A method for preparing a microporous layer having an ordered pore structure

Abstract

The application discloses a preparation method of a microporous layer with ordered pore structure, and mainly comprises the following steps: preparing a groove-ridge mask plate through a wire cutting method; preparing a carbon paper cutter die through a stamping method; mixing carbon black, a pore-forming agent polymethyl methacrylate and polytetrafluoroethylene to prepare slurry I; mixing the carbon black and the polytetrafluoroethylene to prepare slurry II; spraying the two kinds of slurries on the hydrophobic carbon paper of the cutter die slice in sequence according to the order of the groove mask plate and the ridge mask plate; and finally, baking the sprayed microporous layer in a muffle furnace to obtain the microporous layer with ordered pore structure. The groove mask plate and the ridge mask plate are both provided with a rectangular window, and the window is used for spraying the slurry. The used mask plate can be designed into various arrangement modes according to the distribution of the flow field groove and the ridge, different slurries are sprayed by using the mask plate, the pore-forming agent establishes ordered pores on the gas-liquid transmission channel of the microporous layer, the gas-liquid transmission rate is improved, the heat and mass transfer function of the microporous layer is effectively improved, and the demand of the battery for rapid ventilation and drainage under high current density can be met.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of fuel cells, and particularly relates to a microporous layer preparation plate with an ordered pore structure and a preparation method. BACKGROUND

[0002] Proton exchange membrane fuel cell (PEMFC) is an important carrier for realizing the "double carbon" goal as a green and efficient energy conversion device. The microporous layer is a key component in the fuel cell, which can improve the pore size distribution of the diffusion layer, reduce the contact resistance between the catalyst layer and the diffusion layer, and promote gas and liquid transport and heat transfer. Currently, conductive carbon black and hydrophobic agent polytetrafluoroethylene are commonly used in the preparation of microporous layers. Carbon black ensures conductivity, and polytetrafluoroethylene ensures drainage, thereby ensuring efficient operation of the battery.

[0003] The material type, preparation method and hydrophilic / hydrophobic property of the microporous layer will affect the performance of the PEMFC. After high-temperature treatment, larger crack structures will be formed inside the microporous layer, which can ensure that the reaction gas can be transmitted from the small pores between the particles to the catalyst layer, and the liquid water generated by the reaction can be discharged from the larger cracks. However, the existing disordered pore structure of the microporous layer cannot meet the requirements of gas and water transmission at high current density. Therefore, the focus of current research and development is to reasonably design the pore structure of the microporous layer and construct efficient gas and liquid transport channels.

[0004] Patent with publication number CN113241448B discloses a proton exchange membrane fuel cell gradient microporous gas diffusion layer and a preparation method thereof. Conductive carbon black, multi-walled carbon nanotubes and graphite sheets are respectively prepared into slurry I, slurry II and slurry III, and then coated on the surface of a hydrophobic carbon paper in different orders, dried and heat treated to obtain a microporous layer with a pore gradient and a hydrophobic gradient. The gradient design in the thickness direction of this microporous layer can improve water management, but the composition of the slurry is complex and the flow field distribution in the horizontal direction is not considered.

[0005] Patent with publication number CN115719818A discloses a fuel cell gas diffusion layer with an ordered structure and a preparation method thereof. The main structure and the network structure of the diffusion layer are prepared by using 3D printing technology, then carbonization treatment is performed, then the diffusion layer after carbonization is treated with a hydrophobic agent, and finally the microporous layer slurry is coated on the network structure of the gas diffusion layer by silk screen printing. This invention designs the pattern in the horizontal direction of the diffusion layer by 3D printing, but the design in the horizontal direction of the microporous layer is not considered.

[0006] There is no related report on designing the pore structure of the microporous layer referring to the flow field groove and ridge, and realizing ordering in the current technology. The present application provides a microporous layer preparation method with a pore structure having a flow field groove feature. SUMMARY

[0007] To solve the defects of the micro-porous layer in the horizontal direction of the structure design preparation, the purpose of the present application is to provide a preparation method of a micro-porous layer with an ordered pore structure.

[0008] The present application is realized by the following technical solutions:

[0009] A preparation method of a micro-porous layer with an ordered pore structure comprises the following steps:

[0010] (1) A groove mask plate according to the windowing of the flow field groove structure and a ridge mask plate according to the windowing of the flow field ridge structure are prepared by a wire cutting method; a carbon paper cutter is prepared by a stamping method, the carbon paper cutter comprises a substrate, a square blade and 8 positioning hole blades, windows for spraying slurry are opened on the groove mask plate and the ridge mask plate, and the groove mask plate and the ridge mask plate are both provided with positioning holes at the same position and correspond to the positioning hole blades of the carbon paper cutter.

