Proton exchange membrane fuel cell integrated electrode and preparation method thereof

Abstract

The invention discloses a proton exchange membrane fuel cell integrated electrode and a preparation method thereof, and the preparation method comprises the following steps: S1, spinning solution preparation: uniformly mixing a polymer and a dispersant to form a support layer spinning solution; uniformly mixing a polymer, a conductive agent, a water repellent and a dispersing agent to form a microporous layer spinning solution; uniformly mixing a polymer, MOFs and a dispersing agent to form a catalyst layer spinning solution; s2, electrostatic spinning, wherein the three spinning solutions prepared in the step S1 are subjected to high-voltage electrostatic spinning according to the sequence of a supporting layer, a microporous layer and a catalyst layer, and a nanofiber membrane is obtained; and S3, heat treatment: carrying out pre-oxidation and carbonization treatment on the nanofiber membrane, and then washing and drying to obtain the proton exchange membrane fuel cell integrated electrode. According to the invention, water transmission and air mass transfer in a high-current density area of the fuel cell can be improved, and the cell performance is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of fuel cells and relates to an integrated electrode for a proton exchange membrane fuel cell and a preparation method thereof. Background Art

[0002] Proton exchange membrane fuel cells have many advantages, including cleanliness, high energy conversion efficiency, suitable operating temperature and high reliability. Therefore, they are used as energy conversion devices and have achieved rapid development. However, proton exchange membrane fuel cells also face many problems, and their technical bottlenecks are particularly prominent. In fuel cells, the gas diffusion layer (composed of a support layer and a microporous layer) and the catalyst layer are between the flow field and the membrane. Their main functions are to support, catalyze and collect current, and provide channels for the transmission of reaction gases and product water. The catalytic effect and drainage performance are particularly important, which affect the diffusion of reaction gases and the discharge of product water, thereby affecting the battery performance.

[0003] Therefore, it is necessary to develop electrode materials for proton exchange membrane fuel cells, and it is expected to improve the overall performance of proton exchange membrane fuel cells, which is of great significance to the development and application of proton exchange membrane fuel cell industrialization. For example, Chinese patent applications No. 200510047370.1 and 201310692107.2 all disperse the conductive material (carbon powder particles) into an organic solvent, then add PTFE emulsion to obtain a slurry forming a microporous layer, and then apply it to the surface of the support by spraying or brushing to form a microporous layer. The microporous layer prepared by this process is in a disordered state, which affects the gas transmission and liquid water discharge effect. Chinese patent application No. 201811049161.4 discloses a method for preparing a gas diffusion layer. The method utilizes an electrospinning process to weave a mixed liquid containing a conductive material and a hydrophobic agent onto a support to form a microporous layer. Compared with traditional brushing or spraying methods, this method has a better ordered microporous structure, which improves the gas transmission performance of the microporous layer to a certain extent. However, how to further improve the gas transmission and liquid water discharge performance of the microporous layer still needs to be continuously studied. Summary of the invention

[0004] In view of the above-mentioned defects existing in the prior art, the purpose of the present invention is to provide an integrated electrode for a proton exchange membrane fuel cell and a preparation method thereof, which utilizes electrospinning technology to directly spin a support layer, a microporous layer and a catalyst layer together, thereby helping to reduce the thickness of the catalyst layer and the loading amount of the catalyst and improve the dispersibility of the catalyst. The fibrous structure obtained by spinning has good uniformity and a rich and moderate pore structure, which is helpful to improve water transport and air mass transfer in the high current density region of the fuel cell and improve battery performance.

[0005] To achieve the above object, the present invention adopts the following technical solution:

[0006] A first aspect of the present invention provides a method for preparing an integrated electrode for a proton exchange membrane fuel cell, comprising the following steps:

[0007] S1, preparation of spinning solution, mixing polymer and dispersant evenly to form a support layer spinning solution; mixing polymer, conductive agent, hydrophobic agent and dispersant evenly to form a microporous layer spinning solution; mixing polymer, MOFs and dispersant evenly to form a catalyst layer spinning solution;

[0008] S2, electrospinning, performing high-voltage electrospinning on the three spinning solutions prepared in step S1 in the order of a support layer, a microporous layer, and a catalyst layer to obtain a nanofiber membrane;

[0009] S3, heat treatment, pre-oxidation and carbonization treatment of the nanofiber membrane, followed by washing and drying to obtain a proton exchange membrane fuel cell integrated electrode.

