A three-dimensional porous graphene composite catalyst layer membrane electrode system and a preparation method thereof

Abstract

The present invention relates to the technical field of noble metal nano-catalytic materials, and particularly to a three-dimensional porous graphene composite catalyst layer membrane electrode system and a preparation method thereof, including a membrane electrode preparation system. The membrane electrode preparation system includes a preparation stage of platinum-carbon catalyst, and a preparation stage of membrane electrode slurry is also cooperatively arranged in the preparation stage of platinum-carbon catalyst. The preparation stage of membrane electrode slurry is also cooperatively provided with a preparation stage of cathode catalyst layer and a preparation stage of anode catalyst layer. The membrane electrode preparation system further includes a membrane electrode treatment stage. Through a carefully designed preparation process, high dispersion and uniformity of the catalyst are achieved, the catalytic performance and stability of the electrode are improved. The present invention also optimizes the electrode structure, enhances the porosity and ion conduction performance, and significantly improves the efficiency and lifespan of the battery.

Description

Technical Field

[0001] The present invention relates to the technical field of noble metal nano-catalytic materials, and particularly relates to a three-dimensional porous graphene composite catalyst layer membrane electrode system and a preparation method thereof. Background Art

[0002] As a clean, efficient and sustainable new energy, hydrogen energy is regarded as the most potential next-generation energy. As an ideal way of hydrogen energy, proton exchange membrane fuel cells have the advantages of high efficiency, cleanness, low operating temperature, high energy density, etc., and are an ideal clean energy. The membrane electrode is a key component that determines the performance of the fuel cell and plays a crucial role.

[0003] The membrane electrode (Membrane Electrode Assembly, MEA) is the core component of the fuel cell and is the place where the fuel cell undergoes oxidation-reduction reactions. It mainly consists of a gas diffusion layer (Gas diffusion layer, GDL), a catalyst layer (Catalyst layer, CL), a proton exchange membrane (Proton Exchange Membrane, PEM), and a sealing layer; the catalyst layer catalyzes the electrochemical reactions of hydrogen and oxygen, and is divided into a cathode catalyst layer (oxygen reduction reaction) and an anode catalyst layer (hydrogen oxidation reaction); the anode catalyst layer decomposes hydrogen into protons and releases electrons, and the electrons reach the cathode through an external circuit; the cathode catalyst layer catalyzes the electrochemical reaction of protons and oxygen to obtain electrons and generate water.

[0004] The catalyst layer mainly has four functions. The first function is to supply the reaction gas supplied from the gas diffusion layer to the reaction sites of the catalyst layer; the second function is to conduct the necessary hydrogen ions or the generated hydrogen ions in the reaction on the electrode catalyst; the third function is to conduct the necessary electrons or the generated electrons in the reaction; the fourth function is to accelerate the electrode reaction by using high catalyst performance and its large reaction area. In short, the catalyst layer needs to have high reaction gas permeability, hydrogen ion conductivity, electron conductivity, and catalyst performance.

[0005] The existing catalyst layer has the same formula. During the process of single-cell power generation, the reaction conditions at the inlet and outlet are different. The humidity at the inlet is relatively low, and the content of hydrogen is relatively abundant. The humidity near the outlet is relatively high, and the concentration of hydrogen is relatively low. This requires that the catalyst layer at the back end has better drainage performance and more catalytic active sites. Currently, the formula of the catalyst is the same and cannot meet different requirements according to different regions. Summary of the Invention

[0006] To solve some problems existing in the above-mentioned prior art, the present invention provides a three-dimensional porous graphene composite catalyst layer membrane electrode system and a preparation method thereof to address the deficiencies in the prior art.

[0007] To achieve the above object, the present invention provides a three-dimensional porous graphene composite catalyst layer membrane electrode system, including a membrane electrode preparation system. The membrane electrode preparation system includes a platinum-carbon catalyst preparation stage, and the platinum-carbon catalyst preparation stage is also provided with a membrane electrode slurry preparation stage in cooperation. The membrane electrode slurry preparation stage is also provided with a cathode catalyst layer preparation stage and an anode catalyst layer preparation stage in cooperation. The membrane electrode preparation system also includes a membrane electrode treatment stage.

[0008] As a further improvement of the present invention, in order to help form uniform and high-performance catalyst particles, and achieve the fine preparation and performance optimization of the catalyst, the platinum-carbon catalyst preparation stage includes a unit storage tank. Inside the unit storage tank, there are several groups of storage units. On one side of the unit storage tank, there are several groups of first raw material storage tanks. The first raw material storage tanks are connected to a first mixing chamber through pipelines. The first mixing chamber is provided with a flipping type stirring tank in cooperation. The flipping type stirring tank is provided with a first transition chamber in cooperation. The first transition chamber is connected to a first ultrasonic disperser. The first ultrasonic disperser is connected to a hydrothermal reaction kettle through pipelines. The hydrothermal reaction kettle is provided with a gel cleaning chamber. On one side of the gel cleaning chamber, there is a deionized water preparation device separately arranged. The gel cleaning chamber is connected to a conductivity testing box. The conductivity testing box is provided with a freeze dryer in cooperation. After the freeze dryer, there is a tubular furnace, and the tubular furnace is also provided with a weighing sensor.

