Microporous layer and preparation method and application thereof

Abstract

The invention relates to a microporous layer and a preparation method and application thereof, and belongs to the technical field of fuel cells. The microporous layer comprises a plurality of hydrophilic areas and a plurality of hydrophobic areas, the plurality of hydrophilic areas are distributed in a spaced latticed manner, the plurality of hydrophobic areas are also distributed in a spaced latticed manner, and the hydrophilic areas and the hydrophobic areas are adjacently arranged; by adopting the latticed hydrophilic and hydrophobic distribution design, water generated in the reaction area of the fuel cell can be uniformly and quickly absorbed, and because the hydrophilic area is also distributed in a latticed manner, the frozen area cannot be concentrated through the division of the mode, so that the gas is uniformly transmitted to the reaction area, and the reaction efficiency of the fuel cell is improved. And the problem that the performance of the fuel cell is influenced by internal water condensation in a low-temperature environment is solved.

Description

Technical Field

[0001] The present application relates to the field of fuel cell technology, and in particular to a microporous layer and a preparation method and application thereof. Background Art

[0002] During the operation of the fuel cell, water is needed to keep the proton exchange membrane moist, thereby ensuring smooth ion transmission and a good state of the ionomer. If there is too much liquid water in the fuel cell, a large amount of liquid water will occupy the gas transmission channel, causing "flooding". Therefore, the liquid water inside the fuel cell needs to be able to keep the proton exchange membrane moist and prevent "flooding", so that the performance of the fuel cell can reach a better state.

[0003] In a sub-zero low-temperature environment, water generated by electrochemical reactions in fuel cells will freeze inside the fuel cell, preventing the cathode reaction gas from reaching the catalyst layer to react, and even causing irreversible performance degradation of the fuel cell, and damaging the structure and performance of the fuel cell components. After liquid water is generated in the cathode catalyst layer, it needs to pass through the microporous layer and the gas diffusion layer to reach the gas flow channel. Therefore, effective water management in the microporous layer and the gas diffusion layer is crucial to improving the low-temperature startup performance of the fuel cell.

[0004] At present, in the prior art, Chinese invention patent application CN105098123A discloses a microporous layer with enhanced ice storage capacity for a fuel cell, wherein the solution defines a plurality of pores in the microporous layer, and the plurality of pores extend between the opposite surfaces of the microporous layer and are arranged to concentrate the formation of ice in the pores under an icing environment to reduce the amount of water frozen in the catalyst layer. The microporous layer also includes a first layer and a second layer, wherein the first layer is adjacent to the catalyst layer and is hydrophilic, and the second layer is between the first layer and the diffusion layer and is hydrophobic, wherein a plurality of pores are defined in the second layer, and the pores are hydrophilic. The purpose is to concentrate the water in the fuel cell in the pores, so that the water freezes in the pores, while the area outside the pores realizes normal water gas transmission. However, it does not take into account the influence of the pore size in the porous medium of the fuel cell on the cold start. Chinese invention patent application CN116190685A discloses a gradient diffusion layer and a preparation method thereof, wherein the solution uses 3D printing technology to print the gas diffusion layer of the fuel cell, and the porosity of the diffusion layer is gradient in the vertical direction. Although this solution can obtain accurate pore distribution, it can only achieve rapid drainage and gas transmission of fuel cells at normal temperatures, but it does not provide much assistance for cold start. Chinese invention patent application CN113921832A discloses a microporous layer material for water / gas separation and transmission, and its preparation method and application. This solution provides a new idea for separation and transmission of reaction gas and liquid product water. It uses hollow porous nanocarbon fibers (H-PCNF) with hydrophilic / hydrophobic specificity on the inner / outer surfaces and through holes on the surface to the hollow part as microporous layer materials, which can achieve the purpose of separation and transmission of reaction gas and liquid product water in membrane electrodes. However, it also does not take into account the effect of pore size in the porous medium of fuel cells on cold start. Summary of the invention

[0005] The present application provides a microporous layer and a preparation method and application thereof, so as to improve the problem that the performance of a fuel cell is affected by internal water condensation in a low temperature environment.

