CN111952599A

CN111952599A - High-stability proton exchange membrane fuel cell nanofiber electrode and preparation method and application thereof

Info

Publication number: CN111952599A
Application number: CN201910399664.2A
Authority: CN
Inventors: 侯明; 齐满满; 邵志刚
Original assignee: Dalian Institute of Chemical Physics of CAS
Current assignee: Dalian Institute of Chemical Physics of CAS
Priority date: 2019-05-14
Filing date: 2019-05-14
Publication date: 2020-11-17
Anticipated expiration: 2039-05-14
Also published as: CN111952599B

Abstract

The invention discloses a preparation method of a high-stability Proton Exchange Membrane Fuel Cell (PEMFC) nanofiber electrode. The electrode fiber framework prepared by the invention has the capability of conducting protons, and the high-activity catalyst is exposed at the outer side of the fiber framework, so that a transmission path of protons and electrons is ensured, and the larger porosity is favorable for the transfer of reaction substances. The electrode prepared by the method has the characteristics of low catalyst consumption, high catalyst utilization rate, long service life, easiness in amplification and the like.

Description

High-stability proton exchange membrane fuel cell nanofiber electrode and preparation method and application thereof

Technical Field

The invention belongs to the field of proton exchange membrane fuel cells, and particularly relates to a method for preparing a high-stability nanofiber electrode by an electrostatic spinning technology and application of the prepared high-stability nanofiber electrode in a membrane electrode component of a fuel cell.

Background

With the transient exploitation and use of fossil energy by human beings, the problems of energy shortage and environmental pollution caused by the fossil energy are increasingly highlighted, and clean energy becomes the ultimate appeal for human beings. The chemical heat of hydrogen energy is high, and combustion products only contain water and heat, so that the hydrogen energy is the cleanest energy in the world. The fuel cell is an electrochemical conversion device and has the characteristics of high energy conversion efficiency, environmental friendliness and the like. The types of the fuel cells can be divided into a plurality of types according to the types of electrolytes, wherein the Proton Exchange Membrane Fuel Cell (PEMFC) has wide application prospects in the fields of fixed power stations, public transportation, aerospace and underwater submarines by virtue of the advantages of low-temperature quick start, high energy density, environmental friendliness and the like. However, to realize commercialization of proton exchange membrane fuel cells, two bottleneck problems of lifetime and cost need to be solved. According to the U.S. department of energy solution, one is to reduce the amount of Pt-based catalyst and the other is to increase the activity of Membrane Electrode (MEA) components. The MEA is a core component of the PEMFC, and is a site where electrochemical reactions occur, and its material and microstructure directly affect the cost and lifetime of the PEMFC. The conventional MEA production method mainly includes a gas diffusion electrode (GDE type) in which a catalyst is supported on a gas diffusion layer and a thin-layer membrane-electrode (CCM type) in which a catalyst is supported on a proton exchange membrane, but has problems of high catalyst support amount, low catalyst utilization rate, and the like.

The electrostatic spinning technology is a method for preparing nano fibers with large specific surface area in batches; in the electrostatic spinning process, a Taylor cone is formed at the tip of a nozzle by a polymer or a melt under the action of high-voltage static electricity, and when electrostatic repulsion overcomes surface tension, jet flow is formed and finally solidified into nano fibers on a receiver. Zhang et al, university of Van der Bambo, first proposed mixing a Pt/C catalyst and Nafion solution and preparing a porous structure Cathode catalyst layer using an electrospinning technique (Wenjing Zhang, electrospinning Pt-C Catalysts in a Nanofiber Fuel Cell Cathe, Winter 2010: 51). The Chinese patent application 201410624103.5 also proposes a preparation method of preparing a cathode catalyst layer with ultra-low Pt loading capacity by mixing a Pt/C catalyst and a Nafion solution and carrying out electrostatic spinning, wherein the Pt loading capacity of the cathode catalyst layer is 0.056mg cm^-2When the maximum power density under the hydrogen-air condition is still 561mW cm^-2. It says thatThe structure of the nanofiber electrode plays an important role in reducing the catalyst loading capacity and improving the catalyst utilization rate. However, the preparation of the catalyst layer by electrostatic spinning requires the addition of high molecular polymer to enhance the spinnability of the catalyst slurry, but the high molecular polymer is easily hydrolyzed under the working condition of the PEMFC, so that the nanofiber electrode structure collapses, the activity of the MEA is reduced, and the requirement of the PEMFC for long-time operation cannot be met.

