Membrane electrode preparation method combining plasma etching with rotary hot-pressing transfer printing, membrane electrode and application of membrane electrode

Abstract

The invention relates to the technical field of fuel cells, in particular to a preparation method of a membrane electrode combining plasma etching and rotary hot-pressing transfer printing, the membrane electrode and application of the membrane electrode, and the preparation method comprises the following steps: carrying out plasma discharge etching treatment on a transfer printing substrate; a graphite plate, a protective layer, a first pretreatment transfer printing base material, a proton exchange membrane, a second pretreatment transfer printing base material, a protective layer and a graphite plate are sequentially stacked and flatly laid for rotary hot-pressing transfer printing treatment, and a hot-pressed membrane electrode is obtained; wherein the first pretreatment transfer printing base material is an etched transfer printing base material coated with an anode catalyst layer, and the second pretreatment transfer printing base material is an etched transfer printing base material coated with a cathode catalyst layer; and removing the first pretreatment transfer printing base material and the second pretreatment transfer printing base material on the hot-pressed membrane electrode, pasting carbon paper, sealing a frame, and carrying out punch forming to obtain the membrane electrode. Through the synergistic effect of plasma etching and rotary hot-pressing transfer printing, the prepared membrane electrode has relatively high peak power density.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and in particular to a membrane electrode preparation method combining plasma etching with rotary hot pressing transfer, a membrane electrode and applications thereof. Background Art

[0002] In recent decades, the massive consumption of fossil fuels has led to environmental pollution. Therefore, the development of clean and renewable energy has become a top priority in the short term. Hydrogen is an attractive alternative energy carrier due to its ultra-high energy density (140MJ kg -1 ) and carbon-free characteristics, it is one of the most promising renewable energy sources to alleviate excessive dependence on fossil fuels. Proton exchange membrane fuel cell (PEMFC) is a very clean and efficient power source that can directly convert the chemical energy of hydrogen fuel into electrical energy. The membrane electrode assembly (MEA) is the core of PEMFC. The common membrane electrode manufacturing methods currently include catalyst coated membrane (CCM) process and gas diffusion electrode (GDE) process. Among them, the CCM process is currently more widely used, and can be further divided into two different methods. One method is to apply the catalyst ink directly to the proton exchange membrane by spray deposition. The other is the well-known hot pressing transfer method, which involves forming a catalytic layer on a substrate and then transferring it to the proton exchange membrane by hot pressing.

[0003] At present, a large number of patents and articles focus on how to maximize the transfer rate to reduce the loss of catalysts during the preparation of MEA, because this is a key and challenging goal in the hot press transfer method. For example, Cho et al. used a novel liquid nitrogen freezing method to increase the transfer rate of the catalyst layer on the transfer medium from 95.4% to 99.2%, but there are problems such as cumbersome operation methods and unsuitable for large-area membrane electrode preparation; US Patent US5211984A discloses a process for preparing membrane electrodes using the transfer method, that is, the cathode and anode catalyst slurries are coated on two different transfer media, and then the two transfer media are placed on both sides of a proton exchange membrane, and then hot press transfer is performed to remove the transfer medium to obtain a three-in-one membrane electrode. However, the problem with this method is that the viscosity of the slurry is high, and the viscosity of the slurry needs to match the transfer medium, otherwise it will lead to uneven distribution of the initial catalytic layer, which seriously affects the performance and life of the membrane electrode. In addition, during hot pressing transfer, the catalyst layer of the proton exchange membrane and the transfer medium cannot be completely transferred to the membrane due to uneven force, which greatly reduces the yield rate of the membrane electrode. Chinese patent CN 112803029B discloses a method for preparing a membrane electrode using a transfer process, dispersing an antioxidant into the catalyst layer of the electrode and the ion exchange layer of the electrolyte membrane to improve the interfacial bonding force between the electrode and the electrolyte membrane, but excessive antioxidants make the ionomers not evenly distributed and the contact with the electrode is relatively reduced, which leads to a significant decrease in the performance of the membrane electrode. Summary of the invention

[0004] In view of this, the present invention proposes a membrane electrode preparation method, a membrane electrode and its application combining plasma etching and rotary hot pressing transfer to solve the technical problem of reduced membrane electrode performance caused by uneven catalyst loading or antioxidant distribution in existing membrane electrode preparation methods.

