High-performance binder-free nanofiber membrane electrode and preparation method thereof, fuel cell

Abstract

The application discloses a high-performance binder-free nanofiber membrane electrode and a preparation method and fuel cell thereof, and belongs to the technical field of fuel cells. The preparation method comprises the following steps: performing constant potential treatment on a single cell assembled by a nanofiber membrane electrode under the condition that air is passed through a cathode and hydrogen is passed through an anode, performing nitrogen blowing on the cathode and hydrogen blowing on the anode for a set time after the treatment is completed, then performing cyclic voltammetry scanning on the cathode and the anode under the condition that nitrogen is passed through the cathode and hydrogen is passed through the anode, and the high-performance binder-free nanofiber membrane electrode is obtained; wherein, a cathode catalytic layer of the nanofiber membrane electrode is prepared by an electrostatic spinning method. The preparation method can effectively remove the binder in the nanofiber membrane electrode, significantly improves the utilization rate and catalytic activity of the catalyst and the working performance of the membrane electrode, and is simple and easy to operate.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fuel cells, in particular to a high-performance binder-free nanofiber membrane electrode and a preparation method thereof, and a fuel cell. BACKGROUND

[0002] The information disclosed in the background of the present application is only intended to increase the understanding of the overall background of the present application and should not necessarily be regarded as acknowledging or implying in any form that the information constitutes prior art known to those skilled in the art.

[0003] Fuel cells, especially hydrogen fuel cells, are regarded as a key technology direction to promote energy transformation and achieve sustainable development due to their high energy density, zero pollution emission and other significant advantages, and have received widespread attention worldwide in recent years. However, the large-scale application of current fuel cells still faces significant bottlenecks, the most prominent challenge of which is the high cost. As the core component, Pt-based catalysts account for a large proportion of the total cost of the battery due to resource scarcity and complex preparation process, which greatly limits the commercialization process of fuel cells. Therefore, how to effectively improve the utilization rate of Pt-based catalysts and reduce the Pt consumption per unit energy output has become one of the core issues in this field.

[0004] Under this background, it is recognized as an effective strategy to reduce Pt consumption to construct ordered membrane electrodes, and electrospinning technology has become a common means to construct such membrane electrodes due to its ability to efficiently prepare ordered nanofiber structures. However, it is found in practical applications that the nanofiber electrodes prepared by traditional electrospinning process generally have the problem that the active sites of the catalyst are wrapped by the binder. The binder, while fixing the nanofiber structure, will partially cover or wrap the catalyst particles, resulting in a large number of active sites that cannot fully contact with the reaction gas, ultimately making the actual utilization rate of the catalyst much lower than the theoretical value. This defect seriously restricts the further improvement of the performance of ordered membrane electrodes. SUMMARY

[0005] Therefore, the present application provides a high-performance binder-free nanofiber membrane electrode and a preparation method thereof, and a fuel cell. The present application can provide a nanofiber electrode without binder, effectively expose the active sites of the catalyst, significantly improve the catalyst utilization rate, and further improve the performance of the nanofiber membrane electrode.

[0006] In a first aspect, the present application provides a preparation method of a high-performance binder-free nanofiber membrane electrode, comprising the following steps:

[0007] The single cell of the nanofiber membrane electrode is assembled and subjected to constant potential treatment under the condition that air is passed through the cathode and hydrogen is passed through the anode, and after the treatment is completed, the single cell is purged under the condition that nitrogen is passed through the cathode and hydrogen is passed through the anode for a set time; then, the single cell is subjected to cyclic voltammetry scanning under the condition that nitrogen is passed through the cathode and hydrogen is passed through the anode, and a high-performance binder-free nanofiber membrane electrode is obtained.

[0008] Preferably, the cathode catalytic layer of the nanofiber membrane electrode is prepared by an electrospinning method.

