Preparation method of anti-antipolar gas diffusion layer and anti-antipolar gas diffusion layer
The anti-reverse catalyst is uniformly distributed in the anti-reverse gas diffusion layer by electrophoresis, which solves the problem of uneven coating and binder hindering water and gas transmission in the prior art, and achieves efficient distribution and performance improvement of the catalyst.
Patent Information
- Application Number
- CN202411690998.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-25
- Publication Date
- 2025-03-28
AI Technical Summary
In the existing method for preparing anti-reverse gas diffusion layer, the coating is uneven, the aggregation and dispersion are poor, and the water gas transmission is affected after the resin is introduced, resulting in a decrease in the catalytic efficiency of the anti-reverse catalyst.
The anti-reverse catalyst is evenly distributed on the surface of the gas diffusion layer by electrophoresis, and no binder is used throughout the preparation process to avoid hindering the water and gas transmission.
The catalytic efficiency of the anti-reverse catalyst is effectively improved, ensuring that the water and gas transmission on the surface of the catalyst is not hindered, and the performance of the gas diffusion layer is improved.
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Abstract
Description
Technical Field
[0001] The present application relates to the technical field of fuel cells, and in particular to a preparation method of an anti-reverse polarity gas diffusion layer and an anti-reverse polarity gas diffusion layer. Background Art
[0002] Proton exchange membrane fuel cell is an electrochemical conversion device that uses hydrogen as energy to generate current. It has been recognized as the world's ultimate energy source because of its high energy conversion efficiency, excellent low-temperature performance and green environmental protection. The membrane electrode is the core component of the proton exchange membrane fuel cell. The membrane electrode is usually composed of three main parts: proton exchange membrane, catalyst layer and gas diffusion layer. Its performance and durability directly affect the use of the entire battery.
[0003] The main functions of the gas diffusion layer are, on the one hand, to transfer the anode and cathode reaction gases to the catalytic layer, and on the other hand, to discharge the product water, extract the reaction heat and transfer electrons. As an important place for water gas transmission, the gas diffusion layer is one of the main factors affecting the performance and durability of proton exchange membrane fuel cells.
[0004] However, automotive proton exchange membrane fuel cells will experience complex operating conditions such as start-stop, idling, high-power operation, and frequent load changes during use. Under these conditions, the anode will experience local hydrogen deficiency. However, in order to maintain the power required by the vehicle, the potential in this area will rise sharply and reverse polarity will occur, leading to water electrolysis and carbon corrosion. The occurrence of carbon corrosion will cause irreversible damage to the structure of the anode catalyst layer, and the nano-metal particles on the carbon carrier will undergo Ostwald ripening effect, causing the performance of the proton exchange membrane fuel cell to decay until failure. In addition, the local heat generated will cause pinholes to form on the proton exchange membrane, and these pinholes will cause serious consequences for the proton exchange membrane fuel cell.
[0005] Therefore, in order to avoid the adverse consequences of carbon corrosion, accelerating the electrolytic oxidation reaction (OER) of water has become the best route for anti-reversal. Generally, the anti-reversal gas diffusion layer is prepared by preparing the anti-reversal catalyst, resin solution and solvent into a slurry and coating it on the gas diffusion layer. This method is prone to uneven coating, aggregation and poor dispersion during the coating and drying process. In addition, the introduction of resin will affect the water vapor transmission, that is, the reactant water cannot reach the surface of the anti-reversal catalyst, and the product gas cannot be discharged in time, which greatly reduces the catalytic efficiency of the anti-reversal catalyst. Summary of the invention
[0006] The present application provides a method for preparing an anti-reversal gas diffusion layer and an anti-reversal gas diffusion layer, wherein an anti-reversal catalyst is evenly distributed on the surface of the gas diffusion layer by an electrophoresis method, and no adhesive is used in the entire preparation process to avoid hindering the water vapor transmission on the surface of the anti-reversal catalyst, thereby effectively improving the catalytic efficiency of the anti-reversal catalyst.
[0007] In one aspect, the present application provides a method for preparing an anti-reversal gas diffusion layer, the method comprising:
[0008] Heat-treating the nitrogen-carbon source to obtain a nitrogen-carbon carrier;
[0009] The nitrogen-carbon carrier, the noble metal precursor and the first solvent are mixed in a mass ratio of 1:(0.15-1):(5-100) to obtain a nitrogen-carbon carrier composite loaded with noble metal oxides;
[0010] The nitrogen-carbon carrier complex is uniformly dispersed in a second solvent to obtain an electrophoresis solution; the content of the nitrogen-carbon carrier complex in the electrophoresis solution is 0.1-10 wt %;
[0011] The clean gas diffusion layer is immersed in the electrophoresis solution for electrophoresis treatment, so that the nitrogen-carbon carrier complex is evenly distributed on the surface of the clean gas diffusion layer to obtain the anti-reverse polarity gas diffusion layer; the electrophoresis voltage of the electrophoresis treatment is 100-200V, and the electrophoresis time is 1-60min.