Disclosure of Invention

The invention aims to solve the problems of high catalyst loading, low catalyst utilization rate and the like of the traditional MEA (membrane electrode assembly), and provides a method for preparing a nanofiber electrode by electrostatic spinning, wherein a fiber framework has proton conduction capability, a high-activity catalyst is exposed at the outer side of the fiber framework, a proton and electron transmission path is ensured, and the high porosity is favorable for transferring reaction substances, so that a foundation is provided for constructing a stable three-phase reaction interface. Meanwhile, aiming at the problem that the structure of the nanofiber electrode structure is easy to collapse under the working condition of the PEMFC, the method is provided that at least one high-molecular polymer is added into catalyst slurry, and the polymer in the catalyst layer is subjected to chemical reaction by adopting a heating method to enhance the stability of the structure. In order to achieve the purpose, the invention adopts the following technical scheme:

the invention provides a preparation method of a high-stability nanofiber electrode, which comprises the steps of dispersing a catalyst, a Nafion solution and a high-molecular polymer in a solvent by ultrasonic dispersion, and stirring to obtain catalyst slurry; preparing the prepared catalyst slurry into a porous catalyst layer with a nanofiber structure by an electrostatic spinning technology; the catalytic layer is heated to improve the structural stability, and is transferred to one side or two sides of the proton exchange membrane by a hot pressing method.

The method comprises the following specific steps:

(1) ultrasonically dispersing a catalyst and a Nafion solution in a solvent for 1-4h to uniformly disperse the catalyst, then adding a high molecular polymer, and stirring for 12-48h to obtain catalyst slurry;

(2) spinning the catalyst slurry by adopting an electrostatic spinning technology to obtain a catalyst layer precursor;

(3) heating the catalyst layer precursor at 80-200 ℃ for 30-300 min to obtain a catalyst layer;

(4) transferring the catalyst layer to one side or both sides of a proton exchange membrane by adopting a hot pressing method to obtain a nanofiber electrode of the proton exchange membrane fuel cell; the hot pressing temperature is 130-145 ℃, the hot pressing pressure is 0.1-2 MPa, and the hot pressing time is 100-300 s.

Based on the technical scheme, the preferable heating atmosphere is one of air, nitrogen and argon, and the generated reaction comprises one of esterification reaction, acetal reaction, neutralization reaction and vitrification. The hydroxyl-containing high molecular polymer and the carboxylic acid-containing high molecular polymer are subjected to esterification reaction in the heat treatment process, such as polyacrylic acid (PAA), polyvinyl alcohol (PVA), cyclodextrin and the like; the high molecular polymer containing hydroxyl groups and the high molecular polymer containing aldehyde groups undergo an acetal reaction during heat treatment, such as polyvinyl alcohol (PVA) and glutaraldehyde; the hydroxyl group-containing polymer and the ether bond-containing polymer form a complex in the heat treatment, such as polyacrylic acid (PAA) and ethylene oxide.

Based on the technical scheme, the preferable catalyst is one or two of Pt/C, PtPd/C, PtFe/C, PtCo/C, PtNi/C, PtCu/C; in the catalyst, the mass fraction of Pt is 10-70 wt.%; the mass ratio of the solid-phase substance catalyst, the perfluorinated sulfonic acid resin of the Nafion solution and the high molecular polymer in the catalyst slurry is 50:25:25-68:23: 9; the viscosity of the catalyst slurry is 50-200 cp.

Based on the above technical solution, the preferable high molecular polymer is one or at least two of polyacrylic acid (PAA), Cyclodextrin (CD), polyvinyl alcohol (PVA), polyethylene oxide (PEO), glutaraldehyde, polyvinylpyrrolidone (PVP), hydroxypropyl cellulose (HPC), Polyacrylonitrile (PAN), polyvinylidene fluoride (PVDF), Polytetrafluoroethylene (PTFE), and Polyaniline (PANI).

Based on the technical scheme, the preferable environment parameters of electrostatic spinning are as follows: the temperature is 10-30 ℃, and the relative humidity is 10-50% RH; the control parameters are as follows: the feeding speed of the catalyst slurry is 0.3mL/h-1.2mL/h, the voltage is 8kV-20kV, the rotating speed of the rotary drum receiver is 100rpm/min-300rpm/min, the diameter of the needle is 10G-25G, and the distance between the needle and the receiver is 8cm-15 cm.

Based on the technical scheme, the preferable mass ratio of the catalyst to the solvent is 1:2-5, and the solvent is a mixed solution of water and isopropanol; the mass ratio of water to isopropanol in the mixed solution is 1: 3-10.

Based on the technical scheme, the thickness of the catalytic layer is preferably 1-5 μm.

The invention also provides a high-stability nanofiber electrode obtained by the preparation method; the catalyst layer of the nanofiber electrode is of an unordered three-dimensional porous fiber structure, the catalyst is exposed on the outer surface of a fiber framework, the fiber surface is uneven, the diameter of a fiber in the nanofiber electrode is 200nm-800nm, the porosity of the catalyst layer of the nanofiber electrode is 25% -75%, the catalyst is uniformly coated on the outer side of the nanofiber framework, and the nanofiber has proton conduction capability.

The invention further provides an application of the high-stability nanofiber electrode in a membrane electrode of a proton exchange membrane fuel cell.