[0009] Preferably, the preparation method of the nanofiber membrane electrode is as follows:

[0010] The nanofiber catalytic layer is prepared by electrospinning, and is transferred to one side of the proton exchange membrane to obtain the cathode catalytic layer; the anode slurry is sprayed on the other side of the proton exchange membrane to prepare the anode catalytic layer, so as to construct the catalyst coated membrane; or, the anode catalytic layer and the cathode catalytic layer are prepared by electrospinning, and are transferred to the two sides of the proton exchange membrane respectively to construct the catalyst coated membrane.

[0011] The catalyst coated membrane is hot-pressed with the gas diffusion layer to obtain the nanofiber membrane electrode.

[0012] Further, the catalyst of the anode catalytic layer and the cathode catalytic layer is independently selected from one or more of a platinum-carbon catalyst, a platinum-based alloy catalyst or a non-noble metal catalyst.

[0013] Preferably, the potential of the constant potential treatment is 0.2-0.4 V.

[0014] Preferably, the time of the constant potential treatment is 40-80 min.

[0015] Preferably, after the constant potential treatment is completed, the single cell is purged under the condition that nitrogen is passed through the cathode and hydrogen is passed through the anode for 15-40 min.

[0016] Preferably, the potential range of the cyclic voltammetry scanning is 0-1.2 V.

[0017] Preferably, the number of scanning cycles of the cyclic voltammetry scanning is 15-30 cycles.

[0018] In a second aspect, the application provides a high-performance binder-free nanofiber membrane electrode prepared by the above preparation method.

[0019] In a third aspect, the application provides a fuel cell comprising the above high-performance binder-free nanofiber membrane electrode.

[0020] Compared with the prior art, the application has the following beneficial effects:

[0021] The present application effectively removes the binder in the nanofiber membrane electrode through three-step treatment of constant potential treatment, purging and cyclic voltammetry scanning on the single cell assembled by the nanofiber membrane electrode, reduces the physical coverage of the binder on the catalyst active sites, significantly improves the utilization rate and catalytic activity of the catalyst, and improves the working performance of the membrane electrode. The preparation method provided by the present application is simple and easy to operate, and can quickly prepare high-performance binder-free nanofiber membrane electrode. The membrane electrode after treatment has more excellent electrochemical performance than the initial membrane electrode. BRIEF DESCRIPTION OF DRAWINGS

[0022] The drawings constituting a part of the specification of the present application are used to provide further understanding of the present application, the illustrative embodiments of the present application and the description thereof are used to explain the present application, and do not constitute improper limitation on the present application. Obviously, for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0023] Figure 1 is the scanning electron microscope picture of the cathode catalytic layer of the nanofiber membrane electrode of the comparative example 1 of the present application;

[0024] Figure 2 is the scanning electron microscope picture of the cathode catalytic layer of the nanofiber membrane electrode of the example 1 of the present application;

[0025] Figure 3 is the BET curve of the example 1 and the comparative example 1 of the present application;

[0026] Figure 4 is the polarization curve of the example 1, the example 2, the comparative examples 1-4 of the present application;

[0027] Figure 5 is the CV curve of the example 1 and the comparative example 1 of the present application;

[0028] Figure 6 is the polarization curve of the example 1 and the comparative example 1 of the present application after the first circle and 30000 circle CV aging. DETAILED DESCRIPTION

[0029] It should be pointed out that the following detailed description is exemplary and is intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as generally understood by those skilled in the art to which the present application belongs.

[0030] Term explanation:

[0031] Potentiostatic treatment: a technical method for electrochemical reaction by controlling the electrode potential constant. Its core is to use a constant potential instrument and other equipment to output current through feedback adjustment, so that the electrode potential is stable at the preset value, avoiding the influence of potential fluctuation on the reaction process. Potentiostatic treatment can ensure that the electrode reaction continues at a specific potential. In the present invention, potentiostatic treatment is used to produce water and remove the binder at high current density.

