Microporous layer composite powder and its preparation method, microporous layer slurry, gas diffusion layer, fuel cell and electrical equipment

Abstract

This application provides a microporous layer composite powder and its preparation method, a microporous layer slurry, a gas diffusion layer, a fuel cell, and related electrical equipment. The microporous layer composite powder comprises porous carbon and oxygen-rich nanoparticles, wherein the oxygen-rich nanoparticles include aluminosilicates or aluminosilicate oxides; their particle size is 60 nm to 100 nm; their pore size is 0.2 nm to 0.8 nm; and the ratio of the mass fraction of oxygen to the mass fraction of silicon ranges from 0.6 to 1.2. The microporous layer composite powder of this application is beneficial for increasing the oxygen concentration at the interface between the microporous layer and its adjacent layers, enhancing the oxygen mass transfer process, thereby improving the output performance of the fuel cell; at the same time, it can also improve the water retention capacity of the membrane electrode assembly, alleviating the performance degradation caused by membrane drying due to low water content in air-cooled fuel cells, thereby improving the output performance of the fuel cell and the service life of the battery.

Description

Technical Field

[0001] This application belongs to the technical field of fuel cells, and in particular relates to a microporous layer composite powder and its preparation method, a microporous layer slurry, a gas diffusion layer, a fuel cell, and electrical equipment. Background Technology

[0002] Air-cooled fuel cells generate electricity primarily through an electrochemical reaction between hydrogen and air on both sides of the membrane electrode assembly. In addition to generating electricity, water is also produced and waste heat is released. Therefore, maintaining the water-thermal balance in an air-cooled fuel cell helps improve the battery's output performance.

[0003] In related technologies, air-cooled fuel cells, because the cathode is directly connected to the atmosphere and there is no back pressure control, usually require a large amount of air to transfer the heat generated during the power generation process. Therefore, adopting a larger cathode gas metering ratio is beneficial to maintaining the stack temperature and providing sufficient air.

[0004] However, a large flow of dry air can quickly carry the water produced by the reaction to the outside of the fuel cell stack, thereby creating a high-temperature and dry environment inside the fuel cell stack. This high-temperature and dry operating condition seriously affects the performance improvement of air-cooled fuel cells. Summary of the Invention

[0005] This application provides a microporous layer composite powder and its preparation method, a microporous layer slurry, a gas diffusion layer, a fuel cell, and electrical equipment, aiming to solve the technical problem of battery performance degradation caused by high-temperature and dry operating environment in air-cooled fuel cells.

[0006] In a first aspect, embodiments of this application provide a microporous layer composite powder for preparing a fuel cell gas diffusion layer, comprising porous carbon and oxygen-rich nanoparticles, wherein the oxygen-rich nanoparticles are at least attached to the surface of the porous carbon, and the oxygen-rich nanoparticles satisfy the following:

[0007] The oxygen-rich nanoparticles include aluminosilicates or aluminosilicate oxides.

[0008] The oxygen-rich nanoparticles have a particle size of 60 nm to 100 nm.

[0009] The oxygen-rich nanoparticles have a porous structure with a pore size of 0.2 nm to 0.8 nm.

[0010] In the oxygen-rich nanoparticles, the ratio of the mass fraction of oxygen to the mass fraction of silicon ranges from 0.6 to 1.2.

[0011] Optionally, in some embodiments of this application, the oxygen-rich nanoparticles satisfy the following:

[0012] The oxygen-rich nanoparticles have a particle size of 60 nm to 80 nm.

[0013] The oxygen-rich nanoparticles have a porous structure with a pore size of 0.2 nm to 0.6 nm.

[0014] In the oxygen-rich nanoparticles, the ratio of the mass fraction of oxygen to the mass fraction of silicon ranges from 0.6 to 1.

[0015] Optionally, in some embodiments of this application, the oxygen-rich nanoparticles satisfy the following:

[0016] The oxygen-rich nanoparticles have a particle size of 60-80 nm.

[0017] The oxygen-rich nanoparticles have a porous structure with a pore size of 0.4 nm to 0.6 nm.

[0018] In the oxygen-rich nanoparticles, the mass fraction of oxygen and the mass fraction of silicon are 0.6-0.8.

[0019] Secondly, embodiments of this application provide a method for preparing a microporous layer composite powder, comprising:

[0020] A silicon source, an aluminum source, an oxygen source, and a template agent are mixed, pre-crystallized, and crystallized to obtain oxygen-rich nanoparticles. The oxygen-rich nanoparticles have a particle size of 60 nm to 100 nm, a pore size of 0.2 nm to 0.8 nm, and a ratio of the mass fraction of oxygen to the mass fraction of silicon ranging from 0.6 to 1.2.

[0021] The oxygen-rich nanoparticles and porous carbon are combined by dynamic permeation to obtain a microporous layer composite powder, wherein the oxygen-rich nanoparticles are attached to at least the surface of the porous carbon.

[0022] Optionally, in some embodiments of this application, the steps of mixing, pre-crystallizing, and crystallizing the silicon source, aluminum source, oxygen source, and template agent include:

[0023] The silicon source, aluminum source, oxygen source and template agent are mixed and stirred evenly to obtain the first gel;

[0024] The first gel is then pre-crystallized to obtain the second gel;

[0025] The second gel was crystallized and then calcined to obtain the oxygen-rich nanoparticles.

[0026] The molar ratio of the oxygen source to the silicon source ranges from 0.5 to 1.5:1.

[0027] And / or, the pre-crystallization temperature is 80°C to 100°C, and the time is 6h to 12h;

[0028] And / or, the crystallization temperature is 120°C to 180°C, and the time is 24h to 72h;

[0029] And / or, the crystallization pressure is from 0.5 MPa to 2 MPa;

[0030] And / or, the concentration of the template agent is from 0.05 mol / L to 0.55 mol / L.

[0031] Optionally, in some embodiments of this application, the silicon source includes at least one selected from silica sol, sodium silicate solution, silicic acid solution, and methyltriethoxysilane; and / or

[0032] The aluminum source includes at least one of aluminum isopropoxide, aluminum nitrate, aluminum sulfate, and aluminum chloride; and / or

[0033] The oxygen source includes hydrogen peroxide; and / or

[0034] The template agent includes at least one of tetrapropylammonium hydroxide and hexadecyltrimethylammonium bromide.