[0012] Furthermore, the clean gas diffusion layer is immersed in the electrophoresis solution for electrophoresis treatment, so that the nitrogen-carbon carrier composite is evenly distributed on the surface of the clean gas diffusion layer to obtain the anti-reverse polarity gas diffusion layer, comprising:
[0013] obtaining an initial gas diffusion layer;
[0014] Using an acetone solution to clean the initial gas diffusion layer to obtain the clean gas diffusion layer;
[0015] The clean gas diffusion layer and the clean platinum mesh are immersed in the electrophoresis solution, and the electrophoresis treatment is performed with the clean gas diffusion layer as the cathode and the clean platinum mesh as the anode, so that the nitrogen-carbon carrier complex is evenly distributed on the surface of the clean gas diffusion layer to obtain the anti-reverse polarity gas diffusion layer; the electrophoresis voltage is negatively correlated with the electrophoresis time.
[0016] Furthermore, the step of uniformly dispersing the nitrogen-carbon carrier composite into a second solvent to obtain an electrophoresis solution comprises:
[0017] Adding the nitrogen-carbon carrier complex to the second solvent to obtain an initial electrophoresis solution; the second solvent is one or more of water, ethanol, and isopropanol;
[0018] Magnesium nitrate is added to the initial electrophoresis solution, and the electrophoresis solution is obtained after uniform mixing; in the electrophoresis solution, the content of magnesium nitrate is 0.1-20wt%.
[0019] Furthermore, the nitrogen-carbon carrier, the noble metal precursor and the first solvent are mixed in a mass ratio of 1:(0.15-1):(5-100) to obtain a nitrogen-carbon carrier composite loaded with noble metal oxides, comprising:
[0020] The nitrogen-carbon carrier, the noble metal precursor and the first solvent are mixed in a mass ratio of 1:(0.15-1):(5-100) to obtain an initial mixture after mixing evenly; the first solvent is one or more of ultrapure water and ethanol;
[0021] Heat treating the initial mixture at 200-700° C. for 1-7 hours to obtain a heat-treated product;
[0022] The heat-treated product is ground to obtain the nitrogen-carbon carrier composite loaded with the noble metal oxide.
[0023] Furthermore, the heating treatment of the nitrogen-carbon source to obtain the nitrogen-carbon carrier comprises:
[0024] Heating the nitrogen-carbon source at 200-800° C. for 1-8 hours to obtain an initial nitrogen-carbon carrier;
[0025] The initial nitrogen-carbon carrier is ground to obtain the nitrogen-carbon carrier.
[0026] Furthermore, the atmosphere of the heat treatment is one or more of nitrogen, argon and hydrogen.
[0027] Furthermore, a plurality of noble metal oxide particles are evenly distributed on the surface of the nitrogen-carbon carrier composite, and the particle size of the noble metal oxide particles is 1-7 nm.
[0028] Furthermore, the noble metal precursor is one or more of chloroiridic acid, sodium chloroiridate, iridium chloride, potassium chloroiridate, iridium acetylacetonate, ammonium chloroiridate, potassium chloroiridate, ammonium chloroiridate, ruthenium chloride, ammonium chlororuthenate, ruthenium acetylacetonate, ruthenium nitrosyl nitrate, and potassium chlororuthenate.
[0029] Furthermore, the nitrogen and carbon sources are one or more of thiourea, urea, melamine and dicyandiamide.
[0030] On the other hand, an anti-reversing gas diffusion layer is provided. The anti-reversing gas diffusion layer is prepared by the above-mentioned preparation method. A nitrogen-carbon carrier composite is evenly distributed on the surface of the anti-reversing gas diffusion layer. The particle size of the nitrogen-carbon carrier composite is 50-500 μm.
[0031] The present application provides the following technical effects:
[0032] The present application heats a nitrogen-carbon source to obtain a nitrogen-carbon carrier; the nitrogen-carbon carrier, a noble metal precursor and a first solvent are mixed in a mass ratio of 1: (0.15-1): (5-100) to obtain a nitrogen-carbon carrier composite loaded with a noble metal oxide; the nitrogen-carbon carrier composite is uniformly dispersed in a second solvent to obtain an electrophoresis solution; in the electrophoresis solution, the content of the nitrogen-carbon carrier composite is 0.1-10wt%; a clean gas diffusion layer is immersed in the electrophoresis solution for electrophoresis treatment, so that the nitrogen-carbon carrier composite is uniformly distributed on the surface of the clean gas diffusion layer to obtain an anti-reverse polarity gas diffusion layer; the electrophoresis voltage of the electrophoresis treatment is 100-200V, and the electrophoresis time is 1-60min. The present application uses an electrophoresis method to uniformly distribute the anti-reverse polarity catalyst on the surface of the gas diffusion layer. No binder is used in the entire preparation process to avoid hindering the water vapor transmission on the surface of the anti-reverse polarity catalyst, which can effectively improve the catalytic efficiency of the anti-reverse polarity catalyst.