[0011] (2) The conductive carbon black, polytetrafluoroethylene and pore-forming agent polymethyl methacrylate are placed in anhydrous ethanol solution to prepare slurry I containing a pore-forming agent.

[0012] (3) The conductive carbon black and polytetrafluoroethylene are placed in anhydrous ethanol solution to prepare slurry II without a pore-forming agent.

[0013] (4) The positioning holes of the carbon paper cutter are used to cut positioning holes on the hydrophobic treated carbon paper. The groove mask plate is covered on the hydrophobic carbon paper by using the positioning holes, slurry I is sprayed on the carbon paper through the windows of the groove mask plate by an ultrasonic spraying method, and then the groove mask plate is removed. The ridge mask plate is still covered on the carbon paper sprayed with slurry I by using the positioning holes, slurry II is sprayed through the windows of the ridge mask plate to form a carbon paper substrate with two kinds of micro-porous layers.

[0014] (5) The carbon paper sprayed with the two kinds of slurry is placed in a muffle furnace for calcination, so that the polytetrafluoroethylene is melted and the pore-forming agent polymethyl methacrylate is decomposed, and a micro-porous layer with an ordered pore distribution under the structure characteristics of “groove” and “ridge” is obtained.

[0015] The micro-porous layer is a key component in a fuel cell, and gaseous reactants and liquid products flow through the micro-porous layer. The ordered micro-porous layer with the structure characteristics of grooves and ridges constructs large pore channels under the flow field grooves to improve gas-liquid transmission and realize large pore water and small pore gas; and constructs conventional pores under the flow field ridges to ensure electron conduction.

[0016] In the present application, the mask plate is used to make the microporous layer with ordered pore structure on the carbon paper. The final step is to bake the microporous layer slurry sprayed on the surface of the carbon paper, and the mask plate is used to divide the two kinds of slurry in the spraying process. The ordered pore structure is designed according to the flow channel ridge, which aims to produce large pores in the microporous layer directly above the flow channel, and to improve the gas-liquid transmission.

[0017] Compared with the prior art, the present application has the following characteristics:

[0018] (1) The mask plate with two structural characteristics can match the microporous layer pore structure with the flow channel, effectively improve the gas-liquid transmission capacity of the fuel cell, and further improve the power density of the cell.

[0019] (2) By using the mask plate to spray different slurries, the pore former can establish ordered pores on the gas-liquid transmission channel of the microporous layer, improve the gas-liquid transmission rate, effectively improve the heat and mass transfer function of the microporous layer, and meet the demand of the cell for rapid ventilation and drainage under high current density.

[0020] (3) The preparation and processing steps of the present application are simple, the raw materials and methods are economical and suitable, and only the mask plate and the pore former are added in the microporous layer preparation process, which is simple to operate and can be used for mass production.

[0021] (4) The establishment of the ordered pore structure of the microporous layer effectively improves the water management capacity, and the water generated in the cathode can enter the flow field along the established ordered pore structure, which can effectively improve the waterlogging phenomenon of the fuel cell. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a schematic diagram of the mask plate spraying process of the present application.

[0023] Figure 2 is a structural diagram of the mask plate in the present application.

[0024] Figure 3 is a flow chart of the preparation of the ordered microporous layer of the present application.

[0025] Figure 4 is an electron microscope picture of the microporous layer surface on the carbon paper after the pore former slurry is sprayed and baked.

[0026] Figure 5 is an electron microscope picture of the microporous layer surface on the carbon paper after the part of the pore former slurry II is sprayed and baked. DETAILED DESCRIPTION

[0027] The following refers to the accompanying Figures 1-5 The method of the present application is described in detail by examples. It should be noted that the examples are presented to clearly explain the steps of the present application, and do not constitute a limitation on the technical features of the claims.

[0028] Unless otherwise specifically indicated, all raw materials, reagents, instruments and equipment used in the present application can be purchased on the market or prepared by existing methods.