[0035] Optionally, in some embodiments of this application, the molar ratio of the oxygen source to the silicon source ranges from 0.5 to 1.5:1; and / or

[0036] The molar ratio of the silicon source to the aluminum source ranges from 30 to 50:1; and / or

[0037] The molar ratio of the template agent to the silicon source ranges from 0.2 to 0.4:1.

[0038] Optionally, in some embodiments of this application, the step of combining the oxygen-rich nanoparticles and porous carbon via a dynamic permeation method includes:

[0039] The oxygen-rich nanoparticles were stirred and uniformly infiltrated into the porous carbon to obtain a wet gel.

[0040] The wet gel is dried by gradually increasing the temperature at a preset temperature;

[0041] The stirring speed is 500-1500 rpm / min, and the stirring time is 1 to 4 hours; and / or

[0042] The preset temperature is 60°C to 110°C.

[0043] Thirdly, embodiments of this application provide a microporous layer slurry, comprising a solvent, additives, and the aforementioned microporous layer composite powder; or comprising a solvent, additives, and microporous layer composite powder prepared by the aforementioned preparation method.

[0044] Fourthly, embodiments of this application provide a gas diffusion layer comprising a substrate layer and a microporous layer coated on the substrate layer, the microporous layer being formed by coating the substrate layer with a microporous layer slurry as described above.

[0045] Fifthly, embodiments of this application provide a fuel cell, the fuel cell including the gas diffusion layer as described above.

[0046] Sixthly, embodiments of this application provide an electrical device, which includes a fuel cell as described above. The type of electrical device is not limited; it can be an automobile, ship, drone, stationary power source, portable power source, etc.

[0047] The beneficial effects of the embodiments of this application are as follows:

[0048] This application presents a microporous layer composite powder by combining porous carbon and oxygen-enriched nanoparticles, and controlling the particle size, pore size, and oxygen-silica ratio of the oxygen-enriched nanoparticles. A specific particle size (60 nm to 100 nm) ensures good dispersibility of the prepared aluminosilicate or aluminosilicate oxide particles on the surface of the microporous layer composite powder, resulting in a suitable carbon surface coverage. A pore size of 0.2-0.8 nm directly affects the oxygen-enriching effect of the prepared aluminosilicate particles, promoting the passage of oxygen molecules while blocking nitrogen molecules, thus achieving oxygen enrichment. Furthermore, an oxygen-silica ratio range of 0.6-1.2 endows the aluminosilicate with hydrophilic properties. Water generated through hydrogen bonding adsorption reactions helps improve the water retention capacity of the membrane electrode assembly, thereby alleviating the performance degradation problem of air-cooled fuel cells caused by high-temperature and dry operating environments, and also contributing to extending the service life of air-cooled fuel cells.

[0049] The preparation method of the microporous layer composite powder of this application prepares oxygen-rich nanoparticles through a two-stage crystallization method, and combines the oxygen-rich nanoparticles and porous carbon into a microporous layer composite powder through a dynamic infiltration method. The two-stage crystallization method can more accurately control parameters such as particle size, pore size, and oxygen-silicon ratio of oxygen-rich nanoparticles through segmented control process. The dynamic infiltration method promotes higher dispersion uniformity and interfacial bonding force of composite material by fully mixing and gradient heating, thereby improving the electrochemical performance of microporous layer composite powder.

[0050] The microporous layer slurry, gas diffusion layer, fuel cell, and electrical equipment of this application all adopt the above-mentioned microporous layer composite powder, which helps to increase the oxygen concentration at the interface between the cathode catalyst layer and the microporous layer, enhance the oxygen mass transfer process, and thus improve the output performance of the fuel cell. In addition, the increase in oxygen concentration can alleviate the performance degradation caused by changes in cathode metering ratio, and at the same time help to extend the service life of air-cooled fuel cells. Attached Figure Description

[0051] To more clearly illustrate the solutions in this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0052] Figure 1 Here are scanning electron microscope images of microporous layer composite powders in some embodiments of this application;

[0053] Figure 2 This is an elemental distribution diagram of the microporous layer composite powder in some embodiments of this application;

[0054] Figure 3 This is a flowchart illustrating the preparation method of microporous layer composite powder in some embodiments of this application;

[0055] Figure 4 Here are scanning electron microscope (SEM) images of the microporous layer in some embodiments of this application;

[0056] Figure 5 This is a schematic diagram of the gas diffusion layer in a fuel cell in some embodiments of this application;

[0057] Figure 6 This is a comparison chart of the output performance of fuel cells according to some embodiments of this application;

[0058] In the picture,

[0059] 100. Cathode substrate layer; 200. Cathode microporous layer; 300. Cathode catalyst layer; 400. Proton exchange membrane; 500. Anode catalyst layer; 600. Anode microporous layer; 700. Anode substrate layer; 800. Fuel cell anode composition; 900. Fuel cell cathode composition. Detailed Implementation

[0060] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. In addition, it should be understood that the specific embodiments described herein are only for illustration and explanation of this application and are not intended to limit this application. In this application, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0061] To address the technical problem of performance degradation in air-cooled fuel cells due to membrane drying caused by high-temperature and dry environments, this application provides a microporous layer composite powder for preparing a fuel cell gas diffusion layer. The powder comprises porous carbon and oxygen-rich nanoparticles, wherein the oxygen-rich nanoparticles are at least attached to the surface of the porous carbon, and the oxygen-rich nanoparticles satisfy the following conditions:

[0062] Oxygen-rich nanoparticles include aluminosilicates or aluminosilicate oxides;

[0063] The particle size of the oxygen-enriched nanoparticles ranges from 60 nm to 100 nm.

[0064] Oxygen-rich nanoparticles have a porous structure with pore sizes ranging from 0.2 nm to 0.8 nm.

[0065] In oxygen-enriched nanoparticles, the ratio of the mass fraction of oxygen to the mass fraction of silicon ranges from 0.6 to 1.2.

[0066] By adopting the above-mentioned scheme, the microporous layer composite powder of this application embodiment includes porous carbon and oxygen-enriched nanoparticles. The oxygen-enriched nanoparticles include aluminosilicates or aluminosilicate oxides. Moreover, the particle size and pore size of these oxygen-enriched nanoparticles are limited to the aforementioned range, which is beneficial to increase the oxygen concentration at the interface between the microporous layer and its adjacent layers, enhance the oxygen mass transfer process, and thus improve the output performance of the fuel cell. At the same time, the mass fraction of oxygen and silicon elements in the oxygen-enriched nanoparticles is within the aforementioned range, which can also improve the water retention capacity of the membrane electrode, alleviate the performance degradation caused by membrane drying due to low water content in air-cooled fuel cells, and thus improve the output performance of the fuel cell and the service life of the battery.

