Gas diffusion layer for hydrogen energy fuel cell and preparation method of gas diffusion layer

Abstract

The invention relates to the technical field of hydrogen energy fuel cells, and discloses a gas diffusion layer for a hydrogen energy fuel cell and a preparation method of the gas diffusion layer. The substrate layer is prepared from the following components: modified short carbon fibers, a binder and a dispersing agent; the microporous layer is prepared from the following components in parts by weight: carbon powder, carbon nanotubes and polytetrafluoroethylene emulsion; the hydrogen energy fuel cell prepared by the invention has the following characteristics: high conductivity: high-efficiency conduction of electrons in the cell can be ensured, and meanwhile, energy loss is reduced; high gas permeability: reaction gas can be quickly and uniformly transmitted to a catalyst layer, so that the cell efficiency is improved; the water management capability is excellent, water generation and discharge can be balanced, and the phenomenon of water flooding or film drying is avoided; the chemical stability is high, and the performance can be kept stable in an acidic or alkaline environment; the mechanical strength is higher, and various pressures in the battery assembly and operation can be borne.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen energy fuel cells, and particularly to a gas diffusion layer for a hydrogen energy fuel cell and a preparation method thereof. Background Art

[0002] With the development and progress of society, the sustainable development strategy has become the theme of today. Starting from the fact that the main source of energy was fossil energy at the beginning, to the current renewable energy sources such as hydropower, nuclear power, wind energy, solar energy, hydrogen energy, etc. These methods produce much less environmental pollution compared to traditional fossil energy. Among these newly emerged energy sources compared to the traditional ones, hydrogen energy produces the least pollution because its reaction product is only water.

[0003] A hydrogen energy fuel cell is an electrochemical device that directly converts the chemical energy of hydrogen into electrical energy. Its working principle is to generate water through the electrochemical reaction of hydrogen and oxygen, and release electrical energy during this process. Hydrogen energy fuel cells have the characteristics of high efficiency, cleanliness, and no pollution.

[0004] The gas diffusion layer (GDL) is one of the key components in a hydrogen energy fuel cell, located between the catalyst layer and the bipolar plate. Its main functions include: gas transport: evenly distributing the reaction gases (hydrogen and oxygen) to the catalyst layer; electron conduction: conducting electrons as part of the electrode; water management: discharging the water generated by the reaction to prevent flooding; mechanical support: providing structural support for the membrane electrode assembly (MEA).

[0005] It can be seen that the gas diffusion layer has a direct impact on the performance of the hydrogen energy fuel cell. In order to further improve the performance of the hydrogen energy fuel cell, we propose a gas diffusion layer for a hydrogen energy fuel cell. Summary of the Invention

[0006] (1) Technical Problems to be Solved

[0007] Aiming at the deficiencies of the prior art, the present invention provides a gas diffusion layer for a hydrogen energy fuel cell and a preparation method thereof.

[0008] (2) Technical Solutions

[0009] To achieve the above object, the present invention provides the following technical solutions:

[0010] A gas diffusion layer for a hydrogen energy fuel cell includes: a base layer and a microporous layer;

[0011] The base layer is made of the following components by weight: 80 - 85 parts of modified short carbon fibers, 4 - 6 parts of binder, and 1 - 2 parts of dispersant;

[0012] The dispersant is a mixture of sodium dodecylbenzenesulfonate and polyacrylic acid;

[0013] Among them, the mixing mass ratio of sodium dodecylbenzenesulfonate and polyacrylic acid is 5:1.

[0014] The microporous layer is made of the following components by weight: 10-12 parts of carbon powder, 2-3 parts of carbon nanotubes, and 35-40 parts of polytetrafluoroethylene emulsion;

[0015] The solid content of the polytetrafluoroethylene emulsion is 60%, the pH is 9.0, and the viscosity is 35 mPa·s.