[0005] The technical solution of the present invention is implemented as follows: The present invention provides a method for preparing a membrane electrode by plasma etching combined with rotary hot pressing transfer, comprising the following steps:

[0006] S1, performing plasma discharge etching on the transfer substrate to obtain an etched transfer substrate;

[0007] S2, stacking and paving a graphite plate, a protective layer, a first pre-treated transfer substrate, a proton exchange membrane, a second pre-treated transfer substrate, a protective layer, and a graphite plate in sequence to form a transfer sample, and performing hot pressing transfer treatment by a rotary hot pressing transfer process to obtain a hot pressed membrane electrode; wherein the first pre-treated transfer substrate is an etched transfer substrate coated with an anode catalyst layer, and the second pre-treated transfer substrate is an etched transfer substrate coated with a cathode catalyst layer;

[0008] S3, removing the first pre-treated transfer substrate and the second pre-treated transfer substrate on the membrane electrode after hot pressing, and performing stamping to obtain a membrane electrode.

[0009] On the basis of the above technical solution, preferably, in step S1, the power of the plasma discharge etching process is 50-100 W, the discharge time is 30-150 s, and the gas is argon.

[0010] On the basis of the above technical scheme, preferably, in step S2, the rotary hot pressing transfer process specifically includes: after hot pressing the transfer sample, rotate 60-120° before the next hot pressing, each transfer sample rotates a total of 360°, the temperature of the hot pressing transfer is 130-160°C, the pressure is 1.0-3.0MPa, and the hot pressing transfer time is 30-90s.

[0011] In the present invention, plasma etching bombards the transfer substrate surface with high-energy particles, removes surface pollutants and introduces microscopic defects, and generates polar functional groups (such as hydroxyl or carbonyl) on the substrate surface, thereby improving the wettability and adhesion of the substrate, making the catalyst slurry coating more uniform, and providing a uniform catalyst layer foundation for subsequent hot pressing transfer; rotary hot pressing transfer further ensures the integrity and uniformity of the catalyst layer by multiple uniform forces. During the rotary hot pressing transfer process, the catalyst layer is uniformly stressed in different directions through multiple hot pressing and rotation operations, avoiding deformation or damage of the catalyst layer caused by concentrated pressure in a single direction. The setting of the rotation angle range (60-120°) flexibly adapts to the needs of different hot pressing times, ensuring uniformity and improving process efficiency. The pressure and time applied during the rotary hot pressing process are small (pressure is 1.0-3.0MPa, time is 30-90s), which effectively avoids excessive compaction or destruction of the pore structure of the catalyst layer, thereby maintaining the high activity and good gas diffusion performance of the catalyst layer.

[0012] On the basis of the above technical scheme, preferably, the cathode catalyst is coated on one side close to the proton exchange membrane, and the cathode catalyst is one or two of Pt / C, PtCo / C, and PtNi catalysts; the content of the precious metal in the cathode catalyst ranges from 10 to 70 wt%; the content of carbon in the cathode catalyst ranges from 30 to 90 wt%.

[0013] On the basis of the above technical solution, preferably, the anode catalyst is one or two of Pt / C and PtRu / C catalysts, the content of precious metal in the anode catalyst is in the range of 5-30wt%; the content of carbon in the anode catalyst is in the range of 70-95wt%.

[0014] On the basis of the above technical solution, preferably, the anode catalyst is coated on the side close to the proton exchange membrane, and the loading of the noble metal of the cathode catalyst layer is set to 0.2-2.0 mg / cm 2 The loading of the noble metal in the anode catalyst layer is set to 0.05-0.2 mg / cm 2 .