[0067] In one embodiment, the oxygen-rich nanoparticles satisfy the following:

[0068] The particle size of the oxygen-enriched nanoparticles is 60 nm to 80 nm.

[0069] Oxygen-rich nanoparticles have a porous structure with pore sizes ranging from 0.2 nm to 0.6 nm.

[0070] In oxygen-enriched nanoparticles, the ratio of the mass fraction of oxygen to the mass fraction of silicon ranges from 0.6 to 1.

[0071] By adopting the above approach, it is helpful to further enhance the oxygen-enriching capacity and hydrophilic properties of oxygen-enriched nanoparticles, thereby further improving the output performance of fuel cells.

[0072] In one embodiment, the oxygen-rich nanoparticles satisfy the following:

[0073] The particle size of the oxygen-enriched nanoparticles is 60-80 nm;

[0074] Oxygen-rich nanoparticles have a porous structure with a pore size of 0.4 nm to 0.6 nm.

[0075] In oxygen-enriched nanoparticles, the mass fractions of oxygen and silicon are 0.6-0.8.

[0076] By adopting the above approach, it is possible to further enhance the oxygen-enriching capacity and hydrophilic properties of oxygen-enriched nanoparticles, thereby further improving the output performance of fuel cells.

[0077] According to a second aspect of the embodiments of this application, a method for preparing a microporous layer composite powder is provided, the method comprising the following steps:

[0078] S100. A silicon source, an aluminum source, an oxygen source and a template agent are mixed, pre-crystallized and crystallized to obtain oxygen-rich nanoparticles. The particle size of the oxygen-rich nanoparticles is 60 nm to 100 nm, the pore size is 0.2 nm to 0.8 nm, and the ratio of the mass fraction of oxygen to the mass fraction of silicon is 0.6 to 1.2.

[0079] S200. Oxygen-rich nanoparticles and porous carbon are combined by dynamic permeation to obtain microporous composite powder, wherein the oxygen-rich nanoparticles are at least attached to the surface of the porous carbon.

[0080] By adopting the above scheme, using dynamic infiltration to combine oxygen-rich nanoparticles with porous carbon, and applying this composite powder to the gas diffusion layer, it is beneficial to improve the structural stability of the composite powder and enhance the dispersibility of the subsequent slurry, which is conducive to mass production and coating.

[0081] In one embodiment, please refer to Figure 3 The steps of mixing, pre-crystallizing, and crystallizing the silicon source, aluminum source, oxygen source, and template agent include:

[0082] S110. Mix the silicon source, aluminum source, oxygen source and template agent, stir evenly to obtain the first gel;

[0083] S120, and then the first gel is pre-crystallized to obtain the second gel;

[0084] S130. The second gel is crystallized and then calcined to obtain oxygen-rich nanoparticles.

[0085] In one embodiment, in step S110, the silicon source may include at least one of silica sol, sodium silicate solution, silicic acid solution, and methyltriethoxysilane. Exemplarily, the main component of silica sol is silicon dioxide.

[0086] In one embodiment, the mass concentration of the silica sol can range from 25% to 35%. Exemplarily, the mass concentration of the silica sol can be 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, or any value between two adjacent values.

[0087] In one embodiment, in step S110, the aluminum source may include at least one of aluminum isopropoxide, aluminum nitrate, aluminum sulfate, and aluminum chloride. For example, the chemical formula of aluminum nitrate may be Al(NO3)3·9H2O.

[0088] In one embodiment, in step S110, the oxygen source may include hydrogen peroxide. Exemplarily, hydrogen peroxide may be added in solution form.

[0089] In one embodiment, the concentration of the hydrogen peroxide solution ranges from 12% to 20%. Exemplarily, the concentration of the hydrogen peroxide solution can be 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, or any value between two adjacent values.

[0090] In one embodiment, in step S110, the template agent may include at least one of tetrapropylammonium hydroxide and hexadecyltrimethylammonium bromide.

[0091] In some embodiments of this application, the concentration of the template agent ranges from 0.05 mol / L to 0.55 mol / L. Exemplarily, the concentration of the template agent can be 0.05 mol / L, 0.1 mol / L, 0.15 mol / L, 0.2 mol / L, 0.25 mol / L, 0.3 mol / L, 0.35 mol / L, 0.4 mol / L, 0.45 mol / L, 0.5 mol / L, 0.55 mol / L, or any value between two adjacent values.

[0092] It should be noted that the higher the concentration of the template agent, the more beneficial it is to promoting the increase in the particle size of oxygen-enriched nanoparticles. For example, for every 0.1 mol / L increase in the concentration of the template agent, the particle size of the oxygen-enriched nanoparticles can increase by 20 nm.

[0093] In one embodiment, step S120, pre-crystallization includes the following steps:

[0094] 30 wt% silica sol and template agent were mixed in deionized water and ultrasonically dispersed for 30 minutes to obtain the first mixed solution;

[0095] Add ammonia water dropwise to the first mixed solution to adjust the pH to 9-10, then add the aluminum source solution dropwise and mix thoroughly to obtain the second mixed solution;

[0096] Hydrogen peroxide solution was added to the second mixed solution and magnetically stirred at a speed of 50-300 rpm for 1-3 hours. The specific stirring process was as follows: the initial speed was 300 rpm to promote mixing, the middle speed was 150 rpm to reduce shear force, and the later speed was 50 rpm to allow the crystal nuclei to assemble in an orderly manner, thus obtaining the first gel.

[0097] The first gel was then transferred to a hydrothermal reactor for high-temperature pre-crystallization for 6 to 12 hours, with the reaction temperature ranging from 80°C to 100°C. Specifically, the temperature was increased in increments of 20°C for 2 hours each, to obtain the second gel.

[0098] Specifically, by increasing the temperature gradient, the dispersion of the crystal nucleus size can be reduced, thereby controlling the crystal nucleus size within ±5nm.

[0099] In one embodiment, the molar ratio of silicon source to aluminum source ranges from 30 to 50:1. Exemplarily, the molar ratio of silicon source to aluminum source can be 30:1, 32:1, 35:1, 38:1, 40:1, 42:1, 45:1, 47:1, 50:1, or any ratio between any two of the above ratios.