[0006] In a first aspect, the present application provides a microporous layer, which includes multiple hydrophilic regions and multiple hydrophobic regions, wherein the multiple hydrophilic regions are distributed in a spaced grid-like manner, the multiple hydrophobic regions are also distributed in a spaced grid-like manner, and the hydrophilic regions and the hydrophobic regions are adjacently arranged.

[0007] As an optional implementation, the micropore diameter of the hydrophilic region is larger than the micropore diameter of the hydrophobic region.

[0008] As an optional embodiment, the micropore diameter of the hydrophilic region is 150nm to 200nm; and / or

[0009] The pore size of the hydrophobic region is 50 nm to 100 nm.

[0010] As an optional implementation manner, the ratio of the area of ​​the hydrophilic region to the area of ​​the hydrophobic region is (0.5-1.5):(0.5-1.5).

[0011] As an optional implementation, the components of the hydrophilic region include polyamide resin and acetylene black.

[0012] As an optional implementation, the components of the hydrophobic region include polytetrafluoroethylene and acetylene black.

[0013] In a second aspect, the present application provides a method for preparing a microporous layer, wherein the microporous layer is the microporous layer provided in the first aspect; the method comprises:

[0014] Obtaining a hydrophilic slurry and a hydrophobic slurry;

[0015] The hydrophilic slurry and the hydrophobic slurry are applied to a base layer and sintered to obtain a microporous layer.

[0016] As an optional embodiment, the sintering temperature is 250° C. to 450° C.; and / or

[0017] The sintering time is 20 min to 40 min.

[0018] As an optional implementation, the substrate layer includes a gas diffusion layer.

[0019] In a third aspect, the present application provides a fuel cell, comprising the microporous layer provided in the first aspect.

[0020] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0021] The microporous layer provided in the embodiment of the present application adopts a grid-like hydrophilic and hydrophobic distribution design to uniformly and quickly absorb the water generated in the reaction area of ​​the fuel cell. Moreover, since the hydrophilic area is also distributed in a grid shape, the ice area will not be concentrated through this division, thereby ensuring that the gas is evenly transmitted to the reaction area, thereby improving the problem of fuel cell performance being affected by internal water condensation in a low temperature environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0023] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0024] Figure 1 A schematic diagram of the structure of the microporous layer provided in an embodiment of the present application;

[0025] Figure 2 A flowchart of the method provided in the embodiment of the present application. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0027] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0028] In a sub-zero low-temperature environment, water generated by the electrochemical reaction in a proton exchange membrane fuel cell will freeze inside the fuel cell, preventing the reaction gas at the cathode from reaching the catalyst layer to react, and may even cause irreversible performance degradation of the fuel cell and damage the structure and performance of the fuel cell components.

[0029] Currently, most strategies for improving the low-temperature starting performance of fuel cells require complex auxiliary equipment and consume additional energy. However, the most direct way to improve the self-starting ability of the battery is to effectively improve the water management ability inside the battery, while discharging liquid water in a timely manner and ensuring that the reaction gas reaches the catalyst layer interface. Among them, the water management ability on the cathode side of the membrane electrode is the most important.

[0030] In response to the water vapor transmission and freezing problems of fuel cells in low-temperature starting conditions, the present application improves the low-temperature starting performance of the battery and reduces the impact on the fuel cell stack by optimizing the cathode side membrane electrode structure and water management capabilities. Specifically, the present application adopts a microporous layer with a grid-like hydrophilic and hydrophobic distribution, and combines it with the pore size to improve the cold start capability of the fuel cell. The grid-like hydrophilic and hydrophobic distribution design can evenly and quickly absorb the water generated in the reaction area of ​​the fuel cell, and because the hydrophilic area is also distributed in a grid shape, the ice area will not be more concentrated through this division, thereby ensuring that the gas is evenly transmitted to the reaction area. And the present invention combines hydrophobicity with pore size, the hydrophilic area has a larger pore size, and the hydrophobic area has a smaller pore size. The large-pore hydrophilic area can quickly absorb the water generated by the catalyst layer, and the smaller pore size of the hydrophobic area can form a pressure gradient with the diffusion layer, so that the gas is quickly transmitted.