[0015] Precious metals are active centers of catalytic reactions. The precious metal content range of the present invention is limited so that the catalyst layer can ensure sufficient number of active sites and appropriately reduce the amount of platinum used, thereby achieving a balance between performance and cost. Carbon materials, as carriers of catalysts, have excellent electrical conductivity and specific surface area, and can provide more precious metal dispersion sites. The present invention further limits the carbon content to balance the precious metal loading, electrical conductivity and mechanical stability of the catalyst, wherein a carbon content of 30-50wt% is suitable for catalysts with higher platinum content, while a carbon content of 70-90wt% is more suitable for low platinum usage.

[0016] On the basis of the above technical solution, preferably, the protective layer is one of PI, PPS and PEN, and the area of ​​the protective layer is greater than or equal to the area of ​​the membrane electrode; the transfer substrate is PTFE film and / or glass fiber paper.

[0017] On the basis of the above technical solution, preferably, the thickness of the proton exchange membrane is 5 to 30 μm.

[0018] The present invention provides a membrane electrode, which is prepared by using any of the membrane electrode preparation methods described above.

[0019] The present invention provides the use of the membrane electrode as described above in a fuel cell stack.

[0020] On the basis of the above technical scheme, preferably, the application of the membrane electrode comprises: assembling the membrane electrode onto a single cell, using the reaction gas (H2 and O2) as the activation medium, performing activation treatment, during which the stack temperature is 65-75°C, the anode / cathode flow rates are 2 and 1 slpm respectively, the gas inlet pressure is 100 kPa, the relative humidity (RH) of the reaction gas is 100%, and the current density is 1000 mA cm -2 The activation time is 3.5-4.5h. After activation, the single cell is reduced to open circuit voltage.

[0021] The plasma etching combined with rotary hot pressing transfer membrane electrode preparation method, membrane electrode and application thereof of the present invention have the following beneficial effects compared with the prior art:

[0022] (1) By combining the two major technical means of plasma etching and rotary hot pressing transfer, the problems of uneven catalyst coating, incomplete transfer, and easy damage to the pore structure of the catalyst layer during the preparation of the membrane electrode are solved. Among them, plasma etching improves the wettability and adhesion of the transfer substrate surface, and improves the quality of the catalyst coating; rotary hot pressing transfer adopts multiple low-pressure short-time hot pressing and rotary uniform force to further ensure the integrity of the catalyst layer and the transfer efficiency, thereby preparing a membrane electrode with excellent performance and long service life. The test results show that the peak power density of the membrane electrode prepared by the technical solution of the present invention is increased by 21.74%, and the catalyst loss rate and process cost are significantly reduced. It is suitable for proton exchange membrane fuel cells and water electrolysis hydrogen production and other fields;

[0023] (2) By dividing the hot pressing transfer process into multiple times, each time rotating a certain angle, a total of 360 degrees, the catalyst layer is evenly stressed during the transfer process, and the transfer rate of the catalyst layer is 100%. In addition, due to the use of multiple hot pressing transfers, the pressure and time of each hot pressing transfer are relatively small, and the original pore structure of the catalyst layer will not be excessively damaged, so that the membrane electrode prepared by this method has a higher peak power density. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 It is a schematic structural diagram of the transfer sample of the present invention;

[0026] Figure 2 This is a product picture of the membrane electrode prepared in Example 1 of the present invention;

[0027] Figure 3 This is a product picture of the membrane electrode prepared in Comparative Example 1 of the present invention;

[0028] Figure 4 This is a product picture of the membrane electrode prepared in Comparative Example 2 of the present invention;

[0029] Figure 5 The distribution diagram of platinum loading of membrane electrodes prepared in Example 1 and Comparative Example 1 of the present invention;

[0030] Figure 6 The product pictures of membrane electrode packages prepared in Examples 1-3 and Comparative Examples 1 and 3 of the present invention;

[0031] Figure 7The performance test diagram of the membrane electrode prepared by Example 1 and Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0032] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Example 1

[0034] This embodiment provides a membrane electrode combined with plasma etching and rotary hot pressing transfer and a preparation method thereof, comprising the following steps:

[0035] (1) subjecting a PTFE transfer substrate to a plasma discharge etching treatment to obtain a PTFE transfer substrate having surface defects, wherein the power of the plasma discharge etching treatment is 80 W, the discharge time is 90 s, and the gas is argon;

[0036] (2) 70% Pt / C catalyst slurry was slit coated on a 100 μm thick etched transfer substrate to obtain PTFE coated with 70% Pt / C cathode catalyst layer; 25% Pt / C catalyst slurry was coated on a 100 μm thick etched transfer substrate to obtain PTFE coated with 25% Pt / C anode catalyst, and the platinum loadings of the anode catalyst layer and the cathode catalyst layer were 0.2 and 0.8 mg, respectively. Pt / cm 2 ;

[0037] (3) The graphite plate, protective film, PTFE coated with an anode catalyst layer, proton exchange membrane (12 μm), PTFE coated with a cathode catalyst layer, protective film, and graphite plate are stacked and laid flat in sequence to form a transfer sample (such as Figure 1 As shown), then put it on a flat hot press, set the hot press temperature to 130°C, the transfer pressure to 1.2MPa, the hot press transfer treatment time to 60 seconds, and perform 4 hot press transfers in total. After each hot press transfer, rotate the transferred sample 90° for the next hot press;

[0038] (4) Finally, membrane electrode is formed, the PTFE substrate on the membrane electrode transferred by flat plate hot pressing is removed, carbon paper is pasted, the frame is sealed, and the membrane electrode is obtained after stamping.

[0039] Example 2

[0040] This embodiment provides a membrane electrode combined with plasma etching and rotary hot pressing transfer and a preparation method thereof, comprising the following steps:

[0041] (1) subjecting a PTFE transfer substrate to a plasma discharge etching treatment to obtain a PTFE transfer substrate having surface defects, wherein the power of the plasma discharge etching treatment is 50 W, the discharge time is 150 s, and the gas is argon;

[0042] (2) 10% PtCo / C catalyst slurry was slit coated on a 100 μm thick etched transfer substrate to obtain PTFE coated with a 10% PtCo / C cathode catalyst layer; 5% PtRu / C catalyst slurry was coated on a 100 μm thick etched transfer substrate to obtain PTFE coated with a 5% PtRu / C anode catalyst, and the platinum loadings of the anode catalyst layer and the cathode catalyst layer were 0.05 and 0.2 mg, respectively. Pt / cm 2 ;

[0043] (3) The graphite plate, protective film, PTFE coated with an anode catalyst layer, proton exchange membrane (12 μm), PTFE coated with a cathode catalyst layer, protective film, and graphite plate are stacked and laid flat in sequence to form a transfer sample, which is then placed on a flat hot press machine. The hot press temperature is set to 145° C., the transfer pressure is set to 3.0 MPa, and the hot press transfer treatment time is 90 s. A total of 6 hot press transfers are performed. After each hot press transfer, the transfer sample is rotated 60 degrees for the next hot press;

[0044] (4) Finally, membrane electrode is formed, the PTFE substrate on the membrane electrode transferred by flat plate hot pressing is removed, carbon paper is pasted, the frame is sealed, and the membrane electrode is obtained after stamping.

[0045] Example 3

[0046] This embodiment provides a membrane electrode combined with plasma etching and rotary hot pressing transfer and a preparation method thereof, comprising the following steps:

[0047] (1) subjecting a PTFE transfer substrate to a plasma discharge etching treatment to obtain a PTFE transfer substrate having surface defects, wherein the power of the plasma discharge etching treatment is 100 W, the discharge time is 30 s, and the gas is argon;

[0048] (2) 40% Pt / C catalyst slurry was slit coated on a 100 μm thick etched transfer substrate to obtain PTFE coated with a 40% Pt / C cathode catalyst layer; 30% Pt / C catalyst slurry was coated on a 100 μm thick etched transfer substrate to obtain PTFE coated with a 30% Pt / C anode catalyst, and the platinum loadings of the anode catalyst layer and the cathode catalyst layer were 0.1 and 2.0 mg, respectively. Pt / cm 2 ;