[0100] In one embodiment, the molar ratio of oxygen source to silicon source ranges from 0.5 to 1.5:1. Exemplarily, the molar ratio of oxygen source to silicon source can be 0.5:1, 0.75:1, 0.9:1, 1.1:1, 1.3:1, 1.5:1, or any ratio between any two of the above.

[0101] In one embodiment, the molar ratio of the template agent to the silicon source ranges from 0.2 to 0.4:1. Exemplarily, the molar ratio of the template agent to the silicon source can be 0.2:1, 0.25:1, 0.3:1, 0.35:1, 0.4:1, or any ratio between any two of the above.

[0102] In one embodiment, step S130, the crystallization process includes the following steps:

[0103] Ammonia solution was added to the second gel to adjust the pH to 8-9, and a second hydrothermal crystallization was carried out. The gel was heated at 120℃ to 180℃ using a gradient heating method for 24h to 72h and at a pressure of 0.5MPa to 2MPa to obtain aluminosilicate sol.

[0104] The aluminosilicate sol was centrifuged at 3000 rpm to 5000 rpm for 5 to 15 minutes, then washed with ethanol to remove the raw materials and impurities of the reaction, and then repeatedly washed with deionized water to remove the mother liquor. Finally, it was dried and calcined at 500℃ to 600℃ for 2 to 6 hours to obtain oxygen-enriched nanoparticles.

[0105] It should be noted that after adding ammonia solution to the second gel, a gradient heating method is used, and the average pore size of the aluminosilicate can be increased by 0.3 to 0.5 nm for every 20°C increase.

[0106] In one embodiment, the heating time is 24h, 32h, 38h, 40h, 43h, 45h, 48h, 51h, 55h, 58h, 62h, 65h, 68h, 70h, 72h, and any value between two adjacent values ​​mentioned above.

[0107] In one embodiment, the pressure can be 0.5 MPa, 0.75 MPa, 0.9 MPa, 1.1 MPa, 1.3 MPa, 1.6 MPa, 2 MPa, or any value between any two adjacent values ​​mentioned above.

[0108] In one embodiment, the heating rate of the gradient heating is in the range of 0.5 °C / min to 5 °C / min. For example, for every 1 °C / min decrease in the heating rate, the average pore size of the porous carbon increases by 0.4 nm.

[0109] In one embodiment, the D50 particle size of the porous carbon is from 0.8 μm to 2.8 μm. Exemplarily, the D50 particle size of the porous carbon can be 0.8 μm, 1.0 μm, 1.2 μm, 1.5 μm, up to 2.8 μm, and any value between two adjacent values.

[0110] In one embodiment, the D90 particle size of the porous carbon is from 1.5 μm to 6.5 μm. Exemplarily, the D90 particle size of the porous carbon can be 1.5 μm, 2.0 μm, 2.5 μm, 3.0 μm, 3.5 μm, 4.0 μm, 4.5 μm, 5.0 μm, 5.5 μm, 6.0 μm, 6.5 μm, and any value between two adjacent values.

[0111] In one embodiment, the d of porous carbon 002 The value ranges from 0.3354 to 0.3440, indicating that porous carbon has a certain degree of graphitization.

[0112] It is understandable that porous carbon has a particle size in the micrometer range, while oxygen-enriched nanoparticles have a particle size in the nanometer range. Porous carbon and oxygen-enriched nanoparticles can form a bimodal pore size distribution. Macropores help to conduct water, while micropores help to enrich oxygen, thus solving the problem of air-cooled fuel cells having both drainage and moisture retention functions.

[0113] In one embodiment, the loose packing density of the porous carbon can range from 0.8 g / ml to 1.5 g / ml. Exemplarily, the loose packing density of the porous carbon can be 0.8 g / ml, 0.9 g / ml, 1.0 g / ml, 1.1 g / ml, 1.2 g / ml, 1.3 g / ml, 1.4 g / ml, 1.5 g / ml, or any value between two adjacent values.

[0114] In one embodiment, the specific surface area of ​​the porous carbon ranges from 100 m². 2 / g to 200m 2 / g. For example, the specific surface area of ​​porous carbon can be 100 m². 2 / g、110m 2 / g, 120m 2 / g, 130m 2 / g, 140m 2 / g, 150m 2 / g, 160m 2 / g、170m 2 / g、180m 2 / g、190m 2 / g、200m 2 / g and any value between the two adjacent values ​​mentioned above.

[0115] In one embodiment, the porous carbon can also be pretreated to help increase the functional groups on the surface of the porous carbon, thereby improving the binding force between the porous carbon and oxygen-rich nanoparticles.

[0116] In one embodiment, the pretreatment process of porous carbon includes the following steps: placing the porous carbon in a mixed acid solution of HNO3 / H2SO4 for acidification / oxidation treatment, which is beneficial to increase functional groups such as carboxyl groups and hydroxyl groups on the surface of the porous carbon.

[0117] In one embodiment, the dynamic permeation method may employ stirring, which helps to promote the uniform permeation of porous carbon and oxygen-rich nanoparticles.

[0118] In one embodiment, the dynamic permeation time ranges from 1 hour to 4 hours, and a suitable time helps to reduce excessive deposition of molecular sieves.

[0119] In one embodiment, the drying process can employ a gradient temperature increase, with the temperature gradient being 60°C, 80°C, or 110°C, to avoid situations such as pore collapse caused by high temperature or rapid drying.

[0120] Understandably, the preparation method of the microporous layer composite powder material adopts the above steps, which helps to retain the regular channels of oxygen-rich nanoparticles and the microporous / mesoporous structure of porous carbon.

[0121] In one embodiment, the carbon can be subjected to high-temperature heat treatment after drying, which helps to enhance the electrical conductivity of the porous carbon and the thermal stability of the oxygen-rich nanoparticles.

[0122] For example, the high-temperature heat treatment process includes the following steps: heat treatment is performed in an inert atmosphere at a high temperature of 300°C to 500°C.