Advantageous effects

1. The invention provides that at least one high molecular polymer is added into the catalyst slurry to be used as a binder of the catalyst slurry, so that the hydrolysis of the polymer under the working condition of the fuel cell can be effectively relieved, and the stability of the fuel cell is further improved.

2. The invention provides a method for heating a nanofiber catalyst layer, which can enable high-molecular polymers to react with each other, so that the structural stability of a nanofiber electrode is improved.

3. The nanofiber electrode prepared by the method has the advantages that the fiber framework is favorable for proton conduction, and the high-activity catalyst is exposed at the outer side of the fiber framework, so that the utilization rate of the catalyst is improved; meanwhile, the nanofiber electrode has a good pore structure and high porosity, and is beneficial to the transfer of reactants and the timely discharge of water as a reaction product.

Drawings

Fig. 1 is an SEM image of the Pt/C nanofiber catalytic layer prepared in comparative example 1.

Fig. 2 is an initial battery performance curve of the Pt/C nanofiber electrode prepared in comparative example 1 and a battery performance curve graph after constant current discharge.

FIG. 3 is a constant current discharge curve diagram of a Pt/C nanofiber electrode prepared in comparative example 1.

Fig. 4 is an SEM image of the Pt/C nanofiber catalytic layer prepared in example 1 of the present invention.

Fig. 5 is an SEM image of the Pt/C nanofiber catalytic layer prepared in example 1 of the present invention after esterification.

Fig. 6 is an initial battery performance curve of the Pt/C nanofiber electrode prepared in example 1 of the present invention and a battery performance curve graph after constant current discharge.

FIG. 7 is a constant current discharge curve diagram of the Pt/C nanofiber electrode prepared in example 1 of the present invention.

FIG. 8 is a performance curve diagram of a PtCo/C nanofiber electrode cell prepared in example 2 of the present invention.

FIG. 9 is a graph showing the discharge performance of PtFe/C and PtPd/C nanofiber electrodes prepared in example 3 of the present invention.

FIG. 10 is a graph of discharge performance of the nanofiber electrode with PVA as the binder prepared in example 4 of the present invention.

FIG. 11 is a graph of discharge performance of the nanofiber electrode with PVP as binder prepared in example 5 of the present invention.

FIG. 12 is a graph of discharge performance of the nanofiber electrode with PVA/PTFE as the binder prepared in example 6 of the present invention.

FIG. 13 is a graph of the discharge performance of nanofiber electrode prepared in example 7 of the present invention using PAN/PANI as binder.

FIG. 14 is a graph of discharge performance of nanofiber electrodes prepared according to example 8 of the present invention and using PVA/HPC as a binder.

FIG. 15 is a graph of discharge performance of nanofiber electrode prepared by using PAA/PVDF as a binder in example 9 of the present invention.

FIG. 16 is a graph of discharge performance of nanofiber electrode prepared by using PAA/PEO as a binder in example 10 of the present invention.

Detailed Description

The following examples are further illustrative of the present invention while protecting obvious modifications and equivalents.

Comparative example 1

0.1g of 40 wt.% Pt/C catalyst and 0.8g of 5 wt.% Nafion solution are weighed, 0.08g of water and 0.3g of isopropanol are added, ultrasonic mixing is carried out, then 0.02g of polyacrylic acid high molecular polymer is added, and stirring is carried out for 36 hours, so as to obtain catalyst slurry with the viscosity of 100 cp. The catalyst layer is prepared by adopting an electrostatic spinning technology and named as a single polymer nanofiber electrode. The environmental parameters of electrostatic spinning are 15 ℃ of temperature and 30% RH of relative humidity; the control parameters are as follows: the slurry feed rate was 0.8mL/h, the voltage was 12kV, the rotational speed of the drum receiver was 120rpm/min, the diameter of the needle was 22G, and the distance from the needle to the receiver was 12 cm. The Pt loading amount is 0.1mg cm by controlling the spinning time^-2The catalytic layer of (2) has a thickness of about 2 μm. Finally, the catalytic layer is transferred to

211, hot-pressing at 140 deg.C under 0.2-0.5MPa for 120-240s, and preparing single-side membrane electrode. The anode was evaluated for electrochemical performance on a single cell evaluation apparatus using a commercial gas diffusion electrode.