[0033] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS
[0034] In order to more clearly illustrate the technical solutions and advantages of the embodiments of this specification or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0035] Figure 1 It is a schematic flow chart of a method for preparing an anti-reverse polarity gas diffusion layer provided in an embodiment of this specification;
[0036] Figure 2 It is a schematic diagram of a process for preparing a nitrogen-carbon carrier provided in the examples of this specification;
[0037] Figure 3 It is a schematic diagram of a process for preparing a nitrogen-carbon carrier composite provided in an embodiment of this specification;
[0038] Figure 4 is a scanning electron microscope image of a nitrogen-carbon carrier composite provided in the examples of this specification;
[0039] Figure 5 It is a schematic diagram of a process for preparing an electrophoresis fluid provided in an embodiment of this specification;
[0040] Figure 6 It is a schematic diagram of a process of electrophoresis treatment provided in an embodiment of this specification;
[0041] Figure 7This is a scanning electron microscope image of an anti-reversal gas diffusion layer provided in an embodiment of this specification;
[0042] Figure 8 This is a performance comparison chart of an anti-reverse polarity gas diffusion layer provided in an embodiment of this specification and an original sample. DETAILED DESCRIPTION
[0043] The following will be combined with the drawings in the embodiments of this specification to clearly and completely describe the technical solutions in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.
[0044] The following describes a method for preparing an anti-reverse polarity gas diffusion layer of the present application, specifically as follows: Figure 1 As shown, the method may include:
[0045] S1: Heat the nitrogen-carbon source to obtain a nitrogen-carbon carrier.
[0046] Furthermore, if Figure 2 As shown, the heating treatment of the nitrogen-carbon source to obtain the nitrogen-carbon carrier may include:
[0047] S11: heating the nitrogen-carbon source at 200-800° C. for 1-8 hours to obtain an initial nitrogen-carbon carrier;
[0048] S12: Grinding the initial nitrogen-carbon carrier to obtain the nitrogen-carbon carrier.
[0049] In an embodiment of the present application, a nitrogen-carbon source is heated to obtain an initial nitrogen-carbon carrier, and then the initial nitrogen-carbon carrier is ground to obtain a nitrogen-carbon carrier. The heating temperature can be 200-800°C, and the heating time can be 1-8h, wherein the heating temperature is preferably 550°C, and the heating time is preferably 2h.
[0050] The embodiment of the present application obtains a nitrogen-carbon carrier by heating and grinding a nitrogen-carbon source, so that the anti-reversal catalyst is loaded on the nitrogen-carbon carrier, which can further increase the dispersibility of the active anti-reversal catalyst and inhibit the migration and agglomeration of the anti-reversal catalyst; and the carbon-nitrogen carrier will have a similar catalytic effect in decomposing water, which can further enhance the anti-reversal ability of the anti-reversal gas diffusion layer.
[0051] Furthermore, the nitrogen and carbon sources are one or more of thiourea, urea, melamine and dicyandiamide.
[0052] In an embodiment of the present application, a nitrogen-carbon source is used as a raw material for preparing a nitrogen-carbon carrier. The nitrogen-carbon source may be one or more of thiourea, urea, melamine, and dicyandiamide. The nitrogen-carbon carrier is obtained by heating and grinding the nitrogen-carbon source.
[0053] The embodiments of the present application select a suitable nitrogen-carbon source to obtain a nitrogen-carbon carrier, so that the anti-reversal catalyst can be loaded on the nitrogen-carbon carrier, thereby increasing the dispersibility of the anti-reversal catalyst and effectively inhibiting the migration and agglomeration of the anti-reversal catalyst.
[0054] S2: mixing the nitrogen-carbon carrier, the noble metal precursor and the first solvent in a mass ratio of 1:(0.15-1):(5-100) to obtain a nitrogen-carbon carrier composite loaded with noble metal oxides.
[0055] Furthermore, if Figure 3 As shown, the nitrogen-carbon carrier, the noble metal precursor and the first solvent are mixed in a mass ratio of 1: (0.15-1): (5-100) to obtain a nitrogen-carbon carrier composite loaded with noble metal oxides, which may include:
[0056] S21: mixing the nitrogen-carbon carrier, the noble metal precursor and the first solvent in a mass ratio of 1:(0.15-1):(5-100) to obtain an initial mixture after mixing evenly; the first solvent is one or more of ultrapure water and ethanol;
[0057] S22: heat-treating the initial mixture at 200-700° C. for 1-7 hours to obtain a heat-treated product;
[0058] S23: Grinding the heat-treated product to obtain the nitrogen-carbon carrier composite loaded with noble metal oxides.