[0029] The preparation and processing method of the ordered pore structure microporous layer can be carried out by Figure 3 The preparation process is described in detail as follows:

[0030] (1) The groove mask plate according to the windowing of the flow field groove structure and the ridge mask plate according to the windowing of the flow field ridge structure are prepared by a wire cutting method; the carbon paper cutter die is prepared by a stamping method, and the carbon paper cutter die comprises a substrate, a square blade and eight positioning hole blades. The groove mask plate and the ridge mask plate are both provided with a window for spraying slurry, and the window is opposite to the "groove" or "ridge" below. At the same time, the groove mask plate and the ridge mask plate are both provided with positioning holes in the same position and corresponding to the positioning hole blades of the carbon paper cutter die. Figure 2 The structure diagrams of the groove mask plate and the ridge mask plate are given, and the two kinds of mask plates are the same, and the difference lies in that the positions of the spraying windows are different.

[0031] (2) The conductive carbon black, polytetrafluoroethylene and pore-forming agent polymethyl methacrylate (PMMA) are placed in anhydrous ethanol solution to prepare slurry I containing a pore-forming agent.

[0032] (3) The conductive carbon black and polytetrafluoroethylene are placed in anhydrous ethanol solution to prepare slurry II without a pore-forming agent.

[0033] (4) The positioning holes of the carbon paper cutter die are used to cut positioning holes on the hydrophobic treated carbon paper, the groove mask plate is covered on the hydrophobic carbon paper by using the positioning holes, slurry I is sprayed on the carbon paper through the window of the groove mask plate by an ultrasonic spraying method, and then the groove mask plate is removed; the ridge mask plate is still covered on the carbon paper sprayed with slurry I by using the positioning holes, slurry II is sprayed through the window of the ridge mask plate, and a carbon paper substrate with two kinds of microporous layers is formed.

[0034] When slurry II is sprayed, the ridge mask plate covers the position coated with slurry I, and the two kinds of slurries are separated by the partition on the mask plate. The width of the partition is set as the distance of the "groove" and "ridge" in the flow field.

[0035] (5) The carbon paper sprayed with the two kinds of slurries is placed in a muffle furnace for calcination, so that the polytetrafluoroethylene is melted and the pore-forming agent polymethyl methacrylate is decomposed, and a microporous layer with ordered pore distribution under the two structural characteristics of groove and ridge is obtained.

[0036] In step (1), the groove mask plate surface is provided with M rectangular windows, M+1 edges and 8 positioning holes around; the ridge mask plate is provided with N rectangular windows, N+1 edges and 8 positioning holes corresponding to the groove mask plate; the rectangular windows on the groove mask plate correspond to the edges of the ridge mask plate one by one; the rectangular windows on the ridge mask plate correspond to the edges on the groove mask plate one by one, wherein the M rectangular windows correspond to the number of grooves in the flow field; the N rectangular windows correspond to the number of ridges in the flow field.

[0037] In step (2), the mass fraction of conductive carbon black in slurry I is 40-80wt%, the mass fraction of polytetrafluoroethylene is 10-30wt%, and the mass fraction of polymethyl methacrylate is 10-30wt%, and the total solute mass fraction of slurry I is 1.0-2.0wt%; after the slurry is prepared, it is placed in a water bath for 2-4 minutes at 95℃ for aging, so that the polytetrafluoroethylene is more easily dispersed, and then the slurry I is placed in an ultrasonic cleaning machine for ultrasonic vibration for 1-2 hours.

[0038] In step (3), the mass fraction of conductive carbon black in slurry II is 70-90wt%, the mass fraction of polytetrafluoroethylene is 10-30wt%, and the total solute mass fraction of the slurry is 1.0-2.0wt%; after the slurry is prepared, it is placed in a water bath for 2-4 minutes at 95℃ for aging, so that the polytetrafluoroethylene is more easily dispersed, and then the slurry II is placed in an ultrasonic cleaning machine for ultrasonic vibration for 1-2 hours.

[0039] In step (4), the slurry I and the slurry II have the same ultrasonic spraying procedure, after the groove mask plate is sprayed with the slurry I, the ridge mask plate is replaced, so that the area sprayed with the slurry I is shielded by the ridge mask plate, and then the slurry II is sprayed, and the groove and ridge mask plates are positioned with each other through the positioning holes and the positioning holes on the hydrophobic carbon paper to determine the position.

[0040] In step (5), the carbon paper sprayed with the two kinds of microporous layer slurry is baked in a muffle furnace at a temperature of 400℃ for 2-3 hours.