The morphology of the catalytic layer obtained by electrostatic spinning is shown in fig. 1, and it can be seen from fig. 1 that the catalytic layer is in a nanofiber shape, the diameter is about 400nm, and the Pt/C catalyst is uniformly coated on the high molecular polymer skeleton. Pt loading of 0.1mg cm at the cathode^-2While, the cell had 500mW cm^-2Output power of 150h 2A cm^-2The maximum power density of the battery after constant current discharge is 87mWcm^-2Only 17% of the initial performance (as shown in FIG. 2, the cell operating conditions were 65 ℃ C., 100% gas wettability; H)₂Flow 125mL min^-1(ii) a Air flow 800mL min^-1. Cell back pressure 0.5 bar). Stability tests were performed on a single polymer nanofiber electrode in constant current mode, as shown in FIG. 3 (cell operating conditions: cell temperature 65 ℃; gas wettability 100%; H)₂Flow 125mL min^-1；O₂Flow 250mL min^-1The back pressure of the battery is 0.5bar, and the discharge current is 2A cm^-2。)

Example 1

Weighing 0.1g of 40 wt.% Pt/C catalyst and 0.8g of 5 wt.% Nafion solution, adding 0.08g of water and 0.3g of isopropanol, ultrasonically mixing uniformly, and then adding 0.02g of two high molecular polymers of polyacrylic acid and polyvinyl alcohol, wherein the mass ratio of the polyacrylic acid to the polyvinyl alcohol is 1:1, stirring for 36h to obtain a catalyst slurry with a viscosity of 110 cp. The catalyst layer was prepared by electrospinning, the environmental parameters and control parameters of electrospinning were the same as in comparative example 1. The Pt loading amount is 0.1mg cm by controlling the spinning time^-2The catalytic layer of (2) has a thickness of about 2 μm. The temperature of the heat treatment of the prepared catalyst layer is 140 ℃, the treatment time is 60min, and the treatment atmosphere is air, so that the high molecular polymer generates esterification reaction. Finally, the heat-treated catalytic layer is transferred to

The catalytic layer morphology of the two high molecular polymers obtained by electrostatic spinning is shown in fig. 4 and 5, and has no obvious difference from fig. 1 in morphology. FIG. 4 is a graph showing the morphology of the catalytic layer prepared in this example without being subjected to heat treatment; fig. 5 is a morphology diagram of the catalytic layer after the esterification reaction occurs by the heat treatment, and the structure of the catalytic layer is not significantly different from that before the esterification reaction occurs by the heat treatment, which shows that the structure of the catalytic layer is not damaged by the heat treatment. This example prepared a Pt loading of 0.1mg cm^-2The cell has an electrode of 547mW cm^-2Output power of 150h 2A cm^-2The maximum power density of the battery after constant current discharge is 402mW cm^-2Still has the initial performance of 73 percent (as shown in figure 6, the operation conditions of the battery are that the battery temperature is 65 ℃, the gas wettability is 100 percent, H₂Flow 125mL min^-1(ii) a Air flow 800mL min^-1. The cell was back-pressed at 0.5 bar. ) The esterified electrode was subjected to stability testing in constant current mode, as shown in fig. 7 (cell operating conditions)Comprises the following steps: the temperature of the battery is 65 ℃; the gas wettability is 100%; h₂Flow 125mL min^-1；O₂Flow 250mL min^-1The back pressure of the battery is 0.5bar, and the discharge current is 2A cm^-2. ) The results of this example are compared with comparative example 1, which shows that the invention adds two kinds of high molecular polymers as the binder of the catalyst slurry in the catalyst slurry, and simultaneously, adopts the heating treatment method to make the high molecular polymers have chemical reaction, thereby significantly improving the stability of the nanofiber electrode structure, avoiding the high molecular polymers from being hydrolyzed under the operating condition of PEMFC to cause the collapse of the nanofiber electrode structure, and further reducing the activity of MEA, which does not meet the requirement of PEMFC for long-time operation.

Example 2

Weighing 0.11g of PtCo/C catalyst, wherein the mass fraction of Pt is 45%, adding 0.8g of 5 wt.% Nafion solution, adding 0.1g of water and 0.35g of isopropanol, carrying out ultrasonic mixing uniformly, then adding 0.02g of cyclodextrin and polyacrylic acid high molecular polymer, wherein the mass ratio of the cyclodextrin to the polyacrylic acid is 1: stirring for 24h to obtain a catalyst slurry with a viscosity of 90 cp. Then preparing a catalyst layer by adopting an electrostatic spinning technology, wherein the environmental parameters of the electrostatic spinning are as follows: temperature 15 ℃, relative humidity 30% RH; the control parameters are as follows: the slurry feed rate was 0.8mL/h, the voltage was 12.5kV, the rotational speed of the drum receiver was 110rpm/min, the needle diameter was 20G, and the distance between the needle and the receiver was: 12 cm. The Pt loading amount of 0.08mgcm is obtained by controlling the spinning time^-2The catalytic layer (2) has a thickness of about 1.5 μm. The temperature of the prepared catalytic layer after heat treatment is 120 ℃, the treatment time is 60min, and the treatment atmosphere is air, so that the high molecular polymer in the catalytic layer is subjected to neutralization reaction. Finally, the heat-treated catalytic layer is transferred to