[0010] Preferably, in step S1:

[0011] The polymer is selected from one or more of polyacrylonitrile, polyvinyl pyrrolidone, polyaniline and polymethyl methacrylate; and / or

[0012] The dispersant is selected from one or more of dimethyl diamide, ethanol, chloroform and acetone; and / or

[0013] The conductive agent is selected from one or more of acetylene black, oxidized carbon black, carbon nanotubes, and graphene; and / or

[0014] The hydrophobic agent is selected from one or more of polytetrafluoroethylene, polyvinylidene fluoride, polysiloxane, and polychlorotrifluoroethylene; and / or

[0015] The MOFs are selected from one or two of ZIF-67 and ZIF-8.

[0016] Preferably, in step S1:

[0017] In the support layer spinning solution, the mass fraction of the polymer is 10 to 14%;

[0018] In the microporous layer spinning solution, the mass fraction of the polymer is 10-14%, the mass fraction of the conductive agent is 2-4%, and the mass fraction of the hydrophobic agent is 2-3%;

[0019] In the catalyst layer spinning solution, the mass fraction of the polymer is 10-14%, and the mass fraction of the MOFs is 2-4%.

[0020] Preferably, when the spinning solution is prepared in step S1, ultrasound or heating stirring is used during mixing.

[0021] Preferably, when mixing by heating and stirring, the temperature is 40 to 100° C. and the stirring time is 5 to 8 hours.

[0022] Preferably, in the high-voltage electrospinning process in step S2, the needle aperture used is 0.3-2.0 mm, the syringe capacity is 5-20 ml, the spinning solution flow rate is 0.2-5 ml / hour, the roller speed is 50-1000 rpm, the voltage between the needle and the roller is 8-30 kV, the distance between the needle and the nanofiber membrane collection plate on the roller is 10-30 cm, the spinning temperature is 20-50°C, and the spinning humidity is 20-70% RH.

[0023] Preferably, the high voltage electrospinning uses a single needle or multiple needles; and / or

[0024] The nanofiber membrane collecting plate on the rotating roller is one of aluminum foil, tin foil and aluminum oxide foil, and its thickness is 10 to 100 microns.

[0025] Preferably, in step S2, the thickness of the nanofiber membrane is 0.1 to 0.5 mm.

[0026] Preferably, in step S3:

[0027] During the pre-oxidation treatment, the pre-oxidation temperature is 200-300° C. and the holding time is 1-6 hours;

[0028] The carbonization treatment is carried out under an inert protective gas, the carbonization temperature is 600-1500° C., and the heat preservation time is 1-12 hours.

[0029] Preferably, the heating rate of the pre-oxidation treatment is 2 to 20°C / min, and the heating rate of the carbonization treatment is 2 to 25°C / min; and / or

[0030] The inert protective gas is nitrogen or argon, and the gas flow rate is 50-200 ml / min.

[0031] Preferably, in step S3:

[0032] The washing process adopts deionized water cleaning or ultrasonic cleaning; when ultrasonic cleaning is adopted, the ultrasonic time used is 5 to 60 minutes; and / or

[0033] The drying is carried out in a vacuum drying oven or a blast drying oven, the drying temperature is 60-100° C., and the heat preservation time is 6-48 hours.

[0034] Preferably, in step S3:

[0035] The thickness of the integrated electrode of the proton exchange membrane fuel cell is 0.1-0.3 mm; on the integrated electrode of the proton exchange membrane fuel cell, the thickness of the support layer is 0.1-0.2 mm, the thickness of the microporous layer is 0.05-0.1 mm, and the thickness of the catalyst layer is 0.05-0.1 mm.