[0031] Figure 1 The schematic diagram of the structure of the microporous layer provided in the embodiment of the present application is as follows: Figure 1 As shown, an embodiment of the present application provides a microporous layer, which includes multiple hydrophilic regions and multiple hydrophobic regions, the multiple hydrophilic regions are distributed in a grid-like manner at intervals, the multiple hydrophobic regions are also distributed in a grid-like manner at intervals, and the hydrophilic regions and the hydrophobic regions are arranged adjacent to each other.

[0032] The plurality of hydrophilic regions are distributed in a grid-like manner at intervals, and the plurality of hydrophobic regions are also distributed in a grid-like manner at intervals, and the adjacent arrangement of the hydrophilic regions and the hydrophobic regions means that each hydrophilic region is surrounded by adjacent hydrophobic regions, and similarly, each hydrophobic region is surrounded by adjacent hydrophilic regions. The distribution of the entire hydrophilic region and the hydrophobic region is similar to the distribution of black squares and white squares on a chessboard.

[0033] The microporous layer adopts a grid-like hydrophilic and hydrophobic distribution design to evenly and quickly absorb the water generated in the fuel cell reaction area. Since the hydrophilic area is also distributed in a grid pattern, this division can prevent the ice area from being concentrated, thereby ensuring that the gas is evenly transmitted to the reaction area, thereby improving the problem of fuel cell performance being affected by internal water condensation in a low temperature environment.

[0034] In some embodiments, the micropores of the hydrophilic region have a larger pore size than the micropores of the hydrophobic region. The micropores of the hydrophilic region have a larger pore size, which can quickly absorb water generated by the catalyst layer, and once the water in the hydrophilic region freezes and blocks, the hydrophobic region can leave a channel for gas diffusion, and the gas can be transmitted from the hydrophobic region. The pore size of the hydrophobic region is smaller, which can form a pressure gradient with the gas diffusion layer, allowing the gas to be quickly transmitted, thereby improving the cold start performance of the fuel cell.

[0035] Furthermore, the micropore diameter of the hydrophilic region is 150-200 nm, the pore diameter of the hydrophobic region is 50-100 nm, and the area ratio of the hydrophilic region to the hydrophobic region is (0.5-1.5):(0.5-1.5).

[0036] Figure 2 A flow chart of the method provided in the embodiment of the present application is as follows: Figure 2 As shown, based on a general inventive concept, an embodiment of the present application further provides a method for preparing a microporous layer, wherein the microporous layer is the microporous layer provided above; the method comprises:

[0037] S1. Obtaining a hydrophilic slurry and a hydrophobic slurry;

[0038] Specifically, in the present embodiment, the preparation process of the hydrophilic slurry can be: after polyamide resin, acetylene black, isopropanol and deionized water are poured into a beaker in a certain ratio, a mechanical stirrer is used to stir 20min at 1000rpm, and the hydrophilic slurry is completed. The preparation process of the hydrophobic slurry can be: after PTFE concentrated dispersion, acetylene black, isopropanol and deionized water are poured into a beaker in a certain ratio, a mechanical stirrer is used to stir 20min at 1000rpm, and the hydrophobic slurry is completed. Wherein, isopropanol and deionized water are used to fully mix acetylene black and PTFE, acetylene black and polyamide resin.

[0039] S2. Applying the hydrophilic slurry and the hydrophobic slurry to the base layer, and sintering the slurry to obtain a microporous layer.