[0041] Figure 1 Figure 1 is a schematic diagram of the mask plate spraying process principle; Figure 2 Figure 2 is a structural diagram of the two mask plates, wherein 1-1 represents the window for spraying slurry on the mask plate; 1-2 represents the partition between the two spraying windows; and 1-3 represents the positioning hole.

[0042] Example 1:

[0043] The preparation of the ordered pore structure microporous layer includes the following steps:

[0044] (1) Wire cutting is used to prepare the groove mask plate and the ridge mask plate suitable for a 5cm×5cm serpentine flow field, and stamping is used to prepare the knife mold suitable for a 5cm×5cm carbon paper.

[0045] The groove mask plate is cut by wire cutting on a 10 cm x 10 cm flat plate to form 25 square window spraying areas and 8 positioning holes, each square window is 50 mm long, 1 mm wide, and the spacing is 2 mm; the ridge mask plate is cut by wire cutting on a 10 cm x 10 cm flat plate to form 25 square window spraying areas and 8 positioning holes, each square window is 50 mm long, 1 mm wide, and the spacing is 2 mm, compared with the groove mask plate, each window is moved down by 1 mm. The carbon paper cutter mold square blade size is 10 cm x 10 cm, and the 8 positioning holes are consistent with the groove and ridge mask plate.

[0046] (2) 0.25 g of XC-72 carbon powder, 0.18 g of 60 wt% polytetrafluoroethylene dispersion, 0.153 g of PMMA and 40 g of anhydrous ethanol were weighed by a balance to prepare slurry I.

[0047] (3) 0.25 g of XC-72 carbon powder, 0.18 g of 60 wt% polytetrafluoroethylene dispersion and 30 g of anhydrous ethanol were weighed by a balance to prepare slurry II.

[0048] (4) The slurry I and the slurry II were heated in a 95℃ water bath for 2 min. Then the slurry I and the slurry II were ultrasonically dispersed for 1 h.

[0049] (5) The hydrophobic treated carbon paper was cut by a cutter mold, and the positioning holes were aligned and placed under the 5 cm x 5 cm serpentine flow field groove mask plate, and the slurry I was sprayed; after the spraying was completed, the 5 cm x 5 cm serpentine flow field ridge mask plate was replaced and the positioning holes were aligned, and the microporous layer with pore forming agent was shielded, and the slurry II was sprayed.

[0050] (6) The carbon paper with attached microporous layer after spraying was placed in a muffle furnace at 400℃ for 3 h, and finally the microporous layer with ordered pore structure was obtained, which was suitable for a 25 cm 2 serpentine flow field.

[0051] This example is based on a 25 cm 2 serpentine flow field, and 25 large-pore microporous layers and 25 conventional-pore microporous layers are prepared on the surface of a 5 cm x 5 cm square carbon paper. Figure 4 is the electron microscope picture of part of the slurry I with pore forming agent after partial calcination in this example, Figure 5 is the electron microscope picture of part of the slurry II without pore forming agent after partial calcination in this example.

[0052] Example 2:

[0053] The preparation of the microporous layer with ordered pore structure includes the following steps:

[0054] (1) The groove mask plate and the ridge mask plate suitable for a 2 cm x 2 cm parallel flow field are prepared by wire cutting, and the cutter mold suitable for a 2 cm x 2 cm carbon paper is prepared by punching.

[0055] The trench mask plate was cut by wire cutting to form 10 square window spraying areas and 8 positioning holes on a 5 cm x 5 cm flat plate, each square window was 20 mm long and 1 mm wide, and the spacing was 2 mm; the ridge mask plate was cut by wire cutting to form 10 square window spraying areas and 8 positioning holes on a 5 cm x 5 cm flat plate, each square window was 20 mm long and 1 mm wide, and the spacing was 2 mm, and each window was moved down by 1 mm compared with the trench mask plate. The carbon paper cutter mold square blade size was 5 cm x 5 cm, and the 8 positioning holes were located in the same position as the trench ridge mask plate.

[0056] (2) 0.1 g of XC-72 carbon powder, 0.072 g of 60 wt% polytetrafluoroethylene dispersion, 0.036 g of PMMA and 15 g of anhydrous ethanol were weighed by a balance to prepare slurry I.

[0057] (3) 0.1 g of XC-72 carbon powder, 0.072 g of 60 wt% polytetrafluoroethylene dispersion and 12 g of anhydrous ethanol were weighed by a balance to prepare slurry II.