[0016] As a further technical solution, the preparation method of the modified short carbon fiber is as follows:

[0017] First, add the short carbon fiber to acetone, soak it at room temperature for 30 min, then ultrasonically clean it for 20 min, and then filter and dry it;

[0018] Add the cleaned short carbon fiber to a concentrated sulfuric acid solution, adjust the temperature to 65 °C, keep it warm and stir for 1.5 hours, then filter, wash it with water until neutral, and dry it to obtain pretreated short carbon fiber;

[0019] Mix the silane coupling agent and ethanol at a volume ratio of 1:10, stir evenly, then add deionized water to make the hydrolysis mass concentration of the silane coupling agent 1.2%-1.5%, continue to stir for 40 min, then add maleic anhydride, and continue to stir for 30 min to obtain a modified treatment solution;

[0020] Add the pretreated short carbon fiber to the modified treatment solution, adjust the temperature to 52 °C, keep it warm and stir for 2 hours, then carry out suction filtration, rinse it with deionized water for 10 min, and then place it in a drying oven and dry it for 1 hour;

[0021] Among them, the drying temperature is 108 °C.

[0022] As a further technical solution, the length of the short carbon fiber is 6 mm;

[0023] The diameter of the short fiber is 7 μm.

[0024] As a further technical solution, the mixing ratio of the cleaned short carbon fiber and the concentrated sulfuric acid solution is 30 g:120 mL;

[0025] Among them, the mass fraction of concentrated sulfuric acid is 90%.

[0026] As a further technical solution: the silane coupling agent is KH-550.

[0027] As a further technical solution: the mass ratio of maleic anhydride to silane coupling agent is 1:3.

[0028] As a further technical solution: the mixing ratio of the pretreated chopped carbon fiber and the modified treatment liquid is 25 g: 110 mL.

[0029] As a further technical solution: the binder is composed of water-based acrylic resin and polyvinyl alcohol;

[0030] A method for preparing a gas diffusion layer for a hydrogen energy fuel cell: includes the following steps:

[0031] Preparation of the base layer:

[0032] Add the modified chopped carbon fiber, binder, and dispersant together by weight to obtain a preliminary mixture, and then add water to the preliminary mixture and continue stirring to obtain a slurry;

[0033] Sheet the obtained slurry into paper, and after drying, obtain carbon fiber paper;

[0034] Subject the obtained carbon fiber paper to high-temperature carbonization treatment to obtain the base layer;

[0035] Preparation of the microporous layer:

[0036] Mix carbon powder, carbon nanotubes, and polytetrafluoroethylene emulsion together by weight to obtain a spraying slurry;

[0037] Spray the obtained spraying slurry evenly onto the base layer, and after high-temperature sintering and cooling, form a microporous layer.

[0038] As a further technical solution: the thickness of the base layer is 150 μm;

[0039] The thickness of the microporous layer is 50 μm;

[0040] The temperature of the high-temperature carbonization treatment is 550 °C and the time is 40 min;

[0041] The temperature of the high-temperature sintering is 720 °C and the time is 30 min.

[0042] (III) Beneficial effects

[0043] Compared with the prior art, the present invention provides a gas diffusion layer for a hydrogen energy fuel cell, having the following beneficial effects:

[0044] The hydrogen energy fuel cell prepared by the present invention has the following characteristics: high electrical conductivity: it can ensure the efficient conduction of electrons in the battery while reducing energy loss; relatively high gas permeability: it can ensure the rapid and uniform transmission of reaction gases to the catalyst layer, improving the battery efficiency; excellent water management ability: it can balance the generation and discharge of water, avoiding the occurrence of flooding or membrane drying; relatively high chemical stability: it can maintain stable performance in acidic or alkaline environments; relatively high mechanical strength: it can withstand various pressures during battery assembly and operation.

[0045] By modifying the chopped carbon fibers in the present invention, the strength can be improved: with the increase of the self-strength of the chopped carbon fibers, the mechanical properties such as the tensile strength and tear strength of the prepared carbon fiber paper can be enhanced. Because in the carbon fiber paper, the chopped carbon fibers are intertwined with each other to form a network structure, and the high-strength chopped carbon fibers can better withstand external forces, reducing the fracture and slippage of the fibers when stressed, thereby improving the overall mechanical stability of the carbon fiber paper and making it less likely to be damaged during subsequent processing and use.

[0046] By modifying the chopped carbon fibers in the present invention, the pore structure can also be significantly improved, specifically including:

[0047] Porosity adjustment: The shape and size distribution of the chopped carbon fibers are more uniform, making the porosity of the prepared carbon fiber paper easier to control and more evenly distributed. The uniform fiber distribution can form a regular pore network, which is beneficial to the transmission of gases and liquids in the carbon fiber paper.