[0009] As a further improvement of the present invention, in order to ensure the uniform dispersion of the components of the slurry and be beneficial to improving the coating quality and catalytic performance of the electrode, the membrane electrode slurry preparation stage includes an ultrapure water storage tank, an alloy catalyst storage tank, an ethanol storage tank, an isopropanol storage tank, a n-propanol storage tank, an ethylene glycol storage tank, and a perfluorosulfonic acid dispersion liquid storage tank. The ultrapure water storage tank and the alloy catalyst storage tank are connected to a second mixing chamber. The ethanol storage tank, the isopropanol storage tank, the n-propanol storage tank, and the ethylene glycol storage tank are connected to a third mixing chamber. The perfluorosulfonic acid dispersion liquid storage tank is provided with a fourth mixing chamber. The second mixing chamber, the third mixing chamber, and the fourth mixing chamber are connected to each other through pipelines. The fourth mixing chamber is connected to a second ultrasonic disperser and a stirring reaction kettle. The stirring reaction kettle is connected to a second raw material storage tank through pipelines.

[0010] As a further improvement of the present invention, in order to ensure the uniform distribution and firm adhesion of the catalyst, and improve the catalytic activity and stability of the electrode, the preparation stage of the cathode catalyst layer includes a medium heating box, which is cooperatively provided with a process water tank, the process water tank is cooperatively provided with a heating table, the heating table is cooperatively provided with a first multi-roll conveyor belt, and the multi-roll conveyor belt is connected to a first slot coater; the preparation stage of the anode catalyst layer includes a porous carbon plate dressing platform, the porous carbon plate dressing platform is connected to a second slot coater, and the porous carbon plate dressing platform is cooperatively provided with a second multi-roll conveyor belt.

[0011] As a further improvement of the present invention, in order to help optimize the microstructure of the electrode and further improve the catalytic efficiency and battery performance, the membrane electrode treatment stage includes a film tensioning area, which is cooperatively provided with a hot press, a cold press is arranged behind the hot press, and a third multi-roll conveyor belt is arranged behind the cold press.

[0012] The present invention provides a three-dimensional porous graphene composite catalyst layer membrane electrode system, and the beneficial effects of this system are reflected in the following aspects:

[0013] Improve catalytic performance:

[0014] Through the carefully designed preparation stage of the platinum-carbon catalyst, the present invention can prepare a platinum-carbon catalyst with high dispersibility and uniformity. This catalyst has more active sites and better catalytic activity, thus significantly improving the catalytic performance of the electrode. Optimize the electrode structure:

[0015] The fine design of the layer membrane electrode slurry preparation stage ensures the uniform and stable composition of the slurry. By precisely controlling the proportion and mixing conditions of various raw materials, a slurry with ideal viscosity and fluidity can be prepared. The optimized electrode structure has a higher porosity and better ion conduction performance, which helps to improve the performance and stability of the battery.

[0016] Enhance electrode stability:

[0017] The preparation stage of the cathode and anode catalyst layers adopts advanced coating technologies, such as slot coaters, to ensure the uniformity and consistency of the catalyst layers. At the same time, by precisely controlling the heating and cooling conditions, the mechanical strength and durability of the electrode can be further enhanced. This enhanced stability enables the electrode to maintain stable performance during long-term use and extends the service life of the battery.

[0018] Improve battery efficiency:

[0019] The settings in the membrane electrode treatment stage, including steps such as membrane material tensioning, hot pressing, and cold pressing, help optimize the microstructure of the electrode, reduce internal resistance, and improve the power density and efficiency of the battery. These treatment steps can also ensure the tight bonding between electrode layers, prevent problems such as delamination or peeling during use, thereby improving the reliability and safety of the battery.

[0020] A preparation method of a three-dimensional porous graphene composite catalyst layer membrane electrode system, the preparation method comprising the following steps:

[0021] Step 1: Prepare a graphite oxide solution, prepare a graphite oxide suspension solution with a certain concentration, transport the graphite oxide solution to several storage units in a unit storage tank, first mix ultrapure water and the graphite oxide solution in a first mixing chamber, and detect the concentration of the mixed solution;

[0022] Step 2: Mix the mixed solution obtained in Step 1 with a hydrogen fuel electrocatalyst in another first mixing chamber, add a small amount of NiCl·H₂O solution, and perform re-mixing to obtain a mixed solution;

[0023] Step 3: Transport the mixed solution obtained in Step 2 into a tumbling stirrer for stirring and mixing, send the mixed solution into a transition chamber for detecting the concentration of the mixed solution, and after the detection is completed, send the mixed solution into a first ultrasonic disperser for ultrasonic stirring at room temperature;

[0024] Step 4: Transfer the mixed solution to a hydrothermal reaction kettle for hydrothermal reaction. After waiting for the temperature of the reaction kettle to cool to room temperature, transfer the gel obtained from the reaction to a gel cleaning chamber for cleaning, and timely replenish water through a deionized water preparation device;

[0025] Step 5: The product after cleaning enters a conductivity test box. Through conductivity testing, the purity and ion content of the product are detected. The product after conductivity testing is transported to a freeze dryer, and in the freeze dryer, through low-temperature freezing and vacuum drying treatment, the moisture and solvent in the product are removed to obtain a dry platinum-carbon composite;

[0026] Step 6: The dried platinum-carbon composite enters a tube furnace for heat treatment. The heat treatment can further improve the structure and performance of the platinum-carbon composite. A weighing sensor is provided behind the tube furnace for accurately weighing the product after heat treatment;

[0027] Step 7: Ensure that sufficient raw materials are stored in the ultrapure water storage tank, alloy catalyst storage tank, ethanol storage tank, isopropanol storage tank, n-propanol storage tank, ethylene glycol storage tank, and perfluorosulfonic acid dispersion storage tank respectively;

[0028] Step Eight: Transfer ultrapure water from the ultrapure water storage tank to the second mixing chamber through a pipeline, and transfer the alloy catalyst from the alloy catalyst storage tank to the second mixing chamber through a pipeline; in the second mixing chamber, the ultrapure water and the alloy catalyst are preliminarily mixed;