[0040] In some embodiments, the sintering temperature is 250°C to 450°C; the sintering time is 20 min to 40 min. Exemplarily, the sintering temperature can be 250°C, 260°C, 270°C, 280°C, 290°C, 300°C, 310°C, 320°C, 330°C, 340°C, 350°C, 360°C, 370°C, 380°C, 390°C, 400°C, 410°C, 420°C, 430°C, 440°C or 450°C, etc., and it can also be any value within the range of 250°C to 450°C. The sintering time can be 20min, 21min, 22min, 23min, 24min, 25min, 26min, 27min, 28min, 29min, 30min, 31min, 32min, 33min, 34min, 35min, 36min, 37min, 38min, 39min or 40min, etc., and it can also be any value within the range of 20min to 40min.

[0041] Specifically, in this embodiment, the base layer is fixed, and the mold and the base layer are fixed. After the fixing is completed, the hydrophilic slurry is evenly poured on the base layer. After the slurry is evenly coated on the base layer, it is placed in a vacuum drying oven and sintered at a high temperature of 300°C for 30 minutes. After the temperature of the vacuum drying oven drops to room temperature, the sample is taken out, and the hydrophilic area is completed. Then the base layer with a grid-shaped hydrophilic area is fixed, and the mold is fixed to it. After the fixing is completed, the hydrophobic slurry is evenly poured on the base layer. After the slurry is evenly coated on the base layer, it is placed in a vacuum drying oven and sintered at a high temperature of 400°C for 30 minutes. After the temperature of the vacuum drying oven drops to room temperature, the sample is taken out, and the microporous layer is completed. It is understandable that in other embodiments, the hydrophobic area can be prepared first, and then the hydrophilic area can be prepared. Specifically, the base layer is fixed, and the mold and the base layer are fixed. After the fixing is completed, the hydrophobic slurry is evenly poured on the base layer. After the slurry is evenly coated on the base layer, it is placed in a vacuum drying oven and sintered at a high temperature of 400°C for 30 minutes. After the temperature of the vacuum drying oven drops to room temperature, the sample is taken out, and the hydrophobic area is completed. Then fix the base layer in which the grid-shaped hydrophobic area has been prepared, and fix the mold with it. After the fixing is completed, the hydrophilic slurry is evenly poured on the base layer. After the slurry is evenly coated on the base layer, it is placed in a vacuum drying oven and sintered at a high temperature of 300°C for 30 minutes. After the temperature of the vacuum drying oven drops to room temperature, the sample is taken out, and the microporous layer is completed.

[0042] This method is used to prepare the above-mentioned microporous layer. The specific content of the microporous layer can refer to the above-mentioned embodiment. Since this method adopts part or all of the technical solutions of the above-mentioned embodiment, it at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiment, which will not be repeated here one by one.

[0043] The present application will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are intended only to illustrate the present application and are not intended to limit the scope of the present application. The experimental methods for which specific conditions are not specified in the following examples are usually measured according to national standards. If there is no corresponding national standard, then the conditions recommended by the manufacturer are followed.

[0044] Example 1

[0045] A microporous layer, the preparation process of which is as follows:

[0046] After pouring polyamide resin, acetylene black, isopropyl alcohol and deionized water into a beaker in a certain proportion, wherein the mass proportion of polyamide resin is 20%, a mechanical stirrer is used to stir at 1000 rpm for 20 minutes, and the hydrophilic slurry is completed.

[0047] After pouring PTFE concentrated dispersion, acetylene black, isopropyl alcohol and deionized water into a beaker in a certain proportion, wherein PTFE accounts for 20% by mass, a mechanical stirrer is used to stir at 1000 rpm for 20 minutes, and the hydrophobic slurry is prepared.

[0048] Fix the base layer, and fix the mold and the base layer. After fixing, pour the hydrophilic slurry evenly on the base layer. After the slurry is evenly coated on the base layer, put it in a vacuum drying oven and sinter it at a high temperature of 300°C for 30 minutes. After the temperature of the vacuum drying oven drops to room temperature, take out the sample, and the hydrophilic area is completed. Then fix the base layer with the hydrophilic area distributed in a grid, and fix the mold to it. After fixing, pour the hydrophobic slurry evenly on the base layer. After the slurry is evenly coated on the base layer, put it in a vacuum drying oven and sinter it at a high temperature of 400°C for 30 minutes. After the temperature of the vacuum drying oven drops to room temperature, take out the sample, and the microporous layer is completed.