[0048] Pore size optimization: By improving the surface characteristics of the chopped carbon fibers, such as surface roughness, etc., the pore size of the carbon fiber paper can be changed to a certain extent. Appropriate pore size is crucial for subsequent applications in fuel cells and can affect gas diffusion and water management performance.

[0049] Conductivity improvement: The enhancement of the conductive performance further increases the conductivity of the carbon fiber paper. In the carbon fiber paper, good conductive performance can make the transmission of electrons between the fibers smoother, reducing the resistance during electron transmission, which is beneficial to the collection and conduction of electrons in the fuel cell.

[0050] Using the carbon fiber paper made of modified chopped carbon fibers as an important part of the gas diffusion layer, the optimization of its pore structure can improve the gas diffusion performance of the gas diffusion layer. The uniform pore distribution and appropriate pore size can provide a smoother channel for reaction gases such as hydrogen and oxygen, enabling the gases to diffuse more quickly and evenly to the surface of the catalyst layer, improving the electrochemistry reaction efficiency; the good pore structure and appropriate surface hydrophobicity of the carbon fiber paper can make the drainage performance of the gas diffusion layer better. During the operation of the fuel cell, it can timely discharge the generated water, avoid the occurrence of flooding, ensure the smoothness of the gas transmission channel, and maintain the stable operation of the battery. Detailed implementation manners

[0051] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0052] Embodiment 1

[0053] A gas diffusion layer for a hydrogen energy fuel cell, comprising: a base layer and a microporous layer;

[0054] The thickness of the base layer is 150 μm;

[0055] The thickness of the microporous layer is 50 μm;

[0056] The base layer is made of the following components by weight: 80 parts of modified short carbon fibers, 4 parts of binder, and 1 part of dispersant;

[0057] The dispersant is a mixture of sodium dodecylbenzenesulfonate and polyacrylic acid;

[0058] Among them, the mass ratio of sodium dodecylbenzenesulfonate to polyacrylic acid in the mixture is 5:1.

[0059] The microporous layer is made of the following components by weight: 10 parts of carbon powder, 2 parts of carbon nanotubes, and 35 parts of polytetrafluoroethylene emulsion;

[0060] The solid content of the polytetrafluoroethylene emulsion is 60%, the pH is 9.0, and the viscosity is 35 mPa·s.

[0061] The preparation method of the modified short carbon fibers is as follows:

[0062] First, add the short carbon fibers to acetone, soak at room temperature for 30 min, then ultrasonically clean for 20 min, and then filter and dry;

[0063] Add the cleaned short carbon fibers to a concentrated sulfuric acid solution, adjust the temperature to 65 °C, keep warm and stir for 1.5 hours, then filter, wash with water until neutral, and dry to obtain pretreated short carbon fibers;

[0064] Mix the silane coupling agent and ethanol at a volume ratio of 1:10, stir evenly, then add deionized water to make the hydrolysis mass concentration of the silane coupling agent 1.2%, continue to stir for 40 min, then add maleic anhydride, and continue to stir for 30 min to obtain a modified treatment solution;

[0065] Add the pretreated chopped carbon fibers to the modified treatment solution, adjust the temperature to 52 °C, keep warm and stir for 2 hours, then perform suction filtration, rinse with deionized water for 10 min, and then place it in a drying oven for drying for 1 hour. That's it.

[0066] Among them, the drying temperature is 108 °C.

[0067] The length of the chopped carbon fibers is 6 mm;

[0068] The diameter of the chopped fibers is 7 μm.

[0069] The mixing ratio of the chopped carbon fibers after cleaning and the concentrated sulfuric acid solution is 30 g: 120 mL;

[0070] Among them, the mass fraction of concentrated sulfuric acid is 90%.

[0071] The silane coupling agent is KH-550.

[0072] The mass ratio of maleic anhydride to the silane coupling agent is 1:3.

[0073] The mixing ratio of the pretreated chopped carbon fibers and the modified treatment solution is 25 g: 110 mL.

[0074] The binder is composed of water-based acrylic resin and polyvinyl alcohol;

[0075] A method for preparing a gas diffusion layer for a hydrogen energy fuel cell: includes the following steps:

[0076] Preparation of the base layer:

[0077] Add the modified chopped carbon fibers, binder, and dispersant together by weight to obtain a preliminary mixture, and then add water to the preliminary mixture and continue stirring to obtain a slurry;

[0078] Sheet the obtained slurry into paper, and after drying, obtain carbon fiber paper;

[0079] Perform high-temperature carbonization treatment on the obtained carbon fiber paper to obtain the base layer;

[0080] Preparation of the microporous layer:

[0081] Mix carbon powder, carbon nanotubes, and polytetrafluoroethylene emulsion together by weight to obtain a spraying slurry;

[0082] Spray the obtained spraying slurry evenly on the base layer, and after high-temperature sintering and cooling, form a microporous layer.