[0049] (3) stacking the graphite plate, protective film, PTFE coated with an anode catalyst layer, proton exchange membrane (12 μm), PTFE coated with a cathode catalyst layer, protective film, and graphite plate in sequence to form a transfer sample, and then placing it on a flat hot press, setting the hot press temperature to 160°C, the transfer pressure to 1.0 MPa, and the hot press transfer treatment time to 30 s, performing a total of 3 hot press transfers, and rotating the transfer sample 120° after each hot press transfer for the next hot press;

[0050] (4) Finally, membrane electrode is formed, the PTFE substrate on the membrane electrode transferred by flat plate hot pressing is removed, carbon paper is pasted, the frame is sealed, and the membrane electrode is obtained after stamping.

[0051] Comparative Example 1

[0052] This comparative example provides a membrane electrode combined with plasma etching and rotary hot pressing transfer and a preparation method thereof, which is different from Example 1 in that no plasma etching treatment is performed, and comprises the following steps:

[0053] (1) 70% Pt / C catalyst slurry was slit coated on a transfer substrate with a thickness of 100 μm to obtain PTFE coated with a 70% Pt / C cathode catalyst layer; 25% Pt / C catalyst slurry was coated on a transfer substrate with a thickness of 100 μm to obtain PTFE coated with a 25% Pt / C anode catalyst, and the platinum loadings of the anode catalyst layer and the cathode catalyst layer were 0.2 and 0.8 mg, respectively. Pt / cm 2 ;

[0054] (2) stacking a graphite plate, a protective film, a PTFE coated with an anode catalyst layer, a proton exchange membrane (12 μm), a PTFE coated with a cathode catalyst layer, a protective film, and a graphite plate in sequence to form a transfer sample, which is then placed on a flat hot press, the hot press temperature is set to 130°C, the transfer pressure is set to 1.2 MPa, the hot press transfer treatment time is 60 seconds, and a total of 4 hot press transfers are performed. After each hot press transfer, the transfer sample is rotated 90° for the next hot press;

[0055] (3) Finally, membrane electrode is formed, the PTFE substrate on the membrane electrode transferred by flat plate hot pressing is removed, carbon paper is pasted, the frame is sealed, and the membrane electrode is obtained after stamping.

[0056] Comparative Example 2

[0057] This comparative example provides a membrane electrode combined with plasma etching and rotary hot pressing transfer and a preparation method thereof, which is different from Example 1 in that no rotary transfer hot pressing is provided, and comprises the following steps:

[0058] (1) subjecting a PTFE transfer substrate to a plasma discharge etching treatment to obtain a PTFE transfer substrate having surface defects, wherein the power of the plasma discharge etching treatment is 80 W, the discharge time is 90 s, and the gas is argon;

[0059] (2) 70% Pt / C catalyst slurry was slit coated on a 100 μm thick etched transfer substrate to obtain PTFE coated with 70% Pt / C cathode catalyst layer; 25% Pt / C catalyst slurry was coated on a 100 μm thick etched transfer substrate to obtain PTFE coated with 25% Pt / C anode catalyst, and the platinum loadings of the anode catalyst layer and the cathode catalyst layer were 0.2 and 0.8 mg, respectively. Pt / cm 2 ;

[0060] (3) stacking the graphite plate, protective film, PTFE coated with an anode catalyst layer, proton exchange membrane (12 μm), PTFE coated with a cathode catalyst layer, protective film, and graphite plate in sequence to form a transfer sample, and then placing it on a flat hot press machine, setting the hot press temperature to 130° C., the transfer pressure to 1.2 MPa, the hot press transfer treatment time to 60 s, and performing one hot press transfer;

[0061] (4) Finally, membrane electrode is formed, the PTFE substrate on the membrane electrode transferred by flat plate hot pressing is removed, carbon paper is pasted, the frame is sealed, and the membrane electrode is obtained after stamping.