[0123] In one embodiment, the coverage rate of oxygen-enriched nanoparticles in the microporous layer composite powder ranges from 70% to 90%. Exemplarily, the coverage rate of oxygen-enriched nanoparticles in the microporous layer composite powder can be 70%, 72%, 75%, 78%, 80%, 82%, 85%, 88%, 90%, or any value between two adjacent values. A higher coverage rate of oxygen-enriched nanoparticles in the microporous layer composite powder is more beneficial for enhancing the oxygen mass transfer process in the microporous layer, thereby improving the output performance of the fuel cell.

[0124] This application also provides a microporous layer slurry, comprising a solvent, additives, and the aforementioned microporous layer composite powder; or comprising a solvent, additives, and a microporous layer composite powder prepared by the aforementioned preparation method.

[0125] In one embodiment, the solvent may include water.

[0126] In one embodiment, the additive may include a surfactant. Exemplarily, the surfactant may be polyvinylpyrrolidone.

[0127] This application also provides a gas diffusion layer comprising a substrate layer and a microporous layer coated on the substrate layer, the microporous layer being formed by coating the substrate layer with a microporous layer slurry as described above.

[0128] By adopting the above scheme, the interfacial oxygen concentration in the microporous layer of the gas diffusion layer can be increased, enhancing the oxygen mass transfer process and thus improving the output performance of the fuel cell. Furthermore, the increased oxygen concentration can alleviate performance fluctuations caused by changes in the cathode stoichiometry and improve the stability of the fuel cell output voltage.

[0129] For example, refer to Figure 5 The gas diffusion layer includes a cathode assembly 800 and an anode assembly 900. The cathode assembly 800 includes a cathode substrate layer 100, a cathode microporous layer 200, a cathode catalyst layer 300, and a proton exchange membrane 400 stacked sequentially. The anode assembly 900 includes an anode substrate layer 700, an anode microporous layer 600, and an anode catalyst layer 500 stacked sequentially; the anode catalyst layer 500 is connected to the proton exchange membrane 400.

[0130] This application also provides a fuel cell that includes a gas diffusion layer as described above.

[0131] By adopting the above approach, it is possible to improve the output performance and lifespan of fuel cells.

[0132] This application also provides an electrical device, which includes a gas diffusion layer as described above or a fuel cell as described above.

[0133] By adopting the above solutions, it is helpful to improve the battery life and service life of electrical equipment.

[0134] The present application will be further described below through specific embodiments. Unless otherwise specified, the experimental materials used in the embodiments can be purchased from conventional biochemical reagent companies.

[0135] Example 1

[0136] A gas diffusion layer is prepared by the following steps:

[0137] (I) Preparation of oxygen-enriched nanoparticles:

[0138] 1. Precrystallization process:

[0139] Ten parts of 30 wt% silica sol and four parts of 0.25 mol / L template agent hexadecyl trimethyl ammonium bromide (CATB) were mixed in ten parts of deionized water and ultrasonically dispersed for 30 minutes to obtain the first mixed solution.

[0140] Add an appropriate amount of 10wt% ammonia water to the first mixed solution to adjust the pH to 9.5, then add 0.4 parts of 10% aluminum nitrate solution and mix well to obtain the second mixed solution;

[0141] Eight parts of 15wt% hydrogen peroxide solution were added to the second mixed solution and magnetically stirred at a speed of 50-300 rpm for 1-3 hours. Specifically, the stirring process was as follows: 300 rpm for the first 0.5 hours, 150 rpm for the middle 1 hour, and 50 rpm for the last 0.5 hours to obtain the first gel.

[0142] The first gel was then transferred to a hydrothermal reactor for high-temperature pre-crystallization for 6 hours. The reaction temperature was 80℃~100℃, with the temperature increased in increments of 20℃ for 2 hours per increment. After cooling, the second gel was obtained.

[0143] 2. Crystallization process:

[0144] Ammonia solution was added to the second gel to adjust the pH to 8.5, and a second hydrothermal crystallization was carried out. The gel was heated in a 20°C gradient from 120°C to 160°C, with each gradient heating time being 8 hours and the constant temperature pressure being 1.5 MPa. After heating, the gel was allowed to cool naturally to obtain aluminosilicate sol.

[0145] The aluminosilicate sol was centrifuged at 3000 rpm for 10 min, then washed with ethanol to remove the raw materials and impurities of the reaction, and then repeatedly washed with deionized water to remove the mother liquor. Finally, it was dried and calcined at 550℃ for 4 h with a calcination heating rate of 5℃ / min to obtain oxygen-enriched nanoparticles.

[0146] (II) Preparation of microporous layer composite powder:

[0147] 1. Porous carbon pretreatment:

[0148] Porous carbon was subjected to acidification / oxidation treatment in a mixed acid solution of HNO3 / H2SO4. The D50 particle size of the porous carbon was 0.8 μm to 2.8 μm, the D90 particle size was 1.5 μm to 6.5 μm, and the d... 002 Its molecular weight is 0.3354~0.3440, its loose bulk density is 0.8-1.5 g / ml, and its specific surface area is 50-200 m². 2 / g;

[0149] 2. Dispersion of oxygen-enriched nanoparticles:

[0150] The oxygen-rich nanoparticles prepared in step (I) were dispersed in 100 mL of deionized water, and 0.5 wt% of polyvinylpyrrolidone was added. The mixture was then dispersed under ultrasonication for 30 min to form a uniform suspension.

[0151] 3. Preparation of microporous layer composite powder:

[0152] 30 parts of pretreated porous carbon were slowly added to 10 parts of suspension and ultrasonically dispersed for 10 minutes to obtain a mixture.

[0153] The mixture was transferred to a permeation tank and treated by dynamic permeation (stirring) for 2 hours to obtain a mixed gel.

[0154] The mixed gel was then placed in an oven and dried at a gradient temperature of 60°C to 110°C for 12 hours. Finally, it was heat-treated at 300°C under a N2 atmosphere to obtain the microporous layer composite powder.

[0155] (III) Preparation of microporous layer slurry:

[0156] 1. Prepare the ingredients according to the following proportions by weight:

[0157] 100 parts water, 9 parts microporous layer composite powder material, 0.9 parts betaine-type amphoteric surfactant, 0.9 parts pore-forming agent polyethylene glycol, and 0.09 parts defoamer polydimethylsiloxane;

[0158] 2. Preparation of slurry:

[0159] The above components were added to water and mixed using a polytetrafluoroethylene stirring paddle at a stirring speed of 1000 rpm / min for 2 hours to obtain a primary slurry.

[0160] The primary slurry was stirred at high speed (10,000 rpm) for 15 minutes to obtain the secondary slurry.