211, hot-pressing at 135 deg.C under 0.2-0.5MPa for 120-240s, and preparing single-side membrane electrode. The anode was evaluated for electrochemical performance on a single cell evaluation unit using a commercial gas diffusion electrode under cell operating conditions of: the temperature of the battery is 65 ℃; the gas wettability is 100%; h₂Flow 125mLmin^-1(ii) a Air flow 800mL min^-1The cell was back-pressed at 0.5 bar. The obtained full cell performance graph is shown in fig. 8, in this example, the nanofiber electrode with the alloy type catalyst layer was successfully prepared by the electrostatic spinning method, and the full cell test indicates that the maximum power density of the nanofiber electrode with the alloy type catalyst layer is 450mW cm^-2。

Example 3

Weighing 0.1g of each of PtFe/C and PtPd/C catalysts, wherein the mass fraction of Pt is respectively 25% and 55%, 0.5g of 10 wt% Nafion solution is added, 0.15g of water and 0.55g of isopropanol are added, ultrasonic mixing is carried out uniformly, then 0.04g of polyvinyl alcohol and glutaraldehyde high molecular polymer are added, and the mass ratio of the polyvinyl alcohol to the glutaraldehyde is 1:1, stirring for 32h to obtain a catalyst slurry with a viscosity of 120 cp. Then preparing a catalyst layer by adopting an electrostatic spinning technology, wherein the environmental parameters of the electrostatic spinning are as follows: temperature 15 ℃, relative humidity 20% RH; the control parameters are as follows: the slurry feed rate was 1mL/h, the voltage was 13kV, the rotational speed of the drum receiver was 80rpm/min, the needle diameter was 20G, and the distance between the needle and the receiver was: 13 cm. The Pt loading amount is 0.15mg cm by controlling the spinning time^-2The catalyst layer of (1). The temperature of the prepared catalyst layer after heat treatment is 100 ℃, the treatment time is 100min, and the treatment atmosphere is argon, so that the high molecular polymer in the catalyst layer is subjected to an acetal reaction. Finally, the heat-treated catalytic layer is transferred to

211, hot-pressing at 135 deg.C under 0.2-0.5MPa for 120-200s, and preparing single-side membrane electrode. The anode was evaluated for electrochemical performance on a single cell evaluation unit using a commercial gas diffusion electrode under cell operating conditions of: the temperature of the battery is 65 ℃; the gas wettability is 100%; h₂Flow 125mL min^-1(ii) a Air flow 800mL min^-1The cell back pressure was 0.5bar, and a full cell performance graph was obtained as shown in fig. 9. This example shows that the nanofiber electrode of the multicomponent alloy type catalytic layer can be prepared by the electrospinning method as well, and the full cell test shows that the nanofiber electrode of the multicomponent alloy type catalytic layerMaximum power density of 495mW cm^-2。

Example 4

0.15g of 40 wt% Pt/C catalyst and 1.2g of 5 wt% Nafion solution are weighed, 0.12g of water and 0.4g of isopropanol are added, ultrasonic mixing is carried out, 0.03g of polyvinyl alcohol high molecular polymer is added, and stirring is carried out for 36 hours to obtain catalyst slurry with the viscosity of 180 cp. Preparing a catalyst layer by adopting an electrostatic spinning technology, wherein the environmental parameters of the electrostatic spinning are that the temperature is 25 ℃, and the relative humidity is 10% RH; the control parameters are as follows: the slurry feed rate was 1.2mL/h, the voltage was 20kV, the rotational speed of the drum receiver was 200rpm/min, the needle diameter was 15G, and the distance from the needle to the receiver was 12 cm. The Pt loading amount is 0.2mgcm by controlling the spinning time^-2The catalytic layer of (2), the catalytic layer having a thickness of about 4 μm. Hot-pressing transfer of catalytic layer to

211, hot-pressing at 140 deg.C under 0.2-0.5MPa for 120-240s, and preparing single-side membrane electrode. The anode was evaluated for electrochemical performance on a single cell evaluation apparatus using a commercial gas diffusion electrode. The battery operating conditions were: the temperature of the battery is 65 ℃; the gas wettability is 100%; h₂Flow 125mL min^-1(ii) a Air flow 800mL min^-1The cell back pressure was 0.5bar, and a full cell performance graph was obtained as shown in fig. 10. This example shows that polyvinyl alcohol as a binder for catalyst slurry can be prepared by electrospinning, and full cell tests show that the maximum power density of the electrode prepared in this example is 569mW cm^-2。