[0062] Comparative Example 3

[0063] This comparative example provides a common GDE membrane electrode and a preparation method thereof, comprising the following steps:

[0064] (1) 70% Pt / C catalyst slurry was slit coated on carbon paper with a thickness of 100 μm to obtain carbon paper coated with 70% Pt / C cathode catalyst layer; 25% Pt / C catalyst slurry was coated on carbon paper with a thickness of 100 μm to obtain carbon paper coated with 25% Pt / C anode catalyst, and the platinum loadings of the anode catalyst layer and the cathode catalyst layer were 0.2 and 0.8 mg, respectively. Pt / cm 2 ;

[0065] (2) stacking a graphite plate, a protective film, a carbon paper coated with an anode catalyst layer, a proton exchange membrane (12 μm), a carbon paper coated with a cathode catalyst layer, a protective film, and a graphite plate in sequence to form a transfer sample, and then placing it on a flat hot press, setting the hot press temperature to 130° C., the transfer pressure to 1.2 MPa, the hot press transfer treatment time to 60 s, and performing a hot press transfer once;

[0066] (3) Finally, membrane electrode forming is performed, the carbon paper on the membrane electrode transferred by flat hot pressing is removed, carbon paper is pasted, the frame is sealed, and a common GDE membrane electrode is obtained after stamping.

[0067] Performance Testing

[0068] 1. Take the membrane electrode prepared in the embodiment and the comparative example, select 9 points of the membrane electrode, the spacing between each point is greater than or equal to 1 cm, use X-ray fluorescence spectrometer to test the platinum loading of the membrane electrode, and record it.

[0069] Figure 2 The product picture of the membrane electrode prepared in Example 1 is shown. Figure 3 The product picture of the membrane electrode prepared in Comparative Example 1 is shown. Figure 4 The product picture of the membrane electrode prepared in comparative example 2 is shown. As can be seen from the figure, the transfer rate of the catalyst layer of the membrane electrode prepared in Example 1 is 100%, while the catalyst layer of both comparative examples 1 and 2 cannot be completely transferred and the membrane electrode cannot be used. Therefore, the membrane electrode prepared by the technical solution of the present invention has better integrity.

[0070] Figure 5 The platinum loading distribution diagram of the membrane electrode prepared in Example 1 and Comparative Example 1 is shown. As can be seen from the figure, the extreme difference in platinum loading of the membrane electrode of Example 1 is 0.07 mg. Pt cm -2 , compared with the membrane electrode of comparative example 1 (extreme difference is 0.37mg Pt cm -2 ) is more uniform.

[0071] 2. Take the membrane electrode prepared in the embodiment and the comparative example, and test the performance of the membrane electrode under hydrogen and oxygen conditions. The active area of ​​the membrane electrode is 50cm 2The membrane electrode was assembled into a short stack of 5 sections for testing to characterize the performance of the membrane electrode in an actual fuel cell stack. The membrane electrode was assembled into a single cell fixture and installed on the fuel cell test platform. The reaction gas (H2 and O2) was used as the activation medium to activate the single cell according to the following operating conditions: the battery test temperature was 70°C, the back pressure on the anode and cathode sides was 100 kPa, the gas humidity was 100%, and the current density was 1000 mA cm -2 The activation time is 4 hours. After the activation is completed, the single cell is reduced to the open circuit voltage. Under the specified battery operating conditions, the peak power density of the membrane electrode is tested in a constant current mode. The test results are shown in Table 1.

[0072] Table 1 Membrane electrode performance

[0073]

[0074]

[0075] Figure 6 The product pictures of the membrane electrode assembly prepared in Example 1 and Comparative Example 3 are shown. Figure 7 The performance test diagram of the membrane electrode prepared in Examples 1-3 and Comparative Examples 1 and 3 applied to a low-temperature hydrogen-oxygen proton exchange membrane fuel cell is shown in Table 1 and Figure 7 It can be seen that the performance of the membrane electrode prepared by the present invention is improved by 21.74% compared with the membrane electrode prepared by the conventional process, indicating that the membrane electrode prepared by rotary hot pressing transfer has better performance; further, by comparing Example 1 with Comparative Examples 1, 2 and 3, it is shown that plasma etching combined with rotary hot pressing transfer can significantly improve the performance of the membrane electrode, among which the narrow coating catalytic layer in Comparative Example 1 has a poor effect, resulting in uneven distribution of platinum loading in the catalytic layer, thereby affecting the membrane electrode performance; in Comparative Example 2, the transfer rate of the catalytic layer cannot reach 100% after rotary transfer is not used, and thus the membrane electrode prepared by the catalytic layer is an unqualified sample, and the membrane electrode performance cannot be tested.