[0049] The micropore diameter of the hydrophilic region of the microporous layer is 172 nm, and the micropore diameter of the hydrophobic region is 83 nm.

[0050] Example 2

[0051] A microporous layer, the preparation process of which is as follows:

[0052] After pouring polyamide resin, acetylene black, isopropyl alcohol and deionized water into a beaker in a certain proportion, wherein the mass proportion of polyamide resin is 10%, a mechanical stirrer is used to stir at 1000 rpm for 20 minutes, and the hydrophilic slurry is completed.

[0053] After pouring PTFE concentrated dispersion, acetylene black, isopropyl alcohol and deionized water into a beaker in a certain proportion, wherein PTFE accounts for 10% by mass, a mechanical stirrer is used to stir at 1000 rpm for 20 minutes, and the hydrophobic slurry is ready.

[0054] Fix the base layer, and fix the mold and the base layer. After fixing, pour the hydrophilic slurry evenly on the base layer. After the slurry is evenly coated on the base layer, put it in a vacuum drying oven and sinter it at a high temperature of 300°C for 30 minutes. After the temperature of the vacuum drying oven drops to room temperature, take out the sample, and the hydrophilic area is completed. Then fix the base layer with the hydrophilic area distributed in a grid, and fix the mold to it. After fixing, pour the hydrophobic slurry evenly on the base layer. After the slurry is evenly coated on the base layer, put it in a vacuum drying oven and sinter it at a high temperature of 400°C for 30 minutes. After the temperature of the vacuum drying oven drops to room temperature, take out the sample, and the microporous layer is completed.

[0055] The micropore diameter of the hydrophilic region of the microporous layer is 155 nm, and the micropore diameter of the hydrophobic region is 52 nm.

[0056] Example 3

[0057] A microporous layer, the preparation process of which is as follows:

[0058] After pouring polyamide resin, acetylene black, isopropyl alcohol and deionized water into a beaker in a certain proportion, wherein the mass proportion of polyamide resin is 30%, a mechanical stirrer is used to stir at 1000 rpm for 20 minutes, and the hydrophilic slurry is prepared.

[0059] After pouring PTFE concentrated dispersion, acetylene black, isopropyl alcohol and deionized water into a beaker in a certain proportion, wherein PTFE accounts for 30% by mass, a mechanical stirrer is used to stir at 1000 rpm for 20 minutes, and the hydrophobic slurry is ready.

[0060] Fix the base layer, and fix the mold and the base layer. After fixing, pour the hydrophilic slurry evenly on the base layer. After the slurry is evenly coated on the base layer, put it in a vacuum drying oven and sinter it at a high temperature of 300°C for 30 minutes. After the temperature of the vacuum drying oven drops to room temperature, take out the sample, and the hydrophilic area is completed. Then fix the base layer with the hydrophilic area distributed in a grid, and fix the mold to it. After fixing, pour the hydrophobic slurry evenly on the base layer. After the slurry is evenly coated on the base layer, put it in a vacuum drying oven and sinter it at a high temperature of 400°C for 30 minutes. After the temperature of the vacuum drying oven drops to room temperature, take out the sample, and the microporous layer is completed.

[0061] The micropore diameter of the hydrophilic region of the microporous layer is 169 nm, and the micropore diameter of the hydrophobic region is 97 nm.

[0062] Comparative Example 1

[0063] A microporous layer, the preparation process of which is as follows:

[0064] After pouring PTFE concentrated dispersion, acetylene black, isopropyl alcohol and deionized water into a beaker at a ratio of 10% by mass of PTFE, a mechanical stirrer was used to stir at 1000 rpm for 20 minutes, and the hydrophobic slurry was prepared.

[0065] Fix the base layer, and fix the mold and the base layer. After fixing, pour the hydrophilic slurry evenly on the base layer. After the slurry is evenly coated on the base layer, put it into a vacuum drying oven and sinter it at a high temperature of 400°C for 30 minutes. After the temperature of the vacuum drying oven drops to room temperature, take out the sample and the hydrophobic microporous layer is completed.