[0029] Step Nine: Transfer the raw materials in the ethanol storage tank, isopropanol storage tank, n-propanol storage tank and ethylene glycol storage tank to the third mixing chamber through pipelines. In the third mixing chamber, the above four alcohol raw materials are preliminarily mixed and mixed with the mixed solution in Step Eight;

[0030] Step Ten: Transfer the perfluorosulfonic acid dispersion from the perfluorosulfonic acid dispersion storage tank to the fourth mixing chamber through a pipeline, and mix the mixed solution obtained in Step Eight with the perfluorosulfonic acid dispersion in the fourth mixing chamber;

[0031] Step Eleven: Transfer the final mixed solution obtained in Step Ten to the second ultrasonic disperser. After the dispersion is completed, transfer the mixed solution to a stirring reaction kettle for stirring and mixing and add carbon black. After the stirring is completed, transfer the uniformly mixed slurry to the second raw material storage tank for storage;

[0032] Step Twelve: Preheat the medium heating box to reach the required temperature range to provide a stable heat source for subsequent process steps. Fill the process water tank with an appropriate amount of process water, and these process waters will be heated through a heating table to reach the temperature conditions required for coating;

[0033] Step Thirteen: Start the heating table, heat the process water in the process water tank to a predetermined temperature, and transfer the heated process water or other coating media to the first multi-roll conveyor belt through a pipeline. The multi-roll conveyor belt runs at a stable rate to ensure that the coating media is evenly distributed on the conveyor belt;

[0034] Step Fourteen: When the coating media is evenly distributed on the first multi-roll conveyor belt, the first slot coater starts to work. The slot coater evenly coats the coating media on the conveyor belt, such as a proton exchange membrane, through a precisely controlled slot to form a precursor of the cathode catalyst layer;

[0035] Step Fifteen: After the coating is completed, the substrate material is dried through a hot air device, and the dried precursor of the cathode catalyst layer enters the next process step;

[0036] Step Sixteen: On the porous carbon plate dressing platform, prepare the required porous carbon plates and coating media. The second slot coater evenly coats the coating media on the porous carbon plates through a precisely controlled slot. After the coating is completed, the porous carbon plates are conveyed through the second multi-roll conveyor belt;

[0037] Step Seventeen: During the conveying process, hot air drying is carried out. After the coating is completed and the catalyst layer is completely dried, the preparation of the anode catalyst layer is completed. The processed anode catalyst layer is transferred to the next process for assembly;

[0038] Step Eighteen: Feed the membrane material into the tensioning area. In this area, the membrane material will be tightened by the tensioning device. After the membrane material is tensioned, it enters the hot press area. The hot press applies high temperature and pressure to perform hot pressing on the membrane material;

[0039] Step Nineteen: After the hot pressing treatment, the membrane material enters the cold press area. The cold press further processes the membrane material by applying pressure at a lower temperature. After the membrane material is cold pressed, it enters the third multi-roller conveyor belt area. On the third multi-roller conveyor belt, the membrane material will be further flattened and compacted by the rolling action of multiple rollers;

[0040] Step Twenty: The cooling device on the conveyor belt quickly cools the membrane material to room temperature, and the cold-pressed membrane electrode is sealed and stored.

[0041] The present invention provides a preparation method for a three-dimensional porous graphene composite catalyst layer membrane electrode system. The beneficial effects of this preparation method are reflected in the following aspects:

[0042] Precise concentration control and mixing:

[0043] In the initial stage of preparation, by precisely detecting the concentration of the graphite oxide solution and mixing it with the hydrogen fuel electrocatalyst, NiCl·HO solution, etc., the accurate ratio of reactants is ensured, thereby improving the quality and performance of the final product. The setting of multiple mixing bins and detection links makes the entire mixing process more controllable and reduces the problem of unstable product performance caused by concentration fluctuations.

[0044] Effective dispersion and reaction:

[0045] Using an ultrasonic disperser and a flipping stirrer to disperse and stir the mixed solution effectively improves the dispersion uniformity of the reactants, enabling the catalyst to be more evenly distributed on the surface of graphene and improving the catalytic efficiency. The use of a hydrothermal reaction kettle provides a high-temperature and high-pressure reaction environment for the mixed solution, which helps the tight combination between the catalyst and graphene and forms a stable three-dimensional porous structure.

[0046] Strict purity and conductivity control:

[0047] By using a conductivity test box to detect the purity and ion content of the product, it is ensured that the conductivity performance of the product meets the requirements, which is crucial for improving the conductivity and catalytic performance of the electrode. The introduction of a cleaning and deionized water preparation device effectively removes impurities and residual solvents in the product and improves the purity of the product.

[0048] Heat treatment and precise weighing:

[0049] The heat treatment step of the tubular furnace further improves the structure and performance of the platinum-carbon composite, endowing it with better catalytic activity and stability. The setting of the weighing sensor ensures the precise weighing of the product after heat treatment, providing accurate data support for subsequent processes.

[0050] Multi-component mixing and coating process:

[0051] Through the coordinated use of multiple storage tanks and mixing bins, precise proportioning and mixing of various raw materials are achieved, providing a guarantee for the preparation of high-performance composite catalysts. The use of a slot coater ensures the uniform coating of the coating medium, making the catalyst layer more evenly distributed on the substrate material and improving the performance and stability of the electrode.