[0058] (4) The slurry I and the slurry II were heated in a 95°C water bath for 3 min. Then the slurry I and the slurry II were ultrasonically dispersed for 1.5 h.

[0059] (5) The hydrophobic treated carbon paper was cut by a cutter mold, and the positioning holes were aligned and placed under the 2 cm x 2 cm parallel flow field trench mask plate, and the slurry I was sprayed; after the spraying was completed, the 2 cm x 2 cm parallel flow field ridge mask plate was replaced and the positioning holes were aligned, and the microporous layer with pore forming agent was shielded, and the slurry II was sprayed.

[0060] (6) The carbon paper with attached microporous layer after spraying was placed in a muffle furnace at 400°C for 3 h, and the microporous layer with ordered pore structure was finally obtained, which was suitable for a 4 cm 2 parallel flow field.

[0061] This example prepared 10 large-pore microporous layers and 10 regular-pore microporous layers on the surface of a 2 cm x 2 cm square carbon paper according to a 4 cm 2 parallel flow field.

[0062] Example 3:

[0063] The preparation of the microporous layer with ordered pore structure includes the following steps:

[0064] (1) The trench mask plate and the ridge mask plate suitable for an 8 cm x 8 cm interdigital flow field were prepared by wire cutting, and the cutter mold suitable for an 8 cm x 8 cm carbon paper was prepared by punch forming.

[0065] The groove mask plate is cut by wire cutting on a 10 cm x 10 cm flat plate to form 40 square window spraying areas and 8 positioning holes, each square window is 80 mm long, 1 mm wide, and the spacing is 2 mm; the ridge mask plate is cut by wire cutting on a 10 cm x 10 cm flat plate to form 40 square window spraying areas and 8 positioning holes, each square window is 80 mm long, 1 mm wide, and the spacing is 2 mm, and each window is moved down by 1 mm compared with the groove mask plate. The square blade size of the carbon paper cutter is 10 cm x 10 cm, and the 8 positioning holes are consistent with the groove and ridge mask plate.

[0066] (2) 0.4 g of XC-72 carbon powder, 0.17 g of 60 wt% polytetrafluoroethylene dispersion, 0.063 g of PMMA and 40 g of anhydrous ethanol were weighed by a balance to prepare slurry I.

[0067] (3) 0.4 g of XC-72 carbon powder, 0.17 g of 60 wt% polytetrafluoroethylene dispersion and 38 g of anhydrous ethanol were weighed by a balance to prepare slurry II.

[0068] (4) The slurry I and the slurry II were heated in a 95℃ water bath for 4 min. Then the slurry I and the slurry II were ultrasonically dispersed for 2 h.

[0069] (5) The hydrophobic treated carbon paper was cut by a cutter, and the positioning holes were aligned and placed under the 8 cm x 8 cm interdigital flow field groove mask plate, and the slurry I was sprayed; after the spraying was completed, the 8 cm x 8 cm interdigital flow field ridge mask plate was replaced and the positioning holes were aligned, and the microporous layer with pore forming agent was shielded, and the slurry II was sprayed.

[0070] (6) The carbon paper with attached microporous layer after spraying was placed in a muffle furnace at 400℃ for 3 h, and finally the microporous layer with ordered pore structure was obtained, which was suitable for a 64 cm 2 interdigital flow field.

[0071] This example is based on a 64 cm 2 interdigital flow field, and 40 large-pore microporous layers and 40 regular-pore microporous layers are prepared on the surface of an 8 cm x 8 cm square carbon paper.

[0072] Figure 4 and Figure 5 show the effect of the application. From Figure 4 , it can be clearly observed that the surface of the microporous layer on the carbon paper containing the pore forming agent slurry is rough and uneven after calcination, and the pore forming agent decomposes and leaves a large number of micron-sized pores. Figure 5The micro-porous layer is a micro-porous layer of carbon paper sprayed with slurry without pore-forming agent, and the surface is relatively flat after baking, and most of the pores are nanoscale. In this way, the micro-porous layer under the groove sprayed with pore-forming agent generates a large number of pores after baking, meeting the requirements of rapid ventilation and drainage of the fuel cell; the micro-porous layer under the ridge sprayed with conventional slurry without pore-forming agent ensures its conductive performance after baking. The micro-porous layer with large pores under the groove and the micro-porous layer with conventional pores under the ridge cooperate with each other, simultaneously ensuring material transmission and electron transmission, which is conducive to improving the power density of the fuel cell.