[0083] The high-temperature carbonization treatment temperature is 550 °C and the time is 40 min;

[0084] The high-temperature sintering temperature is 720 °C and the time is 30 min.

[0085] Example 2

[0086] A gas diffusion layer for a hydrogen energy fuel cell, comprising: a base layer and a microporous layer;

[0087] The thickness of the base layer is 150 μm;

[0088] The thickness of the microporous layer is 50 μm;

[0089] The base layer is made of the following components by weight: 82 parts of modified short carbon fibers, 5 parts of binder, and 1.5 parts of dispersant;

[0090] The dispersant is a mixture of sodium dodecylbenzenesulfonate and polyacrylic acid;

[0091] Among them, the mass ratio of sodium dodecylbenzenesulfonate to polyacrylic acid in the mixture is 5:1.

[0092] The microporous layer is made of the following components by weight: 11 parts of carbon powder, 2.5 parts of carbon nanotubes, and 38 parts of polytetrafluoroethylene emulsion;

[0093] The polytetrafluoroethylene emulsion has a solid content of 60%, a pH of 9.0, and a viscosity of 35 mPa·s.

[0094] The preparation method of the modified short carbon fibers is as follows:

[0095] First, add the short carbon fibers to acetone, soak at room temperature for 30 min, then ultrasonically clean for 20 min, and then filter and dry;

[0096] Add the cleaned short carbon fibers to a concentrated sulfuric acid solution, adjust the temperature to 65 °C, keep stirring for 1.5 hours, then filter, wash with water until neutral, and dry to obtain pretreated short carbon fibers;

[0097] Mix the silane coupling agent and ethanol at a volume ratio of 1:10, stir evenly, then add deionized water to make the hydrolysis mass concentration of the silane coupling agent 1.3%, continue stirring for 40 min, and then add maleic anhydride and continue stirring for 30 min to obtain a modified treatment solution;

[0098] Add the pretreated short carbon fibers to the modified treatment solution, adjust the temperature to 52 °C, keep stirring for 2 hours, then perform suction filtration, rinse with deionized water for 10 min, and then place in a drying oven and dry for 1 hour;

[0099] Among them, the drying temperature is 108 °C.

[0100] The length of the short carbon fibers is 6 mm;

[0101] The diameter of the short fibers is 7 μm.

[0102] The mixing ratio of the chopped carbon fibers after cleaning and the concentrated sulfuric acid solution is 30 g: 120 mL;

[0103] Among them, the mass fraction of the concentrated sulfuric acid is 90%.

[0104] The silane coupling agent is KH-550.

[0105] The mass ratio of maleic anhydride to the silane coupling agent is 1:3.

[0106] The mixing ratio of the pretreated chopped carbon fibers and the modification treatment liquid is 25 g: 110 mL.

[0107] The binder is composed of water-based acrylic resin and polyvinyl alcohol;

[0108] A method for preparing a gas diffusion layer for a hydrogen energy fuel cell: includes the following steps:

[0109] Preparation of the base layer:

[0110] Add the modified chopped carbon fibers, binder, and dispersant together by weight to obtain a preliminary mixture, and then add water to the preliminary mixture and continue stirring to obtain a slurry;

[0111] Sheet the obtained slurry into paper, and after drying, obtain carbon fiber paper;

[0112] Perform high-temperature carbonization treatment on the obtained carbon fiber paper to obtain the base layer;

[0113] Preparation of the microporous layer:

[0114] Mix carbon powder, carbon nanotubes, and polytetrafluoroethylene emulsion together by each weight part to obtain a spraying slurry;

[0115] Spray the obtained spraying slurry evenly on the base layer, and after high-temperature sintering and cooling, form a microporous layer.

[0116] The temperature of the high-temperature carbonization treatment is 550 °C and the time is 40 min;

[0117] The temperature of the high-temperature sintering is 720 °C and the time is 30 min.