[0052] Improved post-treatment process:

[0053] The tensioning, hot pressing and cold pressing treatments of the membrane material effectively remove bubbles and defects in the membrane material, improving the flatness and compactness of the membrane electrode. The setting of the cooling device ensures that the membrane material will not deform or crack due to temperature changes during the cooling process, guaranteeing the quality of the membrane electrode.

[0054] When the present invention works, first, in the unit storage tank, the graphite oxide solution and ultrapure water are mixed in the first mixing bin; then the hydrogen fuel electrocatalyst and NiCl·HO solution are added for secondary mixing to form a uniform mixture; the mixture is sent into a tumbling agitator tank for sufficient stirring to ensure the uniform dispersion of each component; then the mixture enters the first ultrasonic disperser and is ultrasonically stirred at room temperature to further promote the uniformity of the mixture; the mixture after ultrasonic dispersion is transferred to a hydrothermal reaction kettle for hydrothermal reaction; after the reaction is completed, the obtained gel is sent into the gel cleaning chamber for cleaning to remove impurities; during the cleaning process, the deionized water preparation device provides a continuous supply of deionized water to the cleaning chamber; the cleaned gel enters the conductivity test box for detection to ensure that the purity and ion content of the product meet the requirements; then the product is sent into a freeze dryer for low-temperature freezing and vacuum drying treatments to remove moisture and solvents; the dried platinum-carbon composite enters the tubular furnace for heat treatment to further improve its structure and performance; the weighing sensor set behind the tubular furnace is used to precisely measure the weight of the product after heat treatment.

[0055] Raw materials are taken out from the ultrapure water storage tank, alloy catalyst storage tank, and various alcohol storage tanks, and are preliminarily mixed in the second mixing bin and the third mixing bin respectively; subsequently, the perfluorosulfonic acid dispersion is taken out from the perfluorosulfonic acid dispersion storage tank and is finally mixed with the previous mixed liquid in the fourth mixing bin; the final mixed liquid is sent to the second ultrasonic disperser for ultrasonic dispersion treatment to ensure uniform dispersion of each component; after that, the mixed liquid enters the stirring reaction kettle for stirring and mixing to form a uniform layer film electrode paste; after stirring is completed, the paste is sent to the second raw material storage tank for storage and standby.

[0056] The dielectric heating box and the process water tank are preheated to the required temperature; the heated process water or other coating media are transported to the first multi-roll conveyor belt; the first slot coater uniformly coats the coating media on the proton exchange membrane through a precisely controlled slot to form a precursor of the cathode catalyst layer; after coating is completed, the precursor is cured into the cathode catalyst layer through hot air drying treatment; the porous carbon plate and the coating media are prepared on the porous carbon plate dressing platform; the second slot coater uniformly coats the coating media on the porous carbon plate through a precisely controlled slot to form a precursor of the anode catalyst layer; after coating is completed, hot air drying treatment is also carried out to cure the anode catalyst layer.

[0057] The prepared film material is sent to the tensioning area for tensioning treatment to ensure its flatness; subsequently, the film material enters the hot press area for hot pressing treatment under high temperature and high pressure to enhance its structure and performance; the film material after hot pressing treatment enters the cold press area for further treatment at a lower temperature to enhance its stability; after that, the film material is leveled and compacted on the third multi-roll conveyor belt to ensure the flatness of its surface and the tightness of its internal structure; finally, the film material is quickly cooled to room temperature using a cooling device and is sealed for storage. Description of the Drawings

[0058] For the convenience of those skilled in the art to understand, the present invention will be further described below in conjunction with the drawings:

[0059] Figure 1 It is a structural diagram of the preparation stage of the platinum-carbon catalyst of the present invention.

[0060] Figure 2 It is a structural diagram of the preparation stage of the layer film electrode paste of the present invention.

[0061] Figure 3 It is a structural diagram of the preparation stage of the cathode catalyst layer of the present invention.

[0062] Figure 4 It is a structural diagram of the preparation stage of the anode catalyst layer of the present invention.

[0063] Figure 5 It is a structural diagram of the membrane electrode treatment stage of the present invention.

[0064] Among them, 1 platinum-carbon catalyst preparation stage, 2 layer membrane electrode slurry preparation stage, 3 cathode catalyst layer preparation stage, 4 anode catalyst layer preparation stage, 5 membrane electrode treatment stage, 6 unit storage tank, 7 first raw material storage tank, 8 first mixing bin, 9 tilting agitator tank, 10 first transition bin, 11 first ultrasonic disperser, 12 hydrothermal reactor, 13 gel cleaning chamber, 14 deionized water preparation device, 15 conductivity test box, 16 freeze dryer, 17 tube furnace, 18 load cell, 19 ultrapure water storage tank, 20 alloy catalyst storage tank, 21 ethanol storage tank, 22 isopropanol storage tank, 23 n-propanol storage tank, 24 ethylene glycol storage tank, 25 perfluorosulfonic acid dispersion storage tank, 26 second mixing bin, 27 third mixing bin, 28 fourth mixing bin, 29 second ultrasonic disperser, 30 stirring reactor, 31 second raw material storage tank, 32 medium heating box, 33 process water tank, 34 heating table, 35 first multi-roll conveyor belt, 36 first slot coater, 37 porous carbon plate dressing platform, 38 second slot coater, 39 second multi-roll conveyor belt, 40 film tensioning area, 41 hot press, 42 cold press, 43 third multi-roll conveyor belt. Detailed implementation mode

[0065] In order to enable those skilled in the art to better understand the technical solutions in this application, the following combines the attached Figures 1-5 The present invention is further described. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and cannot be used to limit the protection scope of the present invention.