[0032] Cyclic voltammetry (CV) scan: by applying a triangular waveform potential scan on the working electrode (linearly scanning from the initial potential to the vertex potential, and then scanning back to the initial potential in reverse), the current change curve with potential is recorded (also known as "cyclic voltammogram" or "CV curve").

[0033] Catalyst coated membrane (CCM): catalyst coated membrane is a catalytic layer structure formed by coating catalyst on both sides of the proton exchange membrane, which is the core part of the membrane electrode assembly (MEA).

[0034] Gas diffusion layer (GDL): gas diffusion layer is a porous material layer between bipolar plate and catalyst layer in fuel cell, usually composed of substrate layer and microporous layer. The substrate layer is made of carbon fiber paper, carbon cloth, etc., and the microporous layer is made of carbon powder mixed with hydrophobic agent. Its core functions include: ① supporting the catalyst layer and stabilizing the electrode structure; ② conducting the reaction gas to the surface of the catalyst layer; ③ collecting the electrons generated by the catalyst layer and conducting them to the external circuit; ④ removing the water generated by the reaction to prevent "water flooding" from causing performance degradation.

[0035] Nanofiber membrane electrode: a kind of membrane electrode assembly (MEA) with nanofiber material as the core skeleton or carrier of the catalyst layer.

[0036] The present invention provides a preparation method of a high-performance binder-free nanofiber membrane electrode, comprising the following steps:

[0037] The single cell assembled by the nanofiber membrane electrode is subjected to potentiostatic treatment under the condition that air is passed through the cathode and hydrogen is passed through the anode. After the treatment is completed, the cathode is purged with nitrogen and the anode is purged with hydrogen for a set time. Then, the cyclic voltammetry scan is carried out under the condition that the cathode is purged with nitrogen and the anode is purged with hydrogen, and the high-performance binder-free nanofiber membrane electrode is obtained.

[0038] The cathode catalyst layer of the nanofiber membrane electrode is prepared by electrospinning.

[0039] The present application effectively removes the binder in the nanofiber electrode through a specific processing process, significantly improves the catalyst utilization rate and electrode performance. First, the water produced by the cathode in the constant potential treatment process under H2 / air conditions can dissolve the binder (such as polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid, etc.) in the electrode, reducing the physical coverage of the binder to the catalyst active sites, so that more catalysts directly participate in the electrochemical reaction, and the effective utilization rate of the catalyst is fundamentally improved. Secondly, the purging step under H2 / N2 conditions timely removes the water that dissolves the binder, avoids the problem of catalyst "waterlogging" caused by residual water, maintains the openness of the gas mass transfer channel inside the electrode, and optimizes the transmission efficiency of the reaction gas (hydrogen and oxygen). Finally, the cyclic voltammetry scanning treatment further peels off the outer layer of the catalyst that has been disabled due to waterlogging in the early stage, so that the high-activity catalyst in the inner layer is fully exposed, thereby comprehensively improving the catalytic activity and stability of the electrode, and ultimately obtaining a high-performance binder-free nanofiber membrane electrode.

[0040] In the present application, the preparation method of the nanofiber membrane electrode is as follows:

[0041] The nanofiber catalyst layer is prepared by electrospinning, and is transferred to one side of the proton exchange membrane to obtain a cathode catalyst layer; an anode slurry is sprayed on the other side of the proton exchange membrane to prepare an anode catalyst layer, thereby constructing a catalyst coated membrane; or, the anode catalyst layer and the cathode catalyst layer are prepared by electrospinning, and are transferred to both sides of the proton exchange membrane to construct the catalyst coated membrane.

[0042] The catalyst coated membrane and the gas diffusion layer are hot pressed to form a nanofiber membrane electrode.

[0043] The present application does not make special restrictions on the specific preparation method of the nanofiber membrane electrode, for example, the formula and preparation method of the anode slurry, the formula and preparation method of the cathode spinning slurry, the transfer method, the selection of the proton exchange membrane, and the hot pressing parameters, etc. can be prepared by using the conventional nanofiber membrane electrode in the art.