[0059] In an embodiment of the present application, a nitrogen-carbon carrier, a noble metal precursor and a first solvent are mixed in a mass ratio of 1: (0.15-1): (5-100), the mixture obtained after uniform mixing is heat-treated, and the heat-treated product is ground to finally obtain a nitrogen-carbon carrier composite loaded with noble metal oxides, i.e., an anti-reverse polarity catalyst. The first solvent is one or more of ultrapure water and ethanol; the heat treatment temperature can be 200-700°C, and the heat treatment time can be 1-7h.
[0060] The embodiment of the present application mixes, heat treats and grinds the nitrogen-carbon carrier, the noble metal precursor and the first solvent, so that the noble metal oxide can be loaded on the surface of the nitrogen-carbon carrier to obtain an anti-reverse polarity catalyst, which can enhance the anti-reverse polarity of the anti-reverse polarity gas diffusion layer.
[0061] Furthermore, the atmosphere of the heat treatment is one or more of nitrogen, argon and hydrogen.
[0062] In an embodiment of the present application, when the initial mixture is heat-treated, the initial mixture needs to be placed in a specific gas atmosphere, wherein the heat treatment atmosphere can be one or more of nitrogen, argon, and hydrogen, so that the initial mixture can be heat-treated in a safe atmosphere, avoiding oxidation or other unwanted chemical reactions, and improving the quality and efficiency of the entire heat treatment process.
[0063] The embodiment of the present application can effectively prevent oxidation and other phenomena by performing the heat treatment process in a specific gas atmosphere, thereby ensuring the quality and efficiency of the heat treatment process.
[0064] Furthermore, the noble metal precursor is one or more of chloroiridic acid, sodium chloroiridate, iridium chloride, potassium chloroiridate, iridium acetylacetonate, ammonium chloroiridate, potassium chloroiridate, ammonium chloroiridate, ruthenium chloride, ammonium chlororuthenate, ruthenium acetylacetonate, ruthenium nitrosyl nitrate, and potassium chlororuthenate.
[0065] In the embodiments of the present application, a high-performance catalyst can be prepared by using a noble metal precursor, and the noble metal precursor, the nitrogen-carbon carrier and a suitable solvent are mixed, heat treated and ground to prepare an anti-reverse polarity catalyst with better catalytic performance, thereby enhancing the anti-reverse polarity of the anti-reverse polarity gas diffusion layer. Among them, the noble metal precursor can be one or more of chloroiridic acid, sodium chloroiridate, iridium chloride, potassium chloroiridate, iridium acetylacetonate, ammonium chloroiridate, potassium chloroiridate, ammonium chloroiridate, ruthenium chloride, ammonium chlororuthenate, ruthenium acetylacetonate, ruthenium nitrosyl nitrate, and potassium chlororuthenate. The specific usage can be selected and adjusted according to actual needs.
[0066] The embodiment of the present application uses a noble metal precursor as one of the raw materials for preparing an anti-reversal catalyst, which can effectively improve the catalytic performance of the anti-reversal catalyst.
[0067] Furthermore, a plurality of noble metal oxide particles are evenly distributed on the surface of the nitrogen-carbon carrier composite, and the particle size of the noble metal oxide particles is 1-7 nm.
[0068] In the examples of the present application, the scanning electron microscope image of the nitrogen-carbon carrier composite ( Figure 4 ) It can be seen that a plurality of precious metal oxide particles are evenly distributed on the surface of the nitrogen-carbon carrier composite, wherein the particle size of the precious metal oxide particles is 1-7 nm.
[0069] The examples of the present application show that the precious metal oxide particles can be evenly distributed on the surface of the nitrogen-carbon carrier, which can increase the dispersibility of the anti-reversal catalyst, inhibit the migration and agglomeration of the anti-reversal catalyst, and effectively ensure the catalytic effect of the anti-reversal catalyst.
[0070] S3: uniformly dispersing the nitrogen-carbon carrier complex in a second solvent to obtain an electrophoretic solution; in the electrophoretic solution, the content of the nitrogen-carbon carrier complex is 0.1-10 wt %.
[0071] Furthermore, if Figure 5 As shown, the step of uniformly dispersing the nitrogen-carbon carrier complex into a second solvent to obtain an electrophoretic solution may include:
[0072] S31: adding the nitrogen-carbon carrier complex to the second solvent to obtain an initial electrophoresis solution; the second solvent is one or more of water, ethanol, and isopropanol;
[0073] S32: adding magnesium nitrate to the initial electrophoresis solution, and mixing them evenly to obtain the electrophoresis solution; the content of magnesium nitrate in the electrophoresis solution is 0.1-20wt%.