[0066] As Figures 1-5 shown, a three-dimensional porous graphene composite catalyst layer membrane electrode system includes a layer membrane electrode preparation system. The layer membrane electrode preparation system includes a platinum-carbon catalyst preparation stage 1, and the platinum-carbon catalyst preparation stage 1 is also cooperatively provided with a layer membrane electrode slurry preparation stage 2. The layer membrane electrode slurry preparation stage 2 is also cooperatively provided with a cathode catalyst layer preparation stage 3 and an anode catalyst layer preparation stage 4. The layer membrane electrode preparation system also includes a membrane electrode treatment stage 5.

[0067] The preparation stage 1 of the platinum-carbon catalyst includes a unit storage tank 6, inside which there are several groups of material storage units. On one side of the unit storage tank 6, there are several groups of first raw material storage tanks 7. The first raw material storage tanks 7 are connected to a first mixing bin 8 through pipelines. The first mixing bin 8 is equipped with a flip-type stirring tank 9 in cooperation. The flip-type stirring tank 9 is equipped with a first transition bin 10 in cooperation. The first transition bin 10 is connected to a first ultrasonic disperser 11. The first ultrasonic disperser 11 is connected to a hydrothermal reaction kettle 12 through pipelines. The hydrothermal reaction kettle 12 is provided with a gel cleaning chamber 13. On one side of the gel cleaning chamber 13, there is a deionized water preparation device 14 separately. The gel cleaning chamber 13 is connected to a conductivity test box 15. The conductivity test box 15 is equipped with a freeze dryer 16 in cooperation. After the freeze dryer 16, there is a tubular furnace 17. The tubular furnace 17 is also provided with a weighing sensor 18.

[0068] The preparation stage 2 of the layer film electrode slurry includes an ultrapure water storage tank 19, an alloy catalyst storage tank 20, an ethanol storage tank 21, an isopropanol storage tank 22, a n-propanol storage tank 23, an ethylene glycol storage tank 24, and a perfluorosulfonic acid dispersion storage tank 25. The ultrapure water storage tank 19 and the alloy catalyst storage tank 20 are connected to a second mixing bin 26. The ethanol storage tank 21, the isopropanol storage tank 22, the n-propanol storage tank 23, and the ethylene glycol storage tank 24 are connected to a third mixing bin 27. The perfluorosulfonic acid dispersion storage tank 25 is provided with a fourth mixing bin 28. The second mixing bin 26, the third mixing bin 27, and the fourth mixing bin 28 are connected to each other through pipelines. The fourth mixing bin 28 is connected to a second ultrasonic disperser 29 and a stirring reaction kettle 30. The stirring reaction kettle 30 is connected to a second raw material storage tank 31 through pipelines.

[0069] The preparation stage 3 of the cathode catalyst layer includes a dielectric heating box 32, which is equipped with a process water tank 33 in cooperation. The process water tank 33 is equipped with a heating table 34 in cooperation. The heating table 34 is equipped with a first multi-roller conveyor belt 35 in cooperation. The multi-roller conveyor belt is connected to a first slot coater 36. The preparation stage 4 of the anode catalyst layer includes a porous carbon plate dressing platform 37, which is connected to a second slot coater 38. The porous carbon plate dressing platform 37 is equipped with a second multi-roller conveyor belt 39 in cooperation.

[0070] The membrane electrode treatment stage 5 includes a membrane material tensioning area 40, which is equipped with a hot press 41 in cooperation. After the hot press 41, there is a cold press 42. After the cold press 42, there is a third multi-roller conveyor belt 43.

[0071] A preparation method of a three-dimensional porous graphene composite catalyst layer membrane electrode system, the preparation method comprising the following steps:

[0072] Step 1: Prepare a graphene oxide solution to form a graphene oxide suspension solution with a certain concentration. Transport the graphene oxide solution to several storage units in the unit storage tank 6. First, mix ultrapure water and the graphene oxide solution in the first mixing chamber 8, and detect the concentration of the mixed solution.

[0073] Step 2: Mix the mixed solution obtained in Step 1 with a hydrogen fuel electrocatalyst in another first mixing chamber 8, add a small amount of NiCl2·6H2O solution, and mix again to obtain a mixed solution.

[0074] Step 3: Transport the mixed solution obtained in Step 2 into a tilting stirrer for stirring and mixing. Send the mixed solution into the transition chamber for detecting the concentration of the mixed solution. After the detection is completed, send the mixed solution into the first ultrasonic disperser 11 for ultrasonic stirring at room temperature.

[0075] Step 4: Transfer the mixed solution to the hydrothermal reaction kettle 12 for hydrothermal reaction. After the temperature of the reaction kettle cools down to room temperature, transfer the gel obtained from the reaction to the gel cleaning chamber 13 for cleaning, and timely replenish water through the deionized water preparation device 14.

[0076] Step 5: The washed product enters the conductivity test box 15. Through conductivity testing, detect the purity and ion content of the product. The product after conductivity testing is transported to the freeze dryer 16. In the freeze dryer 16, through low-temperature freezing and vacuum drying treatment, remove the moisture and solvent in the product to obtain a dry platinum-carbon composite.

[0077] Step 6: The dried platinum-carbon composite enters the tube furnace 17 for heat treatment. Heat treatment can further improve the structure and performance of the platinum-carbon composite. A weighing sensor 18 is arranged behind the tube furnace 17 for accurately weighing the product after heat treatment.

[0078] Step 7: Ensure that there are sufficient raw materials stored in the ultrapure water storage tank 19, alloy catalyst storage tank 20, ethanol storage tank 21, isopropanol storage tank 22, n-propanol storage tank 23, ethylene glycol storage tank 24, and perfluorosulfonic acid dispersion storage tank 25 respectively.