Example 5

Weighing 0.1g of PtNi/C catalyst, wherein the mass fraction of Pt is 30%, adding 1g of 5 wt.% Nafion solution, adding 0.12g of water and 0.3g of isopropanol, ultrasonically mixing uniformly, adding 0.02g of polyvinylpyrrolidone, and stirring for 36 hours to obtain catalyst slurry with the viscosity of 150 cp. Preparing a catalyst layer by adopting an electrostatic spinning technology, wherein the environmental parameters of electrostatic spinning are that the temperature is 25 ℃, and the relative humidity is 25% RH; the control parameters are as follows: the slurry feeding rate is 1mL/h, the voltage is 15kV, the rotating speed of the rotary drum receiver is 200rpm/min, the diameter of the needle is 18G, and the distance between the needle and the receiverIs 10 cm. The Pt loading amount is 0.12mg cm by controlling the spinning time^-2The catalytic layer of (2) has a thickness of about 2 μm. Hot-pressing transfer of catalytic layer to

211, hot-pressing at 135 deg.C under 0.2-0.5MPa for 100-260s to obtain single-side membrane electrode. The anode was evaluated for electrochemical performance on a single cell evaluation apparatus using a commercial gas diffusion electrode. The battery operating conditions were: the temperature of the battery is 65 ℃; the gas wettability is 100%; h₂Flow 125mL min^-1(ii) a Air flow 800mL min^-1The cell back pressure was 0.5bar, and a full cell performance graph was obtained as shown in fig. 11. This example shows that polyvinylpyrrolidone as a catalyst slurry binder can also be prepared by electrospinning, and full cell testing shows that the maximum power density of the electrode of this example is 522mW cm^-2。

Example 6

Weighing 0.1g of PtCo/C catalyst, wherein the mass fraction of Pt is 55%, adding 1g of 5 wt.% Nafion solution, adding 0.12g of water and 0.3g of isopropanol, ultrasonically mixing uniformly, adding 0.03g of polyvinyl alcohol and polytetrafluoroethylene high molecular polymer, wherein the mass ratio of the polyvinyl alcohol to the polytetrafluoroethylene is 1:1, and stirring for 36 hours to obtain catalyst slurry with the viscosity of 150 cp. Preparing a catalyst layer by adopting an electrostatic spinning technology, wherein the environmental parameters of electrostatic spinning are that the temperature is 25 ℃, and the relative humidity is 25% RH; the control parameters are as follows: the slurry feed rate was 1mL/h, the voltage was 15kV, the rotational speed of the drum receiver was 200rpm/min, the diameter of the needle was 20G, and the distance between the needle and the receiver was 10 cm. The Pt loading amount is 0.15mg cm by controlling the spinning time^-2The catalytic layer of (2) has a thickness of about 2 μm. The temperature of the prepared catalyst layer after heat treatment is 200 ℃, the treatment time is 300min, and the treatment atmosphere is air, so that the high molecular polymer in the catalyst layer is vitrified. Finally, the catalytic layer is transferred to

211 film with the hot pressing temperature of 135 ℃, the hot pressing pressure of 0.2-0.5MPa and the hot pressing time of 100-30And 0s, preparing the single-side membrane electrode. The anode was evaluated for electrochemical performance on a single cell evaluation apparatus using a commercial gas diffusion electrode. The battery operating conditions were: the temperature of the battery is 65 ℃; the gas wettability is 100%; h₂Flow 125mL min^-1(ii) a Air flow 800mL min^-1The cell back pressure was 0.5bar, and a full cell performance graph was obtained as shown in fig. 12. This example shows that polyvinyl alcohol and polytetrafluoroethylene as catalyst slurry binders can also be prepared by electrospinning, and full cell testing shows that the maximum power density of the electrode of this example is 484mW cm^-2。

Example 7

Weighing 0.1g of PtCu/C catalyst, wherein the mass fraction of Pt is 60%, adding 1g of 5 wt.% Nafion solution, adding 0.12g of water and 0.3g of isopropanol, ultrasonically mixing uniformly, adding 0.036g of polyacrylonitrile and polyaniline high-molecular polymer, wherein the mass ratio of the polyacrylonitrile to the polyaniline is 1:1, and stirring for 24 hours to obtain catalyst slurry with the viscosity of 80 cp. Preparing a catalyst layer by adopting an electrostatic spinning technology, wherein the environmental parameters of electrostatic spinning are that the temperature is 25 ℃, and the relative humidity is 25% RH; the control parameters are as follows: the slurry feed rate was 0.5mL/h, the voltage was 15kV, the rotational speed of the drum receiver was 200rpm/min, the diameter of the needle was 20G, and the distance from the needle to the receiver was 10 cm. The Pt loading amount is 0.08mg cm by controlling the spinning time^-2The catalytic layer (2) has a thickness of about 1 μm. The temperature of the prepared catalyst layer after heat treatment is 200 ℃, the treatment time is 30min, and the treatment atmosphere is air, so that the high molecular polymer in the catalyst layer is vitrified. Finally, the catalytic layer is transferred to