[0161] Add 0.45 parts of thickener hydroxypropyl methylcellulose and 0.18 parts of 60 wt.% PTFE to the second slurry, continue stirring at a stirring speed of 1000 rpm for 2 hours to obtain a microporous layer slurry.

[0162] (iv) Preparation of the gas diffusion layer:

[0163] 1. Hydrophobic treatment of the carbon paper substrate layer:

[0164] The carbon paper was washed in a 1:1 volume ratio ethanol-acetone mixture and then air-dried to obtain the washed carbon paper.

[0165] The dried carbon paper is immersed in a PTFE solution with a pH of 7 to 7.5 and a PTFE concentration of 5% to 10%. The immersion is repeated multiple times and then dried. Finally, it is cured at a high temperature of 300°C to obtain a hydrophobic carbon paper substrate layer.

[0166] 2. Preparation of the gas diffusion layer:

[0167] The above-mentioned microporous slurry was coated onto the surface of a hydrophobically treated carbon paper substrate, and then dried and calcined to obtain a gas diffusion layer; wherein the drying temperature was 110℃ and the time was 0.5h, the calcination temperature was 300℃ and the time was 2h, and the heating rate was 1~10℃ / min.

[0168] Example 2

[0169] The difference between Example 2 and Example 1 is that the secondary hydrothermal crystallization is carried out at 120°C to 140°C, while the rest is the same as in Example 1.

[0170] Example 3

[0171] The difference between Example 3 and Example 2 is that the CATB template agent added is 0.15 mol / L; the amount of 15 wt% hydrogen peroxide solution added is 6 parts; the secondary hydrothermal crystallization is carried out at a temperature of 120°C to 150°C using a 10°C gradient heating method, and the rest is the same as Example 2.

[0172] Example 4

[0173] The difference between Example 4 and Example 2 is that the amount of 15wt% hydrogen peroxide solution added is 6 parts, and the rest is the same as in Example 2.

[0174] Example 5

[0175] The difference between Example 5 and Example 3 is that the secondary hydrothermal crystallization was carried out at a temperature of 120°C for 24 hours, while the rest was the same as in Example 3.

[0176] Example 6

[0177] The difference between Example 6 and Example 1 is that the amount of 15wt% hydrogen peroxide solution added is 10 parts, and the rest is the same as in Example 1.

[0178] Example 7

[0179] The difference between Example 7 and Example 1 is that the amount of 15wt% hydrogen peroxide solution added is 12 parts, and the rest is the same as in Example 1.

[0180] Example 8

[0181] The difference between Example 8 and Example 1 is that the secondary hydrothermal crystallization is carried out at 120°C to 180°C; finally, the product is dried and calcined at a heating rate of 4°C / min, while the rest is the same as in Example 1.

[0182] Example 9

[0183] The difference between Example 9 and Example 1 is that the CATB template agent added is 0.30 mol / L, and the rest is the same as Example 1.

[0184] Comparative Example 1

[0185] The difference between Comparative Example 1 and Example 1 is that the particle size of the oxygen-rich nanoparticles is different, the CATB template agent added is 0.35 mol / L, and the isothermal pressure during the secondary crystallization process is 2.0 MPa. The rest is the same as Example 1.

[0186] Comparative Example 2

[0187] The difference between Comparative Example 2 and Example 1 is that the particle size of the oxygen-rich nanoparticles is different, the CATB template agent added is 0.40 mol / L, and the isothermal pressure during the secondary crystallization process is 2.0 MPa. The rest is the same as Example 1.

[0188] Comparative Example 3

[0189] The difference between Comparative Example 3 and Example 1 is that the pore size of the oxygen-rich nanoparticles is different, and the secondary hydrothermal crystallization is carried out at 120°C to 180°C; finally, it is dried and calcined at a calcination heating rate of 4°C / min, and the rest is the same as Example 1.

[0190] Comparative Example 4

[0191] The difference between Comparative Example 4 and Example 1 is that the pore size of the oxygen-rich nanoparticles is different, and the secondary hydrothermal crystallization is carried out at 120°C to 180°C; finally, it is dried and calcined at a calcination heating rate of 3°C / min, and the rest is the same as Example 1.

[0192] Comparative Example 5

[0193] The difference between Comparative Example 5 and Example 1 lies in the composite method of oxygen-rich nanoparticles and porous carbon. In Comparative Example 5, the oxygen-rich nanoparticle powder material prepared in step (I) was dispersed in 100 mL of deionized water to form a uniform dispersion. 30 parts of the pretreated microporous layer composite powder were slowly added to 10 parts of the dispersion and ultrasonically dispersed for 10 min to obtain a mixture. The mixture was then placed in an oven and dried at a gradient temperature between 60°C and 110°C for 12 h. Finally, it was heat-treated at 300°C under a N2 atmosphere to obtain the microporous layer composite powder material. The rest was the same as in Example 1.

[0194] Comparative Example 6

[0195] The difference between Comparative Example 6 and Example 1 lies in the composite method of oxygen-enriched nanoparticles and porous carbon. In Comparative Example 6, 30 parts of pretreated microporous layer composite powder and 10 parts of oxygen-enriched nanoparticles were added to a mixing container and stirred at a speed of 3000 rpm for 2 hours. The mixed powder was then placed in an oven and dried at a gradient temperature between 60°C and 110°C for 12 hours. Finally, it was heat-treated at 300°C under a N2 atmosphere to obtain the microporous layer composite powder material. The rest was the same as in Example 1.

[0196] Comparative Example 7

[0197] The difference between Comparative Example 7 and Example 1 lies in the coating method. In the preparation of the gas diffusion layer, the microporous composite powder was prepared as a slurry and coated onto the surface of the hydrophobically treated carbon paper substrate. After drying and calcination, oxygen-rich nanoparticles were then prepared as a slurry and coated onto the surface of the hydrophobically treated carbon paper substrate. The drying and calcination were then continued. The drying and calcination temperatures and times were the same as in Example 1. The rest was the same as in Example 1.

[0198] Test methods

[0199] (I) Material Testing Methods

[0200] The method for determining the silicon-to-oxygen ratio involves separately measuring the Si and O contents in the sample. O elemental analysis follows the method recommended in GB / T 11261-2006; Si elemental analysis follows the method recommended in GB / T 38823-2020. The relevant particle size analysis method follows the method recommended in GB / T 19077-2016. The average pore size analysis method follows the method recommended in GB / T 21650.3-2011.