[0074] In the embodiment of the present application, the nitrogen-carbon carrier complex is evenly dispersed in the second solvent, and magnesium nitrate is added and mixed to obtain an electrophoresis liquid. The second solvent may be one or more of water, ethanol, and isopropanol; in the electrophoresis liquid, the content of the nitrogen-carbon carrier complex may be 0.1-10wt%, and the content of magnesium nitrate may be 0.1-20wt%.
[0075] In the embodiments of the present application, the uniform dispersion method can be one or more of stirring, ultrasound, cell disruption, and homogenization. The dispersion time can be 1-5 hours, and the dispersion time is preferably 3 hours.
[0076] In the embodiment of the present application, the nitrogen-carbon carrier complex is prepared as an electrophoretic liquid so that the nitrogen-carbon carrier complex can be evenly distributed on the surface of the gas diffusion layer, thereby preparing an anti-reverse polarity gas diffusion layer by an electrophoretic method, so as to avoid the binder introduced in the traditional coating preparation method hindering the water vapor transmission on the surface of the anti-reverse polarity catalyst.
[0077] S4: immersing the clean gas diffusion layer into the electrophoresis solution for electrophoresis treatment, so that the nitrogen-carbon carrier complex is evenly distributed on the surface of the clean gas diffusion layer to obtain the anti-reverse polarity gas diffusion layer; the electrophoresis voltage of the electrophoresis treatment is 100-200V, and the electrophoresis time is 1-60min.
[0078] Furthermore, if Figure 6 As shown, the step of immersing the clean gas diffusion layer into the electrophoresis solution for electrophoresis treatment so that the nitrogen-carbon carrier composite is evenly distributed on the surface of the clean gas diffusion layer to obtain the anti-reverse polarity gas diffusion layer may include:
[0079] S41: obtaining an initial gas diffusion layer;
[0080] S42: using an acetone solution to clean the initial gas diffusion layer to obtain the clean gas diffusion layer;
[0081] S43: immersing the clean gas diffusion layer and the clean platinum mesh into the electrophoresis solution, and performing the electrophoresis treatment with the clean gas diffusion layer as the cathode and the clean platinum mesh as the anode, so that the nitrogen-carbon carrier complex is evenly distributed on the surface of the clean gas diffusion layer to obtain the anti-reverse polarity gas diffusion layer; the electrophoresis voltage is negatively correlated with the electrophoresis time.
[0082] In the embodiment of the present application, the initial gas diffusion layer is cleaned with a flowing acetone solution to obtain a clean gas diffusion layer, the clean gas diffusion layer and the clean platinum mesh are immersed in an electrophoresis solution, and the clean gas diffusion layer is used as a cathode and the clean platinum mesh is used as an anode for electrophoresis treatment, so that the nitrogen-carbon carrier complex is evenly distributed on the surface of the clean gas diffusion layer to obtain the final anti-reverse polarity gas diffusion layer. The electrophoresis voltage of the electrophoresis treatment can be 100-200V, and the electrophoresis time can be 1-60min.
[0083] In the embodiment of the present application, the electrophoresis voltage and the electrophoresis time during the electrophoresis treatment are negatively correlated. The corresponding electrophoresis voltage and electrophoresis time can be set according to needs. When the electrophoresis voltage is 100-150V, the electrophoresis time can be 40-60min; when the electrophoresis voltage is 150-180V, the electrophoresis time can be 10-40min; when the electrophoresis voltage is 180-200V, the electrophoresis time can be 1-10min.
[0084] In the embodiment of the present application, the electrophoresis treatment may not be limited to one electrophoresis treatment, but may be performed two or more times, so that the anti-reversal catalyst can be evenly distributed and in-situ grown on the surface of the gas diffusion layer. For example, immersing the clean gas diffusion layer in the electrophoresis solution, performing an electrophoresis treatment at 100-200V for 1-60min, to obtain an initial anti-reversal gas diffusion layer; performing a secondary electrophoresis treatment at 100-200V for 1-60min on the initial anti-reversal gas diffusion layer, to obtain an anti-reversal gas diffusion layer.
[0085] Furthermore, the above method may include:
[0086] Immersing the clean gas diffusion layer in electrophoresis solution, and performing an electrophoresis treatment at 100-150V for 20 minutes to obtain an initial anti-reverse polarity gas diffusion layer;
[0087] The initial anti-reversing gas diffusion layer is subjected to a secondary electrophoresis treatment for 20 minutes at 100-150 V to obtain the anti-reversing gas diffusion layer.
[0088] Furthermore, the above method may also include:
[0089] Immersing the clean gas diffusion layer in electrophoresis solution, and performing an electrophoresis treatment at 100-150V for 20 minutes to obtain an initial anti-reverse polarity gas diffusion layer;
[0090] The initial anti-reversing gas diffusion layer is subjected to a secondary electrophoresis treatment at 150-180 V for 10 min to obtain the anti-reversing gas diffusion layer.