Claims

1. A method of making an ordered-pore-structure microporous layer, characterized by: The preparation method comprises the following steps: (1) preparing a groove mask plate according to the windowing of the flow field groove structure and a ridge mask plate according to the windowing of the flow field ridge structure by a wire cutting method; preparing a carbon paper cutter die by a punching method, the carbon paper cutter die comprising a substrate, a square blade and 8 positioning hole blades, the groove mask plate and the ridge mask plate are both opened with windows for spraying slurry, and the groove mask plate and the ridge mask plate are both opened with positioning holes at the same positions and corresponding to the positioning hole blades of the carbon paper cutter die; (2) placing conductive carbon black, polytetrafluoroethylene and pore-forming agent polymethyl methacrylate in anhydrous ethanol solution to prepare slurry I containing the pore-forming agent; (3) placing conductive carbon black and polytetrafluoroethylene in anhydrous ethanol solution to prepare slurry II without the pore-forming agent; (4) using the positioning holes of the carbon paper cutter die to cut positioning holes on the hydrophobic treated carbon paper, covering the groove mask plate on the hydrophobic carbon paper by the positioning holes, spraying slurry I on the carbon paper through the windows of the groove mask plate by an ultrasonic spraying method, and then removing the groove mask plate; still covering the ridge mask plate on the carbon paper sprayed with slurry I by the positioning holes, spraying slurry II through the windows of the ridge mask plate to form a carbon paper substrate with two kinds of microporous layers; (5) placing the carbon paper sprayed with the two kinds of slurry in a muffle furnace for calcination, so that the polytetrafluoroethylene is melted and the pore-forming agent polymethyl methacrylate is decomposed, and a microporous layer with ordered pore distribution in two structural characteristics of grooves and ridges is obtained.

2. A method of preparing an ordered-pore-structure microporous layer according to claim 1, characterized by In the step (1), the groove mask plate is provided with M rectangular windows, M+1 edges and 8 positioning holes around the periphery; the ridge mask plate is provided with N rectangular windows, N+1 edges and 8 positioning holes corresponding to the groove mask plate, the rectangular windows on the groove mask plate correspond to the edges of the ridge mask plate one by one; the rectangular windows on the ridge mask plate correspond to the edges on the groove mask plate one by one, wherein the M rectangular windows correspond to the number of grooves in the flow field; the N rectangular windows correspond to the number of ridges in the flow field.

3. A method of making and processing an ordered-pore-structure microporous layer according to claim 1, characterized in that the step of In the step (2), the mass fraction of conductive carbon black in the slurry I is 40-80 wt%, the mass fraction of polytetrafluoroethylene is 10-30 wt%, the mass fraction of polymethyl methacrylate is 10-30 wt%, and the total solute mass fraction of the slurry I is 1.0-2.0 wt%; after the slurry is prepared, it is placed in a water bath for aging at 95℃ for 2-4 minutes, so that the polytetrafluoroethylene is more easily dispersed, and then the slurry I is placed in an ultrasonic cleaner for ultrasonic oscillation for 1-2 hours.

4. A method of making an ordered-pore-structure microporous layer according to claim 1, characterized by In the step (3), the mass fraction of conductive carbon black in the slurry II is 70-90 wt%, the mass fraction of polytetrafluoroethylene is 10-30 wt%, and the total solute mass fraction of the slurry is 1.0-2.0 wt%; after the slurry is prepared, it is placed in a water bath for aging at 95℃ for 2-4 minutes, so that the polytetrafluoroethylene is more easily dispersed, and then the slurry II is placed in an ultrasonic cleaner for ultrasonic oscillation for 1-2 hours.

5. A method of making an ordered-pore-structure microporous layer according to claim 1, characterized by: in the step of forming the ordered-pore-structure microporous layer, using a material having a pore diameter of 0.1 to 1.0 nm. In the step (4), the ultrasonic spraying procedures of the slurry I and the slurry II are the same, after the groove mask plate is sprayed with the slurry I, the ridge mask plate is replaced, so that the slurry I spraying area is shielded by the ridge mask plate, and then the slurry II is sprayed, the two kinds of mask plates are positioned with the positioning holes on the hydrophobic carbon paper through the positioning holes.

6. A method of making an ordered-pore-structure microporous layer according to claim 1, characterized by: In the step (5), the carbon paper sprayed with the two kinds of microporous layer slurries is baked in a muffle furnace at a temperature of 400°C for 2-3 hours.

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