[0079] Step 8: Transport ultrapure water from the ultrapure water storage tank 19 to the second mixing chamber 26 through a pipeline, and transport the alloy catalyst from the alloy catalyst storage tank 20 to the second mixing chamber 26 through a pipeline; in the second mixing chamber 26, the ultrapure water and the alloy catalyst are preliminarily mixed.

[0080] Step Nine: Transfer the raw materials in the ethanol storage tank 21, isopropanol storage tank 22, n-propanol storage tank 23, and ethylene glycol storage tank 24 to the third mixing bin 27 through pipelines. In the third mixing bin 27, the above four alcohol raw materials are preliminarily mixed and mixed with the mixed liquid in Step Eight;

[0081] Step Ten: Transfer the perfluorosulfonic acid dispersion from the perfluorosulfonic acid dispersion storage tank 25 to the fourth mixing bin 28 through a pipeline, and mix the mixed liquid obtained in Step Eight with the perfluorosulfonic acid dispersion in the fourth mixing bin 28;

[0082] Step Eleven: Transfer the final mixed liquid obtained in Step Ten to the second ultrasonic disperser 29 for dispersion. After the dispersion is completed, transfer the mixed liquid to the stirring reaction kettle 30 for stirring and mixing, and add carbon black. After the stirring is completed, transfer the uniformly mixed slurry to the second raw material storage tank 31 for storage;

[0083] Step Twelve: Preheat the medium heating box 32 to reach the required temperature range to provide a stable heat source for subsequent process steps. Fill the process water tank 33 with an appropriate amount of process water, and these process waters will be heated by the heating table 34 to reach the temperature conditions required for coating;

[0084] Step Thirteen: Start the heating table 34 to heat the process water in the process water tank 33 to the predetermined temperature. The heated process water or other coating media are transported to the first multi-roll conveyor belt 35 through pipelines, and the multi-roll conveyor belt runs at a stable rate to ensure that the coating media are evenly distributed on the conveyor belt;

[0085] Step Fourteen: When the coating media are evenly distributed on the first multi-roll conveyor belt 35, the first slot coater 36 starts to work. The slot coater evenly coats the coating media on the conveyor belt, such as a proton exchange membrane, through a precisely controlled slot to form a precursor of the cathode catalyst layer;

[0086] Step Fifteen: After the coating is completed, the substrate material is dried by a hot air device, and the dried precursor of the cathode catalyst layer enters the next process step;

[0087] Step Sixteen: On the porous carbon plate dressing platform 37, prepare the required porous carbon plates and coating media. The second slot coater 38 evenly coats the coating media on the porous carbon plates through a precisely controlled slot. After the coating is completed, the porous carbon plates are transported by the second multi-roll conveyor belt 39;

[0088] Step Seventeen: Conduct hot air drying during the transportation process. After the catalyst layer is completely dried after the coating is completed, the anode catalyst layer is prepared, and the processed anode catalyst layer is transferred to the next process for assembly;

[0089] Step Eighteen: Feed the film material into the tensioning area. In this area, the film material will be tightened by the tensioning device. After being tensioned, the film material enters the area of the hot press 41. The hot press 41 performs hot pressing on the film material by applying high temperature and pressure.

[0090] Step Nineteen: After being hot-pressed, the film material enters the area of the cold press 42. The cold press 42 further processes the film material by applying pressure and at a relatively low temperature. After being cold-pressed, the film material enters the area of the third multi-roller conveyor belt 43. On the third multi-roller conveyor belt 43, the film material will be further flattened and compacted by the rolling action of multiple rollers.

[0091] Step Twenty: The cooling device on the conveyor belt quickly cools the film material to room temperature, and the cold-pressed membrane electrode is sealed and stored.

[0092] When the present invention works, first in the unit storage tank 6, the graphite oxide solution and ultrapure water are mixed in the first mixing chamber 8; then a hydrogen fuel electrocatalyst and a NiCl2·6H2O solution are added for secondary mixing to form a uniform mixed solution; the mixed solution is fed into the flip-type stirring tank 9 for sufficient stirring to ensure that each component is evenly dispersed; then the mixed solution enters the first ultrasonic disperser 11, where ultrasonic stirring is carried out at room temperature to further promote the uniformity of the mixed solution; the mixed solution after ultrasonic dispersion is transferred to the hydrothermal reaction kettle 12 for hydrothermal reaction; after the reaction is completed, the obtained gel is fed into the gel cleaning chamber 13 for cleaning to remove impurities; during the cleaning process, the deionized water preparation device 14 provides a continuous supply of deionized water to the cleaning chamber; the cleaned gel enters the conductivity test box 15 for detection to ensure that the purity and ion content of the product meet the requirements; then the product is fed into the freeze dryer 16 for low-temperature freezing and vacuum drying treatment to remove moisture and solvents; the dried platinum-carbon composite enters the tubular furnace 17 for heat treatment to further improve its structure and performance; the weighing sensor 18 arranged behind the tubular furnace 17 is used to accurately measure the weight of the product after heat treatment.

[0093] Raw materials are taken out from the ultrapure water storage tank 19, the alloy catalyst storage tank 20, and various alcohol storage tanks, and are preliminarily mixed in the second mixing chamber 26 and the third mixing chamber 27 respectively; then the perfluorosulfonic acid dispersion liquid is taken out from the perfluorosulfonic acid dispersion liquid storage tank 25 and is finally mixed with the previous mixed solution in the fourth mixing chamber 28; the final mixed solution is fed into the second ultrasonic disperser 29 for ultrasonic dispersion treatment to ensure that each component is evenly dispersed; then the mixed solution enters the stirring reaction kettle 30 for stirring and mixing to form a uniform layer membrane electrode slurry; after stirring is completed, the slurry is fed into the second raw material storage tank 31 for storage and standby.