[0091] In the embodiment of the present application, the voltage and time of multiple electrophoresis treatments may be different and may be adjusted according to the actual electrophoresis results so that the anti-reverse polarity catalyst can be evenly distributed and grown in situ on the surface of the gas diffusion layer.
[0092] The embodiment of the present application can evenly distribute the anti-reverse pole catalyst and grow it in situ on the surface of the gas diffusion layer at room temperature through the electrophoresis method. Compared with the traditional coating technology, there is no need to use any adhesive, including resin solution, etc., to avoid hindering the water vapor transmission on the surface of the anti-reverse pole catalyst, thereby effectively improving the catalytic efficiency of the anti-reverse pole catalyst.
[0093] The embodiment of the present application heats and grinds the nitrogen-carbon source to obtain a nitrogen-carbon carrier, and then mixes the nitrogen-carbon carrier, the noble metal precursor and the appropriate solvent, and then heat treats and grinds the mixture to obtain a nitrogen-carbon carrier composite loaded with noble metal oxides, and prepares the nitrogen-carbon carrier composite as an electrophoretic liquid, and uniformly distributes the nitrogen-carbon carrier composite to the clean gas diffusion layer surface by electrophoresis, and finally obtains an anti-reverse polar gas diffusion layer. The present application introduces a nitrogen-carbon carrier to load an anti-reverse polar catalyst, which can increase the dispersibility of the anti-reverse polar catalyst and inhibit the migration and agglomeration of the anti-reverse polar catalyst; and the carbon-nitrogen carrier also has a certain catalytic effect in decomposing water, which can further enhance the anti-reverse polarity of the anti-reverse polar gas diffusion layer; the anti-reverse polar catalyst can be uniformly distributed and grown in situ on the surface of the gas diffusion layer at room temperature by the electrophoretic method, compared with the traditional coating method, no binder needs to be added, including resin solution, etc., to avoid hindering the water vapor transmission on the surface of the anti-reverse polar catalyst, and the catalytic efficiency of the anti-reverse polar catalyst can be effectively improved.
[0094] The embodiment of the present application also provides an anti-reversing gas diffusion layer, which is prepared by the above-mentioned preparation method. A nitrogen-carbon carrier composite is evenly distributed on the surface of the anti-reversing gas diffusion layer, and the particle size of the nitrogen-carbon carrier composite is 50-500 μm.
[0095] In an embodiment of the present application, the anti-reversal gas diffusion layer comprises a gas diffusion layer composed of a carbon paper substrate and a microporous layer and a nitrogen-carbon anti-reversal catalyst loaded with precious metal oxides, wherein the precious metal oxides are nanoparticles loaded on a nitrogen-carbon carrier.
[0096] In the embodiment of the present application, the anti-reversal gas diffusion layer can be prepared by adopting the above-mentioned preparation method. The SEM image of the anti-reversal gas diffusion layer is as follows: Figure 7 As shown in the figure, it can be seen that the nitrogen-carbon carrier complex is evenly distributed on the surface of the anti-reverse pole gas diffusion layer, and the particle size of the nitrogen-carbon carrier complex is 50-500μm, indicating that the electrophoresis method can effectively make the anti-reverse pole catalyst evenly distributed and in-situ grown on the surface of the gas diffusion layer, thereby avoiding the traditional coating method that hinders the water vapor transmission on the surface of the anti-reverse pole catalyst due to the use of a binder, and can effectively improve the catalytic efficiency of the anti-reverse pole catalyst.
[0097] Embodiment 1:
[0098] This embodiment provides an anti-reverse polarity gas diffusion layer and a preparation method thereof. The specific preparation method includes:
[0099] Thiourea was heated at 550 °C for 2 h to obtain a nitrogen-carbon carrier;
[0100] The nitrogen-carbon carrier, iridium chloride and ultrapure water are mixed to obtain a nitrogen-carbon carrier composite loaded with noble metal oxides;
[0101] uniformly dispersing the nitrogen-carbon carrier complex in ethanol to obtain an electrophoresis solution;
[0102] The clean gas diffusion layer is immersed in an electrophoresis solution for electrophoresis treatment, so that the nitrogen-carbon carrier complex is evenly distributed on the surface of the clean gas diffusion layer to obtain an anti-reverse polarity gas diffusion layer; wherein the electrophoresis voltage of the electrophoresis treatment is 150V and the electrophoresis time is 40min.
[0103] Embodiment 2:
[0104] This embodiment provides an anti-reverse polarity gas diffusion layer and a preparation method thereof. The specific preparation method includes:
[0105] Thiourea was heated at 800 °C for 1 h to obtain a nitrogen-carbon carrier;
[0106] The nitrogen-carbon carrier, iridium chloride and ultrapure water are mixed to obtain a nitrogen-carbon carrier composite loaded with noble metal oxides;
[0107] uniformly dispersing the nitrogen-carbon carrier complex in ethanol to obtain an electrophoresis solution;
[0108] The clean gas diffusion layer is immersed in an electrophoresis solution for electrophoresis treatment, so that the nitrogen-carbon carrier complex is evenly distributed on the surface of the clean gas diffusion layer to obtain an anti-reverse polarity gas diffusion layer; wherein the electrophoresis voltage of the electrophoresis treatment is 200V and the electrophoresis time is 1 minute.