[0044] The present application does not make special restrictions on the method of assembling the nanofiber membrane electrode into a single cell, and the commonly used method of assembling a single cell in the art can be used.

[0045] In the present application, the catalyst of the anode catalyst layer and the cathode catalyst layer is independently selected from one or more of platinum carbon catalyst, platinum-based alloy catalyst or non-noble metal catalyst. The present application does not make special restrictions on the source and preparation method of the specific catalyst.

[0046] In the present application, the potential of the constant potential treatment is 0.2-0.4 V, and the above potential range ensures that the reaction current density is high enough, and the water (O2+H2→2H2O) generated by the electrochemical reaction can effectively dissolve the binder in the electrode, so that the binder is stripped from the surface of the catalyst and the covered active sites are released. The time of the constant potential treatment is 40-80 min, and more preferably 50-70 min, so as to ensure that the binder is sufficiently dissolved, while avoiding the swelling or falling off of the electrode structure due to long-time water immersion, which affects the mechanical stability of the catalyst layer.

[0047] In the present application, after the constant potential treatment is completed, the nitrogen gas is introduced into the cathode and the hydrogen gas is introduced into the anode, and the blowing is performed for 15-40 min, for example, 15 min, 20 min, 25 min, 30 min, 40 min, etc. After the constant potential treatment, the water for dissolving the binder remains in the electrode surface and pores. If the water is not removed in time, it may cause the catalyst to be "flooded" (i.e., the pores are filled with water, which hinders the transmission of the reaction gas), or the residual binder is re-deposited on the surface of the catalyst. By blowing under the H2 / N2 condition, the water in the electrode surface and inside and the binder dissolved in the water can be quickly removed, and the openness of the gas diffusion channel is restored.

[0048] In the present application, the potential range of the cyclic voltammetry scanning is 0-1.2 V. The lower limit of the potential range is close to the hydrogen evolution potential, and the catalyst surface can be cleaned by the adsorption / desorption reaction of H2 to remove small molecular impurities; the upper limit of the potential range can strip the outer layer of the catalyst which is invalid due to the previous flooding or binder residue by oxidation reaction, and expose the inner layer of the high-activity catalyst which is not covered.

[0049] In the present application, the scanning number of the cyclic voltammetry scanning is 15-30, and more preferably 18-25. A sufficient number of scanning can ensure that the invalid outer layer is fully stripped and the active sites are completely exposed; but too many scanning numbers may cause the catalyst particles to agglomerate or fall off, which reduces the service life of the electrode.

[0050] In the present application, the purity of the nitrogen gas and the hydrogen gas introduced into the cathode and the anode is above 99.99%.

[0051] The present application also provides a high-performance binder-free nanofiber membrane electrode prepared by the above preparation method.

[0052] The present application also provides a fuel cell comprising the above high-performance binder-free nanofiber membrane electrode. The present application does not make special limitations on the specific preparation method of the fuel cell, and the commonly used preparation method of the fuel cell in the art can be used.

[0053] The technical solutions of the present application will be further described below in combination with specific examples. In the following examples, the purity of the hydrogen gas and the nitrogen gas is above 99.99%.

[0054] Example 1

[0055] The embodiment provides a high-performance binder-free nanofiber membrane electrode and a preparation method thereof.

[0056] The specific preparation method is as follows:

[0057] (1) Preparation of cathode spinning slurry: 1.5 g of Pt / C catalyst (Pt content is 60 wt%) is accurately weighed, 4.2 g of 10 wt% Nafion, 7.4 g of isopropyl alcohol and 11.8 g of deionized water are added, and the mixture is uniformly mixed by cell crushing for 10 min, shearing for 20 min and ultrasonic for 40 min. 8.3 g of the uniformly mixed solution is taken, 0.12 g of PAA is added, and stirring is performed for 24 h to obtain a cathode spinning slurry.