[0066] The micropore diameter of the microporous layer is 83 nm.

[0067] Comparative Example 2

[0068] A microporous layer, the preparation process of which is as follows:

[0069] After the polyamide resin, acetylene black, isopropyl alcohol and deionized water are poured into a beaker with a polyamide resin weight ratio of 20%, a mechanical stirrer is used to stir at 1000 rpm for 20 minutes, and the hydrophilic slurry is prepared.

[0070] Fix the base layer, and fix the mold and the base layer. After fixing, pour the hydrophilic slurry evenly on the base layer. After the slurry is evenly coated on the base layer, put it into a vacuum drying oven and sinter it at a high temperature of 300°C for 30 minutes. After the temperature of the vacuum drying oven drops to room temperature, take out the sample and the hydrophilic microporous layer is completed.

[0071] The micropore diameter of the microporous layer is 172 nm.

[0072] The microporous layers provided in each embodiment and comparative example were assembled into a fuel cell, and its performance was tested. The results are shown in the following table:

[0073]

[0074]

[0075] It can be seen from the above table that the microporous layer provided by the embodiment of the present application has good cold start performance.

[0076] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present application; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, the range description from 1 to 6 should be considered to have specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0077] In the present application, in the absence of any contrary description, the directional words used, such as "upper" and "lower", are specifically the directions of the drawings in the accompanying drawings. In addition, in the description of the present specification, the terms "including", "comprising", etc. refer to "including but not limited to". In this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. In this article, "and / or" describes the association relationship of the associated objects, indicating that there may be three relationships, for example, A and / or B, which can represent: A exists alone, A and B exist at the same time, and B exists alone. Wherein A, B can be singular or plural. In this article, "at least one" refers to one or more, and "plural" refers to two or more. "At least one", "at least one of the following" or similar expressions refer to any combination of these items, including any combination of singular or plural items. For example, "at least one of a, b, or c", or "at least one of a, b and c", can both mean: a, b, c, ab (i.e. a and b), ac, bc or abc, where a, b, c can be single or plural, respectively.

[0078] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A microporous layer, characterized in that: The microporous layer includes a plurality of hydrophilic regions and a plurality of hydrophobic regions, wherein the plurality of hydrophilic regions are distributed in a grid-like manner at intervals, and the plurality of hydrophobic regions are also distributed in a grid-like manner at intervals, and the hydrophilic regions and the hydrophobic regions are adjacently arranged.

2. The microporous layer according to claim 1, characterized in that The micropore diameter of the hydrophilic region is larger than the micropore diameter of the hydrophobic region.

3. The microporous layer according to claim 1 or 2, characterized in that The micropore diameter of the hydrophilic region is 150nm to 200nm; and / or The pore size of the hydrophobic region is 50 nm to 100 nm.

4. The microporous layer according to claim 1, characterized in that The ratio of the area of ​​the hydrophilic region to the area of ​​the hydrophobic region is (0.5-1.5):(0.5-1.5).

5. The microporous layer according to claim 1, characterized in that The components of the hydrophilic region include polyamide resin and acetylene black.

6. The microporous layer according to claim 1, characterized in that The composition of the hydrophobic region includes polytetrafluoroethylene and acetylene black.

7. A method for preparing a microporous layer, characterized in that: The microporous layer is the microporous layer according to any one of claims 1 to 6; the method comprises: Obtaining a hydrophilic slurry and a hydrophobic slurry; The hydrophilic slurry and the hydrophobic slurry are applied to a base layer and sintered to obtain a microporous layer.

8. The method for preparing a microporous layer according to claim 7, characterized in that: The sintering temperature is 250°C to 450°C; and / or The sintering time is 20 min to 40 min.

9. The method for preparing a microporous layer according to claim 7, characterized in that: The substrate layer includes a gas diffusion layer.

10. A fuel cell, characterized in that: The fuel cell comprises the microporous layer according to any one of claims 1 to 6.

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