[0109] Embodiment 3:
[0110] This embodiment provides an anti-reverse polarity gas diffusion layer and a preparation method thereof. The specific preparation method includes:
[0111] Thiourea was heated at 200 °C for 8 h to obtain a nitrogen-carbon carrier;
[0112] The nitrogen-carbon carrier, iridium chloride and ultrapure water are mixed to obtain a nitrogen-carbon carrier composite loaded with noble metal oxides;
[0113] uniformly dispersing the nitrogen-carbon carrier complex in ethanol to obtain an electrophoresis solution;
[0114] The clean gas diffusion layer is immersed in an electrophoresis solution for electrophoresis treatment, so that the nitrogen-carbon carrier complex is evenly distributed on the surface of the clean gas diffusion layer to obtain an anti-reverse polarity gas diffusion layer; wherein the electrophoresis voltage of the electrophoresis treatment is 100V and the electrophoresis time is 60min.
[0115] Embodiment 4:
[0116] This embodiment provides an anti-reverse polarity gas diffusion layer and a preparation method thereof. The specific preparation method includes:
[0117] Thiourea was heated at 500 °C for 2 h to obtain a nitrogen-carbon carrier;
[0118] The nitrogen-carbon carrier, iridium chloride and ultrapure water are mixed to obtain a nitrogen-carbon carrier composite loaded with noble metal oxides;
[0119] uniformly dispersing the nitrogen-carbon carrier complex in ethanol to obtain an electrophoresis solution;
[0120] The clean gas diffusion layer is immersed in an electrophoresis solution for electrophoresis treatment, so that the nitrogen-carbon carrier complex is evenly distributed on the surface of the clean gas diffusion layer to obtain an anti-reverse polarity gas diffusion layer; wherein the electrophoresis voltage of the electrophoresis treatment is 160V and the electrophoresis time is 15min.
[0121] In the examples of the present application, a gas diffusion layer without an anti-reverse polarity catalyst was prepared by a conventional coating method as an original sample, and compared with the anti-reverse polarity gas diffusion layer prepared in the present application, and a performance test was performed. The test results are shown in FIG. Figure 8 As the conventional coating method for preparing the gas diffusion layer can be found in various materials, it will not be described in detail in this application.
[0122] In the embodiments of the present application, Figure 8 Current Density refers to current density, Cell Voltage refers to battery voltage and slot voltage, and HFR (High Frequency Resistance) refers to high frequency resistance. Figure 8 As shown, by comparing the polarization curve and high-frequency resistance of the anti-reversing gas diffusion layer with those of the original sample, it can be found that the performance of the anti-reversing gas diffusion layer prepared by the preparation method of the anti-reversing gas diffusion layer provided in the embodiment of the present application is significantly better than the performance of the gas diffusion layer prepared by the traditional coating method, which shows that the preparation method of the anti-reversing gas diffusion layer provided in the embodiment of the present application can effectively improve the catalytic efficiency of the catalyst.
[0123] It can be seen from the embodiments provided by the present application that the present application heats the nitrogen-carbon source to obtain a nitrogen-carbon carrier; the nitrogen-carbon carrier, the noble metal precursor and the first solvent are mixed in a mass ratio of 1:(0.15-1):(5-100) to obtain a nitrogen-carbon carrier composite loaded with a noble metal oxide; the nitrogen-carbon carrier composite is uniformly dispersed in a second solvent to obtain an electrophoresis liquid; in the electrophoresis liquid, the content of the nitrogen-carbon carrier composite is 0.1-10wt%; the clean gas diffusion layer is immersed in the electrophoresis liquid for electrophoresis treatment, so that the nitrogen-carbon carrier composite is uniformly distributed on the surface of the clean gas diffusion layer to obtain an anti-reverse polarity gas diffusion layer; the electrophoresis voltage of the electrophoresis treatment is 100-200V, and the electrophoresis time is 1-60min. The present application introduces a nitrogen-carbon carrier to load the anti-reversal catalyst, which can increase the dispersibility of the anti-reversal catalyst and inhibit the migration and agglomeration of the anti-reversal catalyst; and the carbon-nitrogen carrier also has a certain catalytic effect in decomposing water, which can further enhance the anti-reversal ability of the anti-reversal gas diffusion layer; the anti-reversal catalyst can be evenly distributed and grown in situ on the surface of the gas diffusion layer at room temperature by the electrophoresis method. Compared with the traditional coating method, there is no need to add any binder, including resin solution, etc., to avoid hindering the water vapor transmission on the surface of the anti-reversal catalyst, which can effectively improve the catalytic efficiency of the anti-reversal catalyst.