[0058] (2) Preparation of a cathode catalyst layer: the temperature is controlled to be lower than 30 DEG C, the humidity is controlled to be lower than 50%, the positive high voltage is 14 kV, the negative high voltage is-2 kV, the liquid outlet flow rate is 0.2 mm / min, and the cathode spinning slurry prepared in step (1) is electrospun for 5 h to obtain a nanofiber catalyst layer; the nanofiber catalyst layer is transferred to a proton exchange membrane under the condition of 150 DEG C and 0.3 MPa to obtain a cathode catalyst layer.

[0059] (4) Preparation of an anode slurry: 0.23 g of Pt / C catalyst (Pt content is 60 wt%) is taken, 1.6 g of deionized water, 0.645 g of 10 wt% Nafion and 30.2 g of ethanol are sequentially added, cell crushing is performed for 45 min, and ultrasonic is performed for 30 min to obtain a spraying slurry.

[0060] (5) The anode slurry is sprayed to the other side of the proton exchange membrane in step (2) to obtain an anode catalyst layer, and a catalyst-coated membrane is constructed.

[0061] (6) The catalyst-coated membrane, a gas diffusion layer and a frame material in step (5) are prepared into a nanofiber membrane electrode by hot pressing, and then a single cell is assembled together with a bipolar plate and a sealing element.

[0062] (7) The single cell obtained in step (6) is subjected to 0.3 V constant potential treatment for 1 h under the condition that air is passed through the cathode and hydrogen is passed through the anode.

[0063] (8) The load is turned off, and then the single cell is purged for 20 min under the condition that nitrogen is passed through the cathode and hydrogen is passed through the anode.

[0064] (9) Then, cyclic voltammetry scanning is performed between 0 and 1.2 V for 20 cycles under the condition that nitrogen is passed through the cathode and hydrogen is passed through the anode to obtain a high-performance binder-free nanofiber membrane electrode.

[0065] Example 2

[0066] The embodiment provides a high-performance binder-free nanofiber membrane electrode and a preparation method thereof.

[0067] The specific preparation method is as follows:

[0068] (1) Preparation of cathode spinning slurry: 1.5 g of Pt / C catalyst (Pt content is 60 wt%) is accurately weighed, 4.2 g of 10 wt% Nafion, 7.4 g of isopropyl alcohol and 11.8 g of deionized water are added, cell crushing is performed for 10 min, shearing is performed for 20 min, and ultrasonic is performed for 40 min to uniformly mix the mixture, 8.3 g of the uniformly mixed solution is taken, 0.12 g of PAA is added, stirring is performed for 24 h, and the cathode spinning slurry is obtained.

[0069] (2) Preparation of a cathode catalyst layer: the temperature is controlled to be lower than 30 DEG C, the humidity is controlled to be lower than 50%, the positive high voltage is 14 kV, the negative high voltage is -2 kV, the liquid flow rate is 0.2 mm / min, the cathode spinning slurry prepared in step (1) is used for electrospinning for 5 h, and a nanofiber catalyst layer is obtained; the nanofiber catalyst layer is transferred to one side of a proton exchange membrane under the condition that the temperature is 150 DEG C and the pressure is 0.3 MPa, and a cathode catalyst layer is obtained.

[0070] (3) Preparation of anode spinning slurry: 1.5 g of Pt / C catalyst (Pt content is 60 wt%) is accurately weighed, 4.2 g of 10 wt% Nafion, 7.4 g of isopropyl alcohol and 11.8 g of deionized water are added, cell crushing is performed for 10 min, shearing is performed for 20 min, and ultrasonic is performed for 40 min to uniformly mix the mixture, 8.3 g of the uniformly mixed solution is taken, 0.12 g of PAA is added, stirring is performed for 24 h, and the cathode spinning slurry is obtained.

