum drying oven at 90 °C for 12 hours; the dried samples were placed in a tube furnace under nitrogen protection and carbonized at a high temperature of 600 °C for 10 hours, and finally a black powdery nanometer was obtained. Carbon balls (the diameter of carbon balls can be controlled in the range of 0.2 to 1 μm); (4) Configuration of polytetrafluoroethylene (PTFE) emulsion Weigh the PTFE, add it into deionized water, disperse it ultrasonically for 30 minutes, and use magnetic stirring at 100 r/min for 2 hours to prepare a uniformly dispersed 3-5wt% PTFE emulsion; (5) Coating of polydopamine-modified carbon particle solution on carbon paper surface Transfer the modified carbon particle solution to the surface of the carbon paper using a roll coating machine, and control the coating speed of the coating machine to be 10-100 cm/min and the diameter of the roll coating rod to be 0.635-1.27 cm during the coating process; (6) Coating of graphene oxide solution on carbon paper surface The graphene oxide solution is transferred to the surface of the carbon paper using a roll coating machine, and the coating speed of the coating machine is controlled to be 10-100cm/min and the diameter of the roll-coating rod is 0.635-1.27cm during the coating process; (7) Coating of carbon nanosphere solution on the surface of carbon paper Dissolve the activated carbon nanospheres in anhydrous ethanol, and prepare a slurry with a mass fraction of 10-50%. After the surface of the paper is air-dried, it is dried in a drying oven at 100 °C for 6 hours; (8) Polytetrafluoroethylene (PTFE) emulsion dip coating and sintering The obtained composite gas diffusion layer material was immersed in a PTFE ethanol solution for 5-10 minutes and taken out; air-dried for 30 minutes at room temperature, and then sintered at a high temperature of 350° C. for 20 minutes under nitrogen protection. 10. The method for preparing a gas diffusion layer of a proton exchange membrane fuel cell according to any one of claims 1-9, and the prepared gas diffusion layer product of a proton exchange membrane fuel cell.