[0118] Example 3

[0119] A gas diffusion layer for a hydrogen energy fuel cell, including: a base layer and a microporous layer;

[0120] The thickness of the base layer is 150 μm;

[0121] The thickness of the microporous layer is 50 μm;

[0122] The base layer is made of the following components by weight: 85 parts of modified short carbon fibers, 6 parts of binder, and 2 parts of dispersant;

[0123] The dispersant is a mixture of sodium dodecylbenzenesulfonate and polyacrylic acid;

[0124] Among them, the mass ratio of sodium dodecylbenzenesulfonate to polyacrylic acid is 5:1.

[0125] The microporous layer is made of the following components by weight: 12 parts of carbon powder, 3 parts of carbon nanotubes, and 40 parts of polytetrafluoroethylene emulsion;

[0126] The polytetrafluoroethylene emulsion has a solid content of 60%, a pH of 9.0, and a viscosity of 35 mPa·s.

[0127] The preparation method of the modified short carbon fibers is as follows:

[0128] First, add the short carbon fibers to acetone, soak at room temperature for 30 min, then ultrasonically clean for 20 min, and then filter and dry;

[0129] Add the cleaned short carbon fibers to a concentrated sulfuric acid solution, adjust the temperature to 65 °C, keep warm and stir for 1.5 hours, then filter, wash with water until neutral, and dry to obtain pretreated short carbon fibers;

[0130] Mix the silane coupling agent and ethanol at a volume ratio of 1:10, stir evenly, then add deionized water to make the hydrolysis mass concentration of the silane coupling agent 1.5%, continue to stir for 40 min, and then add maleic anhydride and continue to stir for 30 min to obtain a modified treatment solution;

[0131] Add the pretreated short carbon fibers to the modified treatment solution, adjust the temperature to 52 °C, keep warm and stir for 2 hours, then perform suction filtration, rinse with deionized water for 10 min, and then place in a drying oven and dry for 1 hour;

[0132] Among them, the drying temperature is 108 °C.

[0133] The length of the short carbon fibers is 6 mm;

[0134] The diameter of the short fibers is 7 μm.

[0135] The mixing ratio of the cleaned short carbon fibers to the concentrated sulfuric acid solution is 30 g:120 mL;

[0136] Among them, the mass fraction of concentrated sulfuric acid is 90%.

[0137] The silane coupling agent is KH-550.

[0138] The mass ratio of maleic anhydride to the silane coupling agent is 1:3.

[0139] The mixing ratio of the pretreated chopped carbon fiber and the modification treatment liquid is 25 g: 110 mL.

[0140] The binder is composed of water-based acrylic resin and polyvinyl alcohol;

[0141] A method for preparing a gas diffusion layer for a hydrogen energy fuel cell: includes the following steps:

[0142] Preparation of the base layer:

[0143] Add the modified chopped carbon fiber, binder, and dispersant together by weight to obtain a preliminary mixture, and then add water to the preliminary mixture and continue stirring to obtain a slurry;

[0144] Sheet the obtained slurry into paper, and after drying, obtain carbon fiber paper;

[0145] Subject the obtained carbon fiber paper to high-temperature carbonization treatment to obtain the base layer;

[0146] Preparation of the microporous layer:

[0147] Mix carbon powder, carbon nanotubes, and polytetrafluoroethylene emulsion together by weight to obtain a spraying slurry;

[0148] Spray the obtained spraying slurry evenly on the base layer, and after high-temperature sintering and cooling, form a microporous layer.

[0149] The temperature of the high-temperature carbonization treatment is 550 °C and the time is 40 min;

[0150] The temperature of the high-temperature sintering is 720 °C and the time is 30 min.

[0151] The following are comparative examples:

[0152] Comparative Example 1:

[0153] On the basis of Example 1, no dispersant is added, and the rest of the technical solutions are the same as those of Example 1.

[0154] Comparative Example 2:

[0155] On the basis of Example 1, the chopped fibers are not treated, and the rest of the technical solutions are the same as those of Example 1.

[0156] Test:

[0157] Detect the porosity of the specimens of the examples and comparative examples;

[0158] Table 1

[0159]

[0160]

[0161] As can be seen from Table 1, the gas diffusion layer of the hydrogen energy fuel cell prepared by the present invention has a relatively high porosity.