211, hot-pressing at 135 deg.C under 0.2-0.5MPa for 100-300s, and preparing single-side membrane electrode. The anode was evaluated for electrochemical performance on a single cell evaluation apparatus using a commercial gas diffusion electrode. The battery operating conditions were: the temperature of the battery is 65 ℃; the gas wettability is 100%; h₂Flow 125mL min^-1(ii) a Air flow 800mL min^-1Cell back pressure 0.5bar, resulting in a full cell performance diagram as shown in fig. 13. This example showsPolyacrylonitrile and polyaniline used as catalyst slurry binders can also be prepared by an electrostatic spinning method, and full cell tests show that the maximum power density of the electrode in the embodiment is 555mW cm^-2。

Example 8

0.15g of 40 wt% Pt/C catalyst and 1.2g of 5 wt% Nafion solution are weighed, 0.12g of water and 0.4g of isopropanol are added, ultrasonic mixing is carried out, 0.04g of polyvinyl alcohol and hydroxypropyl cellulose high molecular polymer are added, and the mass ratio of the polyvinyl alcohol to the hydroxypropyl cellulose is 1: 1. Stirring for 36h gave a catalyst slurry with a viscosity of 100 cp. Preparing a catalyst layer by adopting an electrostatic spinning technology, wherein the environmental parameters of the electrostatic spinning are that the temperature is 25 ℃, and the relative humidity is 10% RH; the control parameters are as follows: the slurry feed rate was 1.2mL/h, the voltage was 20kV, the rotational speed of the drum receiver was 200rpm/min, the needle diameter was 15G, and the distance from the needle to the receiver was 12 cm. The Pt loading amount is 0.2mg cm by controlling the spinning time^-2The catalytic layer of (2), the catalytic layer having a thickness of about 4 μm. The temperature of the prepared catalyst layer after heat treatment is 180 ℃, the treatment time is 250min, and the treatment atmosphere is air, so that the high molecular polymer in the catalyst layer is vitrified. Finally, the catalytic layer is transferred to

211, hot-pressing at 140 deg.C under 0.2-0.5MPa for 120-240s, and preparing single-side membrane electrode. The anode was evaluated for electrochemical performance on a single cell evaluation apparatus using a commercial gas diffusion electrode. The battery operating conditions were: the temperature of the battery is 65 ℃; the gas wettability is 100%; h₂Flow 125mL min^-1(ii) a Air flow 800mL min^-1Cell back pressure 0.5bar, resulting in a full cell performance graph as shown in fig. 14. This example shows that polyvinyl alcohol and hydroxypropyl cellulose as catalyst slurry binders can also be prepared by electrospinning, and full cell testing shows that the maximum power density of the electrode prepared in this example is 518mW cm^-2。

Example 9

0.15g of 40 wt% Pt/C catalyst, 1.2g of 5 wt.% Nafion solution, 0.12g of water and 0.3g of isopropyl alcohol were weighed out and mixedAnd uniformly mixing the propanol by ultrasonic, and adding 0.025g of polyacrylic acid and polyvinylidene fluoride high-molecular polymer, wherein the mass ratio of the polyacrylic acid to the polyvinylidene fluoride is 1: 1. Stirring for 36h gave a catalyst slurry with a viscosity of 100 cp. Preparing a catalyst layer by adopting an electrostatic spinning technology, wherein the environmental parameters of the electrostatic spinning are that the temperature is 25 ℃, and the relative humidity is 10% RH; the control parameters are as follows: the slurry feed rate was 1.2mL/h, the voltage was 20kV, the rotational speed of the drum receiver was 200rpm/min, the needle diameter was 15G, and the distance from the needle to the receiver was 12 cm. The Pt loading amount is 0.2mg cm by controlling the spinning time^-2The catalytic layer of (2), the catalytic layer having a thickness of about 4 μm. The temperature of the prepared catalyst layer is 170 ℃ through heat treatment, the treatment time is 180min, and the treatment atmosphere is air, so that the high molecular polymer in the catalyst layer is vitrified. Finally, the catalytic layer is transferred to

211, hot-pressing at 140 deg.C under 0.2-0.5MPa for 120-240s, and preparing single-side membrane electrode. The anode was evaluated for electrochemical performance on a single cell evaluation apparatus using a commercial gas diffusion electrode. The battery operating conditions were: the temperature of the battery is 65 ℃; the gas wettability is 100%; h₂Flow 125mL min^-1(ii) a Air flow 800mL min^-1The cell back pressure was 0.5bar, and a full cell performance graph was obtained as shown in fig. 15. The example shows that polyacrylic acid and polyvinylidene fluoride as the catalyst slurry binder can be prepared by the electrostatic spinning method, and the full cell test shows that the maximum power density of the electrode prepared by the example is 509mW cm^-2。