[0124] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.
Claims
1. A method for preparing an anti-reversal gas diffusion layer, characterized in that: The method comprises: Heat-treating the nitrogen-carbon source to obtain a nitrogen-carbon carrier; The nitrogen-carbon carrier, the noble metal precursor and the first solvent are mixed in a mass ratio of 1:(0.15-1):(5-100) to obtain a nitrogen-carbon carrier composite loaded with noble metal oxides; The nitrogen-carbon carrier complex is uniformly dispersed in a second solvent to obtain an electrophoresis solution; the content of the nitrogen-carbon carrier complex in the electrophoresis solution is 0.1-10 wt %; The clean gas diffusion layer is immersed in the electrophoresis solution for electrophoresis treatment, so that the nitrogen-carbon carrier complex is evenly distributed on the surface of the clean gas diffusion layer to obtain the anti-reverse polarity gas diffusion layer; the electrophoresis voltage of the electrophoresis treatment is 100-200V, and the electrophoresis time is 1-60min.
2. The method according to claim 1, characterized in that The step of immersing the clean gas diffusion layer into the electrophoresis solution for electrophoresis treatment so that the nitrogen-carbon carrier composite is evenly distributed on the surface of the clean gas diffusion layer to obtain the anti-reverse polarity gas diffusion layer comprises: obtaining an initial gas diffusion layer; Using an acetone solution to clean the initial gas diffusion layer to obtain the clean gas diffusion layer; The clean gas diffusion layer and the clean platinum mesh are immersed in the electrophoresis solution, and the electrophoresis treatment is performed with the clean gas diffusion layer as the cathode and the clean platinum mesh as the anode, so that the nitrogen-carbon carrier complex is evenly distributed on the surface of the clean gas diffusion layer to obtain the anti-reverse polarity gas diffusion layer; the electrophoresis voltage is negatively correlated with the electrophoresis time.
3. The method according to claim 1, characterized in that: The step of uniformly dispersing the nitrogen-carbon carrier composite into a second solvent to obtain an electrophoresis solution comprises: Adding the nitrogen-carbon carrier complex to the second solvent to obtain an initial electrophoresis solution; the second solvent is one or more of water, ethanol, and isopropanol; Magnesium nitrate is added to the initial electrophoresis solution, and the electrophoresis solution is obtained after uniform mixing; in the electrophoresis solution, the content of magnesium nitrate is 0.1-20wt%.
4. The method according to claim 1, characterized in that: The nitrogen-carbon carrier, the noble metal precursor and the first solvent are mixed in a mass ratio of 1:(0.15-1):(5-100) to obtain a nitrogen-carbon carrier composite loaded with noble metal oxides, comprising: The nitrogen-carbon carrier, the noble metal precursor and the first solvent are mixed in a mass ratio of 1:(0.15-1):(5-100) to obtain an initial mixture after mixing evenly; the first solvent is one or more of ultrapure water and ethanol; Heat treating the initial mixture at 200-700° C. for 1-7 hours to obtain a heat-treated product; The heat-treated product is ground to obtain the nitrogen-carbon carrier composite loaded with the noble metal oxide.
5. The method according to claim 1, characterized in that The step of heating the nitrogen-carbon source to obtain the nitrogen-carbon carrier comprises: Heating the nitrogen-carbon source at 200-800° C. for 1-8 hours to obtain an initial nitrogen-carbon carrier; The initial nitrogen-carbon carrier is ground to obtain the nitrogen-carbon carrier.
6. The method according to claim 4, characterized in that The heat treatment atmosphere is one or more of nitrogen, argon and hydrogen.
7. The method according to claim 4, characterized in that A plurality of noble metal oxide particles are evenly distributed on the surface of the nitrogen-carbon carrier composite, and the particle size of the noble metal oxide particles is 1-7 nm.
8. The method according to claim 4, characterized in that The noble metal precursor is one or more of chloroiridic acid, sodium chloroiridate, iridium chloride, potassium chloroiridate, iridium acetylacetonate, ammonium chloroiridate, potassium chloroiridate, ammonium chloroiridate, ruthenium chloride, ammonium chlororuthenate, ruthenium acetylacetonate, ruthenium nitrosyl nitrate, and potassium chlororuthenate.
9. The method according to claim 5, characterized in that The nitrogen and carbon sources are one or more of thiourea, urea, melamine and dicyandiamide.
10. An anti-reversal gas diffusion layer, characterized in that: The anti-reversing gas diffusion layer is prepared by the preparation method according to any one of claims 1 to 9, a nitrogen-carbon carrier composite is evenly distributed on the surface of the anti-reversing gas diffusion layer, and the particle size of the nitrogen-carbon carrier composite is 50-500 μm.