[0071] (4) The temperature is controlled to be lower than 30 DEG C, the humidity is controlled to be lower than 50%, the positive high voltage is 14 kV, the negative high voltage is -2 kV, the liquid flow rate is 0.2 mm / min, the anode spinning slurry prepared in step (3) is used for electrospinning for 1 h, and a nanofiber catalyst layer is obtained; the nanofiber catalyst layer is transferred to the other side of a proton exchange membrane under the condition that the temperature is 150 DEG C and the pressure is 0.3 MPa, and an anode catalyst layer is obtained, that is, a catalyst-coated membrane is constructed.

[0072] (5) The catalyst-coated membrane of step (4), a gas diffusion layer and a frame material are prepared into a nanofiber membrane electrode through hot pressing, and then the nanofiber membrane electrode is assembled into a single cell together with a bipolar plate and a sealing element.

[0073] (6) The single cell obtained in step (5) is subjected to 0.3 V constant potential treatment for 1 h under the condition that air is passed through the cathode and hydrogen is passed through the anode.

[0074] (7) After the load is closed, the cathode is purged with nitrogen and the anode is purged with hydrogen for 20 min.

[0075] (8) Then, cyclic voltammetry is performed between 0 and 1.2 V for 20 cycles under the condition that the cathode is purged with nitrogen and the anode is purged with hydrogen, to obtain a high-performance binder-free nanofiber membrane electrode.

[0076] Comparative Example 1

[0077] This comparative example differs from Example 1 in that steps (7) to (9) are not performed.

[0078] Comparative Example 2

[0079] This comparative example differs from Example 1 in that step (9) is not performed.

[0080] Comparative Example 3

[0081] This comparative example differs from Example 1 in that steps (7) to (8) are not performed.

[0082] Comparative Example 4

[0083] This comparative example differs from Example 1 in that the constant potential treatment potential in step (7) is increased to 0.5 V.

[0084] Test Example

[0085] 1. Scanning Electron Microscope Test:

[0086] The single cell after treatment in Example 1 was disassembled to expose the cathode catalyst layer, and was subjected to scanning electron microscope test together with the catalyst coating film of step (5) of Comparative Example 1. The scanning electron microscope test results of the cathode catalyst layers of Comparative Example 1 and Example 1 are shown in Figure 1 and Figure 2 , respectively.

[0087] As can be clearly seen from the figures, the binder is removed from the cathode catalyst layer after treatment in steps (7) to (9) of Example 1, and the porosity is increased.

[0088] 2. BET Test:

[0089] The surface area of the disassembled cathode catalyst layer of Example 1 and the cathode catalyst layer of Comparative Example 1 was analyzed using a specific surface area analyzer (BET), and the results are shown in Figure 3 . As can be seen from the figure, the BET surface area and the porosity are increased after removal of the binder.

[0090] 3. Polarization Curve Test:

[0091] The single cells after the treatment of Examples 1-3 and the single cells of Comparative Examples 1-3 were tested under fixed gas amount (air and hydrogen for anode and cathode atmosphere respectively), temperature and back pressure, and the working condition points were selected as 0.2 A / cm 2 , 0.4 A / cm 2 , 0.6 A / cm 2 ……4.0 A / cm 2 (current density corresponding to 0.4 V voltage) and open circuit voltage (OCV), and the residence time of each working condition point was ≥2 min, and the test results are shown in Figure 4 .

[0092] As can be seen from the figure, the performance of Example 1 is basically the same as that of Example 2, both of which are much higher than that of Comparative Example 1, indicating that the preparation of the anode catalytic layer by spraying or electrospinning process has little effect on the performance, and the performance is significantly improved after removing the binder. As can be seen from the comparison between Example 1 and Comparative Example 2, if there is no cyclic voltammetry scanning, the performance of the catalyst will decrease, but the decrease is small. The performance of Comparative Example 3 is not much different from that of Comparative Example 1, indicating that the cyclic voltammetry scanning alone has little effect on the performance of the nanofiber membrane electrode. The performance of Example 1 and Comparative Example 4 is quite different, while the performance of Comparative Example 1 and Comparative Example 4 is basically the same, indicating that the high potential treatment does not completely remove the binder.