[0076] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a membrane electrode by plasma etching combined with rotary hot pressing transfer, characterized in that: The following steps are involved: S1, performing plasma discharge etching on the transfer substrate to obtain an etched transfer substrate; S2, stacking and paving a graphite plate, a protective layer, a first pre-treated transfer substrate, a proton exchange membrane, a second pre-treated transfer substrate, a protective layer, and a graphite plate in sequence to form a transfer sample, and performing hot pressing transfer treatment by a rotary hot pressing transfer process to obtain a hot pressed membrane electrode; wherein the first pre-treated transfer substrate is an etched transfer substrate coated with an anode catalyst layer, and the second pre-treated transfer substrate is an etched transfer substrate coated with a cathode catalyst layer; S3, removing the first pre-treated transfer substrate and the second pre-treated transfer substrate on the membrane electrode after hot pressing, pasting carbon paper, sealing the frame, stamping and forming, and obtaining the membrane electrode.

2. The method for preparing a membrane electrode by plasma etching combined with rotary hot pressing transfer as claimed in claim 1, characterized in that: In step S1, the power of the plasma discharge etching process is 50-100 W, the discharge time is 30-150 s, and the gas is argon.

3. The method for preparing a membrane electrode by plasma etching combined with rotary hot pressing transfer as claimed in claim 1, characterized in that: In step S2, the rotary hot pressing transfer process specifically includes: after hot pressing the transfer sample, rotate 60-120° before the next hot pressing, and each transfer sample rotates a total of 360°. The temperature of the hot pressing transfer is 130-160°C, the pressure is 1.0-3.0MPa, and the hot pressing transfer time is 30-90s.

4. The method for preparing a membrane electrode by plasma etching combined with rotary hot pressing transfer as claimed in claim 1, characterized in that: The cathode catalyst is coated on a side close to the proton exchange membrane, and the cathode catalyst is one or two of Pt / C, PtCo / C, and PtNi catalysts; the content of the noble metal in the cathode catalyst ranges from 10 to 70 wt%; the content of the carbon in the cathode catalyst ranges from 30 to 90 wt%.

5. The method for preparing a membrane electrode by plasma etching combined with rotary hot pressing transfer as claimed in claim 1, characterized in that: The anode catalyst is coated on one side close to the proton exchange membrane. The anode catalyst is one or two of Pt / C and PtRu / C catalysts. The content of the noble metal in the anode catalyst ranges from 5 to 30 wt %; the content of the carbon in the anode catalyst ranges from 70 to 95 wt %.

6. The method for preparing a membrane electrode by plasma etching combined with rotary hot pressing transfer as claimed in claim 1, characterized in that: The loading of the noble metal in the cathode catalyst layer is set to 0.2-2.0 mg / cm 2 The loading of the noble metal in the anode catalyst layer is set to 0.05-0.2 mg / cm 2 .

7. The method for preparing a membrane electrode by plasma etching combined with rotary hot pressing transfer as claimed in claim 1, characterized in that: The protective layer is one of PI, PPS and PEN, and the area of ​​the protective layer is greater than or equal to the area of ​​the membrane electrode; the transfer substrate is PTFE film and / or glass fiber paper.

8. The method for preparing a membrane electrode by plasma etching combined with rotary hot pressing transfer as claimed in claim 1, characterized in that: The thickness of the proton exchange membrane is 5 to 30 μm.

9. A membrane electrode, characterized in that: The membrane electrode is prepared by the membrane electrode preparation method according to any one of claims 1 to 8.

10. Use of a membrane electrode as claimed in claim 9 in a fuel cell stack.

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