Example 10

Weighing 0.1g of 40 wt.% Pt/C catalyst and 0.8g of 5 wt.% Nafion solution, adding 0.08g of water and 0.3g of isopropanol, ultrasonically mixing uniformly, then adding 0.02g of polyacrylic acid and polyethylene oxide high molecular polymer, wherein the mass ratio of the polyacrylic acid to the polyethylene oxide is 1:1, stirring for 36h to obtain a catalyst slurry with a viscosity of 100 cp. Preparing a catalyst layer by adopting an electrostatic spinning technology, wherein the environmental parameters of electrostatic spinning are that the temperature is 15 ℃, and the relative humidity is 30% RH; the control parameters are as follows: the slurry feed rate was 0.8mL/h and the voltage was 12kV, the rotating speed of the rotary drum receiver is 120rpm/min, the diameter of the needle is 22G, and the distance between the needle and the receiver is 12 cm. The Pt loading amount is 0.1mg cm by controlling the spinning time^-2The catalytic layer of (2) has a thickness of about 2 μm. The temperature of the prepared catalyst layer after heat treatment is 160 ℃, the treatment time is 100min, and the treatment atmosphere is air, so that the high molecular polymer in the catalyst layer is complexed. Finally, the catalytic layer is transferred to

211, hot-pressing at 140 deg.C under 0.2-0.5MPa for 120-240s, and preparing single-side membrane electrode. The anode was evaluated for electrochemical performance on a single cell evaluation apparatus using a commercial gas diffusion electrode. The battery operating conditions were: the temperature of the battery is 65 ℃; the gas wettability is 100%; h₂Flow 125mL min^-1(ii) a Air flow 800mL min^-1Cell back pressure 0.5bar, resulting in a full cell performance graph as shown in fig. 16. This example shows that polyacrylic acid and polyethylene oxide as catalyst slurry binders can also be prepared by electrospinning, and full cell testing shows that the maximum power density of the electrode prepared in this example is 494mW cm^-2。

Claims

1. A preparation method of a nanofiber electrode of a proton exchange membrane fuel cell is characterized by comprising the following steps: the method comprises the following steps:

(1) ultrasonically dispersing a catalyst and a perfluorinated sulfonic acid resin (Nafion) solution in a solvent, then adding a high molecular polymer, and stirring for 12-48h to obtain catalyst slurry;

(3) treating the catalyst layer precursor at 80-200 ℃ for 30-300 min to obtain a catalyst layer;

2. The method for producing an electrode according to claim 1, wherein: and (3) the heating treatment atmosphere is one of air, nitrogen and argon.

3. The method for producing an electrode according to claim 1, wherein: the catalyst in the step (1) is one or two of Pt/C, PtPd/C, PtFe/C, PtCo/C, PtNi/C, PtCu/C; in the catalyst, the mass fraction of Pt is 10-70 wt.%; the mass fraction of the Nafion solution is 5-15 wt.%; the mass ratio of the catalyst to the perfluorinated sulfonic acid resin to the high molecular polymer in the Nafion solution is 50:25:25-68:23: 9; the viscosity of the catalyst slurry is 50-200 cp.

4. The method for producing an electrode according to claim 1, wherein: the ultrasonic dispersion time in the step (1) is 1-4 h; the mass ratio of the catalyst to the solvent in the step (1) is 1:2-5, and the solvent is a mixed solution of water and isopropanol; in the mixed solution, the mass ratio of water to isopropanol is 1: 3-10.

5. The method for producing an electrode according to claim 1, wherein: the high molecular polymer comprises one or at least two of polyacrylic acid (PAA), Cyclodextrin (CD), polyvinyl alcohol (PVA), polyethylene oxide (PEO), glutaraldehyde, polyvinylpyrrolidone (PVP), hydroxypropyl cellulose (HPC), Polyacrylonitrile (PAN), polyvinylidene fluoride (PVDF), Polytetrafluoroethylene (PTFE) and Polyaniline (PANI).

6. The method for producing an electrode according to claim 1, wherein: the environmental parameters of the electrostatic spinning in the step (2) are as follows: the temperature is 10-30 ℃, and the relative humidity is 10-50% RH; the control parameters are as follows: the feeding speed of the catalyst slurry is 0.3mL/h-1.2mL/h, the voltage is 8kV-20kV, the rotating speed of the rotary drum receiver is 100rpm/min-300rpm/min, the diameter of the needle is 10G-25G, and the distance between the needle and the receiver is 8cm-15 cm.

7. The method for producing an electrode according to claim 1, wherein: the thickness of the catalytic layer is 1-5 μm.

8. The nanofiber electrode of the proton exchange membrane fuel cell prepared by the preparation method of the electrode of any one of claims 1 to 7, is characterized in that: the catalyst layer of the nanofiber electrode is of a nanofiber structure; the diameter of the nanofiber is 200nm-800nm, and the porosity of a catalytic layer of the nanofiber electrode is 25% -75%.

9. The nanofiber electrode of claim 8, wherein the catalytic layer is: the catalyst is uniformly coated on the outer side of the nanofiber framework.

10. Use of the nanofiber electrode of the proton exchange membrane fuel cell according to claim 8 in a membrane electrode of a proton exchange membrane fuel cell.