[0093] 4. CV curve test:

[0094] After the completion of “3. Polarization curve test”, the air was turned off, and a large flow of nitrogen was used to replace the air in the tube. The anode / cathode was H2 / N2 purging, and when the open circuit voltage was reduced to below 0.2 V, the cyclic voltammetry test was performed. The anode of the nanofiber membrane electrode assembled from Example 1 and Comparative Example 1 was connected to H2 with a relative humidity of 100%, and the cathode was connected to N2 with a relative humidity of 100%. The cyclic voltammetry test was performed under fixed gas amount, temperature and back pressure. During the test, the cathode was the working electrode, and the anode was the counter electrode and reference electrode. The cathode of the single cell was tested. After the CV curve was stable, it was recorded, and the results are shown in Figure 5 .

[0095] As can be seen from the figure, the electrochemical active area (ECSA) of the membrane electrode obtained from Example 1 is greater than that of the membrane electrode obtained from Comparative Example 1, indicating that after removing the binder, the three-phase interface of the membrane electrode increases.

[0096] 5. Durability test:

[0097] The single cell after the treatment of Example 1 and the single cell of Comparative Example 1 were operated at a constant voltage of 0.6 V for 200 h. According to the situation, the polarization test was inserted to judge the attenuation process of the membrane electrode, and the results are shown in Figure 6 .

[0098] As can be seen from the figures, the stability of the membrane electrode of Example 1 is stronger, and the performance attenuation after 30000 cycles of CV aging is much lower than that of Comparative Example 1 without removing the binder.

[0099] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. The present application can be variously changed and modified by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing a high-performance binder-free nanofiber membrane electrode, characterized by, Comprising the following steps: The single cell assembled by the nanofiber membrane electrode is subjected to constant potential treatment under the condition that air is passed through the cathode and hydrogen is passed through the anode, and after the treatment is completed, the cathode is purged with nitrogen and the anode is purged with hydrogen for a set time; then, cyclic voltammetry scanning is performed under the condition that nitrogen is passed through the cathode and hydrogen is passed through the anode, thereby obtaining a high-performance binder-free nanofiber membrane electrode; The potential of the constant potential treatment is 0.2-0.4 V; the time of the constant potential treatment is 40-80 min; After the constant potential treatment is completed, the cathode is purged with nitrogen and the anode is purged with hydrogen for 15-40 min; The cathode catalytic layer of the nanofiber membrane electrode is prepared by electrospinning.

2. The production method according to claim 1, wherein The preparation method of the nanofiber membrane electrode is as follows: A nanofiber catalytic layer is prepared by electrospinning, and is transferred to one side of a proton exchange membrane to obtain a cathode catalytic layer; an anode slurry is sprayed on the other side of the proton exchange membrane to prepare an anode catalytic layer, thereby constructing a catalyst-coated membrane; Alternatively, an anode catalytic layer and a cathode catalytic layer are prepared by electrospinning, and are transferred to both sides of a proton exchange membrane to construct a catalyst-coated membrane; The catalyst-coated membrane is hot-pressed with a gas diffusion layer to obtain a nanofiber membrane electrode.

3. The production method according to claim 2, wherein The catalyst of the anode catalytic layer and the cathode catalytic layer is each independently selected from one or more of a platinum-carbon catalyst, a platinum-based alloy catalyst, or a non-noble metal catalyst.

4. The production method according to claim 1, wherein The potential range of the cyclic voltammetry scanning is 0-1.2 V.

5. The production method according to claim 1, wherein The number of scanning cycles of the cyclic voltammetry scanning is 15-30 cycles.

6. A high-performance binder-free nanofiber membrane electrode prepared by the preparation method of any one of claims 1-5.

7. A fuel cell comprising the high-performance binder-free nanofiber membrane electrode of claim 6.

Images