[0201] (II) Test methods for gas diffusion layers

[0202] 1. Single-cell testing: The testing process includes membrane electrode activation and polarization curve testing. Activation steps include purging, heating, humidification, and loading. After membrane electrode assembly, nitrogen purging is used to remove impurities from the battery, followed by hydrogen-nitrogen purging to improve the hydrogen-air interface. Finally, hydrogen-air purging is used until the open-circuit voltage stabilizes. During purging, the battery temperature and dew point temperature are both set to 60℃, the anode and cathode back pressures are 50kPa, the gas metering ratio is 1.2:4.5, and the current is increased until the voltage is approximately 0.5V. Once the internal resistance reaches its minimum, the humidification tank temperature control is turned off, allowing it to cool naturally while the battery humidity gradually decreases. The voltage and temperature are maintained for 4 hours until activation is complete. In the testing phase, the battery temperature is set to 60℃, the dew point temperature to 25℃, the anode back pressure to 50kPa, and the cathode back pressures to 0kPa and 10kPa, respectively. The gas metering ratio was 1.2:4.5 to simulate the actual operation of an air-cooled reactor. Two planned curves were tested under two different cathode back pressures, with the test current range being 0–1.5 A / cm. 2 .

[0203] 2. Air-cooled fuel cell stack testing:

[0204] After the fuel cell stack is assembled, hydrogen is introduced. The hydrogen venting cycle is set to 0.5s:3s. The fan is turned on, and the automatic current loading is set to start the test. During the test, the fan is adjusted to ensure that the battery temperature does not exceed 60℃. The test range is 0-1.5A / cm. 2 Polarization curve.

[0205] The test results are shown in Table 1.

[0206]

[0207]

[0208] Comparing Examples 1-9 with Comparative Examples 1-7 reveals that when the oxygen-rich nanoparticles are controlled to meet the following conditions (i.e., particle size between 60 nm and 100 nm, pore size between 0.2 nm and 0.8 nm, and the ratio of oxygen mass fraction to silicon mass fraction between 0.6 and 1.2), the fuel cell can achieve a power output of 0.5 A / cm². 2 When it reaches above 0.74, at 1.0 A / cm 2 It remained above 0.66 at 1.5 A / cm 2 The oxygen-silicon ratio remains above 0.63, which is considered optimal battery performance. However, when this condition is not met, battery performance deteriorates. This may be because oxygen-enriched nanoparticles within a certain size range exhibit good dispersibility on the surface of the microporous composite powder. Excessively large particle sizes reduce the number of effective pores, thus decreasing oxygen-enriching capacity. Furthermore, excessively large particles have reduced adhesion to carbon material surfaces and are prone to detachment. Pore size distribution directly affects the oxygen-enriching effect of oxygen-enriched nanoparticles. Small pores prevent oxygen from easily passing through and reaching the membrane electrode surface to participate in the reaction, while excessively large pores allow both nitrogen and oxygen from the air to pass through, hindering effective oxygen enrichment. A certain range of oxygen / silicon ratio is crucial. An oxygen / silicon ratio ≤1.2 prevents structural collapse, while an excessively low ratio weakens oxygen doping, preventing the formation of a stable aluminosilicate structure. Therefore, a ratio between 0.6 and 1.2 achieves optimal electrochemical performance.

[0209] A comparison of Examples 1-5 and Examples 6-8 reveals that when the oxygen-rich nanoparticles are further controlled to meet the conditions of "particle size between 60 nm and 80 nm, pore size between 0.2 nm and 0.6 nm, and the ratio of oxygen mass fraction to silicon mass fraction between 0.6 and 1" (i.e., Examples 1-5), the fuel cell can achieve a speed of 0.5 A / cm². 2 When it reaches above 0.745, at 1.0 A / cm 2 It remained above 0.67 at 1.5 A / cm 2 The pH value remained above 0.63, indicating better battery performance. This is likely because the smaller particle size promotes better dispersion of oxygen-enriched nanoparticles on the surface of the microporous composite powder, while the smaller pore size facilitates oxygen passage, further enhancing the oxygen-enriching effect and thus improving battery performance.

[0210] Comparing Examples 1-2 and Examples 3-5 reveals that when the oxygen-rich nanoparticles are further controlled to meet the conditions of "particle size of 60-80 nm, pore size between 0.4 nm and 0.6 nm, and a mass fraction ratio of oxygen to silicon of 0.6-0.8" (i.e., Examples 1-2), the fuel cell can achieve a speed of 1.0 A / cm². 2The battery performance remains above 0.7 with an internal resistance of less than 2, indicating optimal battery performance. This is likely because further reducing the pore size allows for better confinement of oxygen passing through the oxygen-rich nanoparticles, further enhancing performance. When the oxygen-to-silicon ratio is between 0.6 and 0.8, oxygen doping makes the silicon-oxygen particles in the oxygen-rich nanoparticles most stable, resulting in the best battery performance.

[0211] Comparing Example 1 and Comparative Examples 5-7 reveals that when porous carbon and oxygen-rich nanoparticles are not combined using the dynamic permeation method, even when the oxygen-rich nanoparticles meet the conditions of "particle size between 60 nm and 100 nm, pore size between 0.2 nm and 0.8 nm, and the ratio of oxygen mass fraction to silicon mass fraction between 0.6 and 1.2," the battery performance is still poor. This is because the dynamic dispersion method provides better dispersion uniformity. Compared to dry mixing, it better ensures the structural integrity of the oxygen-rich nanomaterials; compared to wet mixing, the interfacial bonding is stronger, and the oxygen-rich nanoparticles are loaded onto the carbon powder more efficiently; compared to double-layer coating, dynamic dispersion makes the oxygen-rich nanoparticles less prone to agglomeration and results in lower interfacial resistance, demonstrating more significant advantages.

[0212] like Figure 1 As shown, this figure is a scanning electron microscope image of the microporous layer composite powder.

[0213] like Figure 2 As shown in the figure, this is an elemental distribution diagram (aluminum) of the microporous layer composite powder. It can be seen from the figure that the bright-colored oxygen-rich nanoparticles are uniformly distributed on the surface of the microporous layer composite powder, with a high coverage rate.

[0214] like Figure 3 As shown in the figure, this is a flowchart of the preparation method of oxygen-rich nanoparticles in the embodiment.