[0094] The dielectric heating tank 32 and the process water tank 33 are preheated to the required temperature; the heated process water or other coating media are transported onto the first multi-roller conveyor belt 35; the first slot coater 36 uniformly coats the coating media on the proton exchange membrane through a precisely controlled slot to form a precursor of the cathode catalyst layer; after coating, the precursor is cured into the cathode catalyst layer through hot air drying treatment; the porous carbon plate and the coating media are prepared on the porous carbon plate dressing platform 37; the second slot coater 38 uniformly coats the coating media on the porous carbon plate through a precisely controlled slot to form a precursor of the anode catalyst layer; after coating, hot air drying treatment is also carried out to cure the anode catalyst layer.

[0095] The prepared film material is sent to the tensioning area for tensioning treatment to ensure its flatness; then the film material enters the hot press 41 area for hot pressing treatment under high temperature and high pressure to enhance its structure and performance; the film material after hot pressing treatment enters the cold press 42 area for further treatment at a lower temperature to enhance its stability; then the film material is leveled and compacted on the third multi-roller conveyor belt 43 to ensure the flatness of its surface and the tightness of its internal structure; finally, the film material is quickly cooled to room temperature using a cooling device and sealed for storage.

[0096] The present invention is not limited to the above embodiments. Based on the technical solutions disclosed in the present invention, those skilled in the art can make some substitutions and deformations to some of the technical features without creative labor according to the disclosed technical content, and these substitutions and deformations are within the protection scope of the present invention.

Claims

1. A three-dimensional porous graphene composite catalyst layer membrane electrode system, including a membrane electrode preparation system, characterized in that, The membrane electrode preparation system includes a platinum-carbon catalyst preparation stage (1), and a membrane electrode slurry preparation stage (2) is also arranged in cooperation with the platinum-carbon catalyst preparation stage (1). A cathode catalyst layer preparation stage (3) and an anode catalyst layer preparation stage (4) are also arranged in cooperation with the membrane electrode slurry preparation stage (2). The membrane electrode preparation system also includes a membrane electrode treatment stage (5); The platinum-carbon catalyst preparation stage (1) includes a unit storage tank (6). A number of storage units are arranged inside the unit storage tank (6). A number of first raw material storage tanks (7) are arranged on one side of the unit storage tank (6). The first raw material storage tanks (7) are connected to a first mixing bin (8) through pipelines. A flip-type stirring tank (9) is arranged in cooperation with the first mixing bin (8). A first transition bin (10) is arranged in cooperation with the flip-type stirring tank (9). The first transition bin (10) is connected to a first ultrasonic disperser (11). The first ultrasonic disperser (11) is connected to a hydrothermal reaction kettle (12) through pipelines. A gel cleaning chamber (13) is arranged in the hydrothermal reaction kettle (12). A deionized water preparation device (14) is separately arranged on one side of the gel cleaning chamber (13). The gel cleaning chamber (13) is connected to a conductivity test box (15). A freeze dryer (16) is arranged in cooperation with the conductivity test box (15). A tube furnace (17) is arranged behind the freeze dryer (16). A weighing sensor (18) is also arranged in the tube furnace (17); The cathode catalyst layer preparation stage (3) includes a medium heating box (32). A process water tank (33) is arranged in cooperation with the medium heating box (32). A heating table (34) is arranged in cooperation with the process water tank (33). A first multi-roller conveyor belt (35) is arranged in cooperation with the heating table (34). The multi-roller conveyor belt is connected to a first slot coater (36); The anode catalyst layer preparation stage (4) includes a porous carbon plate dressing platform (37). The porous carbon plate dressing platform (37) is connected to a second slot coater (38). A second multi-roller conveyor belt (39) is arranged in cooperation with the porous carbon plate dressing platform (37).

2. The three-dimensional porous graphene composite catalyst layer membrane electrode system according to claim 1, characterized in that The preparation stage (2) of the membrane electrode paste includes an ultrapure water storage tank (19), an alloy catalyst storage tank (20), an ethanol storage tank (21), an isopropanol storage tank (22), a n-propanol storage tank (23), an ethylene glycol storage tank (24), and a perfluorosulfonic acid dispersion storage tank (25). A second mixing chamber (26) is connected to the ultrapure water storage tank (19) and the alloy catalyst storage tank (20). A third mixing chamber (27) is connected to the ethanol storage tank (21), the isopropanol storage tank (22), the n-propanol storage tank (23), and the ethylene glycol storage tank (24). A fourth mixing chamber (28) is provided in the perfluorosulfonic acid dispersion storage tank (25). The second mixing chamber (26), the third mixing chamber (27), and the fourth mixing chamber (28) are connected to each other through pipelines. The fourth mixing chamber (28) is connected to a second ultrasonic disperser (29) and a stirring reactor (30). The stirring reactor (30) is connected to a second raw material storage tank (31) through a pipeline.

3. A three-dimensional porous graphene composite catalyst layer membrane electrode system according to claim 1, characterized in that The membrane electrode treatment stage (5) includes a membrane material tensioning area (40). A hot press (41) is arranged in cooperation with the membrane material tensioning area (40). A cold press (42) is arranged behind the hot press (41). A third multi-roller conveyor belt (43) is arranged behind the cold press (42).