[0162] The pore size distributions of the specimens of the examples and the comparative examples were detected;

[0163] Table 2

[0164]

[0165] As can be seen from Table 2, the gas diffusion layer prepared by the present invention has a good pore size distribution.

[0166] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A gas diffusion layer for a hydrogen energy fuel cell, characterized in that: include: Base layer and microporous layer; The base layer comprises the following components by weight: 80-85 parts of modified chopped carbon fiber, 4-6 parts of binder, and 1-2 parts of dispersant; The dispersant is a mixture of sodium dodecylbenzoate sulfonate and polyacrylic acid; Wherein, the mixing mass ratio of sodium dodecylbenzoate sulfonate to polyacrylic acid is 5:1; The microporous layer comprises the following ingredients by weight: 10-12 parts of carbon powder, 2-3 parts of carbon nanotubes, and 35-40 parts of polytetrafluoroethylene emulsion; The solid content of the polytetrafluoroethylene emulsion is 60%, the pH is 9.0, and the viscosity is 35 mPa·s.

2. The gas diffusion layer for hydrogen fuel cells according to claim 1, characterized in that: The modified chopped carbon fiber preparation method is: First, the chopped carbon fibers were added to acetone, soaked at room temperature for 30 minutes, then ultrasonically cleaned for 20 minutes, filtered, and dried. The cleaned chopped carbon fibers were added to a concentrated sulfuric acid solution, the temperature was adjusted to 65°C, the solution was stirred for 1.5 hours, filtered, washed with water until neutral, and dried to obtain pretreated chopped carbon fibers; The silane coupling agent and ethanol were mixed in a volume ratio of 1:10, stirred evenly, and then deionized water was added to make the hydrolysis mass concentration of the silane coupling agent 1.2%-1.5%, and the stirring was continued for 40 minutes, and then maleic anhydride was added, and the stirring was continued for 30 minutes to obtain a modified treatment solution; Add the pretreated chopped carbon fiber to the modified treatment solution, adjust the temperature to 52°C, keep warm and stir for 2 hours, then filter, rinse with deionized water for 10 minutes, and then place in a drying oven to dry for 1 hour. The drying temperature is 108°C.

3. The gas diffusion layer for hydrogen fuel cell according to claim 2, characterized in that: The length of the chopped carbon fiber is 6 mm; The chopped fibers had a diameter of 7 μm.

4. The gas diffusion layer for hydrogen fuel cell according to claim 2, characterized in that: The mixed ratio of the cleaned chopped carbon fiber and concentrated sulfuric acid solution is 30 g:120 mL; Among them, the mass fraction of concentrated sulfuric acid is 90%.

5. The gas diffusion layer for hydrogen fuel cell according to claim 2, characterized in that: The silane coupling agent is KH-550.

6. The gas diffusion layer for hydrogen fuel cell according to claim 2, characterized in that: The mass ratio of maleic anhydride to silane coupling agent is 1:

3.

7. The gas diffusion layer for hydrogen fuel cell according to claim 2, characterized in that: The mixing ratio of the pretreated chopped carbon fiber and the modified treatment liquid is 25g:110mL.

8. The gas diffusion layer for hydrogen fuel cell according to claim 1, characterized in that: The adhesive is a mixture of water-based acrylic resin and polyvinyl alcohol.

9. A method for preparing a gas diffusion layer for a hydrogen energy fuel cell according to any one of claims 1 to 8, characterized in that: The following steps are involved: Preparation of base layer: The modified chopped carbon fiber, the binder, and the dispersant are added together in order according to weight to obtain a preliminary mixture, and then water is added to the preliminary mixture, and stirring is continued to obtain a slurry; The obtained slurry is made into paper, and then dried to obtain carbon fiber paper; The obtained carbon fiber paper is subjected to high temperature carbonization treatment to obtain a base layer; Microporous layer preparation: Mixing carbon powder, carbon nanotubes and polytetrafluoroethylene emulsion according to respective weight parts to obtain a spray slurry; The obtained spray slurry is evenly sprayed onto the base layer, sintered at high temperature, and cooled to form a microporous layer.

10. The method for preparing a gas diffusion layer for a hydrogen energy fuel cell according to claim 9, characterized in that: The thickness of the substrate layer is 150 μm; The thickness of the microporous layer is 50 μm; The high temperature carbonization treatment temperature is 550°C and the time is 40 min; The high temperature sintering temperature is 720℃ and the time is 30min.

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