[0215] like Figure 4 As shown, this figure is a scanning electron microscope image of the microporous layer in the embodiment. Figure 4 It can be seen that the composite microporous layer composite powder can be coated to form a relatively uniform gas diffusion layer.

[0216] Figure 5 This is a schematic diagram of the gas diffusion layer in some embodiments of this application. As can be seen from the figure, the gas diffusion layer is closely attached to the surface of the catalyst layer. After air passes through the microporous layer in the gas diffusion layer, the oxygen concentration can be increased. At the same time, since the oxygen-rich nanoparticles in the microporous layer have hygroscopic and water-retaining functions, they help retain the liquid water generated by the catalyst layer, thereby increasing the humidity of the membrane electrode and thus improving its performance.

[0217] Figure 6This is a comparison chart of the output performance of fuel cells according to some embodiments of this application. The comparison chart shows the same pattern as the above results: the microporous layer composite powder of oxygen-enriched nanoparticles with a particle size between 60 nm and 100 nm, a pore size between 0.2 nm and 0.8 nm, and a mass fraction ratio of oxygen to silicon between 0.6 and 1.2 has good performance in preparing gas diffusion layers. The best performance is achieved when the particle size is 80 nm, the pore size is 0.6 nm, and the oxygen-silicon ratio is 0.8.

[0218] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A microporous layer composite powder for preparing a gas diffusion layer for a fuel cell, characterized in that, The microporous layer composite powder comprises porous carbon and oxygen-rich nanoparticles, wherein the oxygen-rich nanoparticles are at least attached to the surface of the porous carbon, and the oxygen-rich nanoparticles satisfy the following conditions: The oxygen-rich nanoparticles include aluminosilicates or aluminosilicate oxides. The oxygen-rich nanoparticles have a particle size of 60 nm to 100 nm. The oxygen-rich nanoparticles have a porous structure with a pore size of 0.2 nm to 0.8 nm. In the oxygen-rich nanoparticles, the ratio of the mass fraction of oxygen to the mass fraction of silicon ranges from 0.6 to 1.

2.

2. The microporous layer composite powder according to claim 1, characterized in that, The oxygen-rich nanoparticles satisfy the following: The oxygen-rich nanoparticles have a particle size of 60 nm to 80 nm. The oxygen-rich nanoparticles have a porous structure with a pore size of 0.2 nm to 0.6 nm. In the oxygen-rich nanoparticles, the ratio of the mass fraction of oxygen to the mass fraction of silicon ranges from 0.6 to 1.

3. The microporous layer composite powder according to claim 1, characterized in that, The oxygen-rich nanoparticles satisfy the following: The oxygen-rich nanoparticles have a particle size of 60-80 nm. The oxygen-rich nanoparticles have a porous structure with a pore size of 0.4 nm to 0.6 nm. In the oxygen-rich nanoparticles, the mass fraction of oxygen and the mass fraction of silicon are 0.6-0.

8.

4. A method for preparing a microporous layer composite powder, characterized in that, include: A silicon source, an aluminum source, an oxygen source, and a template agent are mixed, pre-crystallized, and crystallized to obtain oxygen-rich nanoparticles. The oxygen-rich nanoparticles have a particle size of 60 nm to 100 nm, a pore size of 0.2 nm to 0.8 nm, and a ratio of the mass fraction of oxygen to the mass fraction of silicon ranging from 0.6 to 1.

2. The oxygen-rich nanoparticles and porous carbon are combined by dynamic permeation to obtain a microporous composite powder, wherein the oxygen-rich nanoparticles are at least attached to the surface of the porous carbon.

5. The method for preparing the microporous layer composite powder according to claim 4, characterized in that, The steps of mixing, pre-crystallizing, and crystallizing silicon, aluminum, and oxygen sources with a template agent include: The silicon source, aluminum source, oxygen source and template agent are mixed and stirred evenly to obtain the first gel; The first gel is then pre-crystallized to obtain the second gel; The second gel was crystallized and then calcined to obtain the oxygen-rich nanoparticles. The molar ratio of the oxygen source to the silicon source ranges from 0.5 to 1.5:

1. And / or, the pre-crystallization temperature is 80°C to 100°C, and the time is 6h to 12h; And / or, the crystallization temperature is 120°C to 180°C, and the time is 24h to 72h; And / or, the crystallization pressure is from 0.5 MPa to 2 MPa; And / or, the concentration of the template agent is from 0.05 mol / L to 0.55 mol / L.

6. The method for preparing the microporous layer composite powder according to claim 4, characterized in that, The silicon source includes at least one of silica sol, sodium silicate solution, silicic acid solution, and methyltriethoxysilane; and / or The aluminum source includes at least one of aluminum isopropoxide, aluminum nitrate, aluminum sulfate, and aluminum chloride; and / or The oxygen source includes hydrogen peroxide; and / or The template agent includes at least one of tetrapropylammonium hydroxide and hexadecyltrimethylammonium bromide.

7. The method for preparing the microporous layer composite powder according to claim 4, characterized in that, The molar ratio of the silicon source to the aluminum source ranges from 30 to 50:1; and / or The molar ratio of the template agent to the silicon source ranges from 0.2 to 0.4:

1.

8. The method for preparing the microporous layer composite powder according to any one of claims 4 to 7, characterized in that, The steps of combining the oxygen-rich nanoparticles and porous carbon via dynamic permeation include: The oxygen-rich nanoparticles were stirred and uniformly infiltrated into the porous carbon to obtain a wet gel. The wet gel is dried by gradually increasing the temperature at a preset temperature; The stirring speed is 500-1500 rpm / min, and the stirring time is 1 to 4 hours; and / or The preset temperature is 60°C to 110°C.

9. A microporous layer slurry, characterized in that, It includes a solvent, additives, and the microporous layer composite powder according to any one of claims 1 to 3; or it includes a solvent, additives, and the microporous layer composite powder prepared by the preparation method according to any one of claims 4 to 8.

10. A gas diffusion layer, characterized in that, It includes a substrate layer and a microporous layer coated on the substrate layer, the microporous layer being formed by coating the substrate layer with the microporous layer slurry as described in claim 9.

11. A fuel cell, characterized in that, The fuel cell includes the gas diffusion layer as described in claim 10.

12. An electrical-related device, characterized in that, The electrical equipment includes the fuel cell as described in claim 11.

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