4. The preparation method of a three-dimensional porous graphene composite catalyst layer membrane electrode system according to claim 1, characterized in that, The preparation method includes the following steps: Step 1: Prepare a graphite oxide solution and make it into a graphite oxide suspension solution with a certain concentration. Transport the graphite oxide solution to the storage units in several groups in the unit storage tank (6). First, mix ultrapure water and the graphite oxide solution in the first mixing chamber (8), and detect the concentration of the mixed solution. Step 2: Mix the mixed solution obtained in Step 1 with a hydrogen fuel electrocatalyst in another group of the first mixing chamber (8), add a small amount of NiCl2·6H2O solution, and mix again to obtain a mixed solution. Step 3: Transport the mixed solution obtained in Step 2 into a rotary stirrer for stirring and mixing. Send the mixed solution into the transition chamber for detecting the concentration of the mixed solution. After the detection is completed, send the mixed solution into the first ultrasonic disperser (11) for ultrasonic stirring at room temperature. Step 4: Transfer the mixed solution to a hydrothermal reaction kettle (12) for hydrothermal reaction. After waiting for the temperature of the reaction kettle to cool down to room temperature, transfer the gel obtained from the reaction to the gel cleaning chamber (13) for cleaning, and timely replenish water through the deionized water preparation device (14). Step 5: The product after cleaning enters the conductivity test box (15). Through conductivity testing, detect the purity and ion content of the product. The product after conductivity testing is transported to a freeze dryer (16). In the freeze dryer (16), through low-temperature freezing and vacuum drying treatment, remove the water and solvent in the product to obtain a dry platinum-carbon composite. Step 6: The dried platinum-carbon composite enters a tube furnace (17) for heat treatment. The heat treatment can further improve the structure and performance of the platinum-carbon composite. A weighing sensor (18) is arranged behind the tube furnace (17) for accurately weighing the product after heat treatment. Step Seven: Ensure that there is sufficient raw material stored in the ultrapure water storage tank (19), alloy catalyst storage tank (20), ethanol storage tank (21), isopropanol storage tank (22), n-propanol storage tank (23), ethylene glycol storage tank (24), and perfluorosulfonic acid dispersion storage tank (25) respectively; Step Eight: Transport ultrapure water from the ultrapure water storage tank (19) to the second mixing chamber (26) through a pipeline, and transport the alloy catalyst from the alloy catalyst storage tank (20) to the second mixing chamber (26) through a pipeline; in the second mixing chamber (26), the ultrapure water and the alloy catalyst are preliminarily mixed; Step Nine: Transport the raw materials in the ethanol storage tank (21), isopropanol storage tank (22), n-propanol storage tank (23), and ethylene glycol storage tank (24) to the third mixing chamber (27) through a pipeline. In the third mixing chamber (27), the above four kinds of alcohol raw materials are preliminarily mixed and mixed with the mixed liquid in Step Eight; Step Ten: Transport the perfluorosulfonic acid dispersion from the perfluorosulfonic acid dispersion storage tank (25) to the fourth mixing chamber (28) through a pipeline, and mix the mixed liquid obtained in Step Eight with the perfluorosulfonic acid dispersion in the fourth mixing chamber (28); Step Eleven: Transfer the final mixed liquid obtained in Step Ten to the second ultrasonic disperser (29) for dispersion. After the dispersion is completed, send the mixed liquid into the stirring reaction kettle (30) for stirring and mixing, and add carbon black. After the stirring is completed, transport the uniformly mixed slurry to the second raw material storage tank (31) for storage; Step Twelve: Preheat the medium heating box (32) to reach the required temperature range to provide a stable heat source for subsequent process steps. Fill the process water tank (33) with an appropriate amount of process water, and these process waters will be heated through the heating table (34) to reach the temperature conditions required for coating; Step Thirteen: Start the heating table (34) to heat the process water in the process water tank (33) to a predetermined temperature. The heated process water or other coating media are transported to the first multi-roll conveyor belt (35) through a pipeline. The multi-roll conveyor belt runs at a stable rate to ensure that the coating media are evenly distributed on the conveyor belt; Step Fourteen: When the coating media are evenly distributed on the first multi-roll conveyor belt (35), the first slot coater (36) starts to work. The slot coater evenly coats the coating media on a proton exchange membrane or the like on the conveyor belt through a precisely controlled slot to form a precursor of the cathode catalyst layer; Step Fifteen: After the coating is completed, the substrate material is dried by a hot air device. The dried precursor of the cathode catalyst layer enters the next process step; Step Sixteen: On the porous carbon plate dressing platform (37), prepare the required porous carbon plates and coating media. The second slot coater (38) evenly coats the coating media on the porous carbon plates through a precisely controlled slot. After the coating is completed, the porous carbon plates are transported through the second multi-roll conveyor belt (39); Step Seventeen: During the transportation process, hot air drying is carried out. After the catalyst layer is completely dried after the coating is completed, the anode catalyst layer is prepared. The processed anode catalyst layer is transferred to the next process for assembly; Step Eighteen: Feed the film material into the tensioning area. In this area, the film material will be tightened by the tensioning device. After the film material is tensioned, it enters the area of the hot press (41). The hot press (41) performs hot pressing treatment on the film material by applying high temperature and pressure. Step Nineteen: After the hot pressing treatment, the film material enters the area of the cold press (42). The cold press (42) further processes the film material by applying pressure and at a relatively low temperature. After the film material is cold pressed, it enters the area of the third multi-roller conveyor belt (43). On the third multi-roller conveyor belt (43), the film material will be further flattened and compacted by the rolling action of multiple rollers. Step Twenty: The cooling device on the conveyor belt quickly cools the film material to room temperature, and the cold-pressed membrane electrode is sealed and stored.

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