[0036] The second aspect of the present invention provides a proton exchange membrane fuel cell integrated electrode prepared according to the preparation method of the proton exchange membrane fuel cell integrated electrode according to the first aspect of the present invention, wherein the permeability coefficient of the proton exchange membrane fuel cell integrated electrode is 1.02×10 -12 ~1.37×10 -12 m 2 .

[0037] The integrated electrode and preparation method of proton exchange membrane fuel cell provided by the present invention have the following beneficial effects:

[0038] 1. The present invention improves the uniform dispersion of the water-repellent agent and the conductive agent in the microporous layer, and the conductive property and air permeability of the microporous layer are significantly improved;

[0039] 2. The present invention improves the activity of the catalyst in the catalyst layer, thereby improving the overall performance of the fuel cell;

[0040] 3. The integrated electrode of the proton exchange membrane fuel cell of the present invention has a catalyst layer with excellent catalytic activity, which can achieve high catalytic activity at high current density; the hydrophobic agent and the conductive agent of the microporous layer can be more evenly distributed on the support, improving the hydrophobic property of the microporous layer, thereby improving the gas transmission and liquid water discharge performance of the microporous layer; the present invention combines the microporous layer with the catalyst layer, which not only reduces the internal resistance of the fuel cell structure, but also reduces the difficulty of assembling the fuel cell;

[0041] 4. The present invention has the characteristics of simple preparation method, good conductivity and good chemical stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0043] Figure 1 It is a schematic flow chart of the method for preparing the integrated electrode of the proton exchange membrane fuel cell of the present invention;

[0044] Figure 2 This is a SEM image of the integrated electrode of the proton exchange membrane fuel cell prepared in Example 1 of the present invention;

[0045] Figure 3This is a cell performance curve diagram of the proton exchange membrane fuel cell integrated electrode prepared in Example 1 of the present invention and the traditional gas diffusion layer. DETAILED DESCRIPTION

[0046] In order to better understand the above technical solution of the present invention, the technical solution of the present invention is further described below in conjunction with embodiments.

[0047] Combination Figure 1 As shown, a method for preparing an integrated electrode for a proton exchange membrane fuel cell of the present invention, wherein the integrated electrode for a proton exchange membrane fuel cell comprises a support layer, a microporous layer and a catalyst layer arranged in sequence, and is prepared by electrospinning technology, specifically comprising the following steps:

[0048] S1, preparation of spinning solution, mixing polymer and dispersant evenly to form a support layer spinning solution; mixing polymer, conductive agent, hydrophobic agent and dispersant evenly to form a microporous layer spinning solution; mixing polymer, MOFs and dispersant evenly to form a catalyst layer spinning solution;

[0049] Specifically, the polymer and dispersant are configured in proportion, and are evenly mixed by ultrasound or heating stirring to form a support layer spinning solution; in the support layer spinning solution, the mass fraction of the polymer is 10-14%. The polymer, conductive agent, hydrophobic agent and dispersant are configured in proportion, and are evenly mixed by ultrasound or heating stirring to form a microporous layer spinning solution; in the microporous layer spinning solution, the mass fraction of the polymer is 10-14%, the mass fraction of the conductive agent is 2-4%, and the mass fraction of the hydrophobic agent is 2-3%. The polymer, MOFs and dispersant are configured in proportion, and are evenly mixed by ultrasound or heating stirring to form a catalyst layer spinning solution; in the catalyst layer spinning solution, the mass fraction of the polymer is 10-14%, and the mass fraction of MOFs is 2-4%.

[0050] Among them, among the materials used above, the polymer is selected from one or more of polyacrylonitrile, polyvinyl pyrrolidone, polyaniline, and polymethyl methacrylate; the dispersant is selected from one or more of dimethyl diamide, ethanol, chloroform, and acetone; the conductive agent is selected from one or more of acetylene black, oxidized carbon black, carbon nanotubes, and graphene; the hydrophobic agent is selected from one or more of polytetrafluoroethylene, polyvinylidene fluoride, polysiloxane, and polychlorotrifluoroethylene; and the MOFs are selected from one or two of ZIF-67 and ZIF-8.

[0051] When the spinning solution is prepared, the temperature is 40 to 100° C. and the stirring time is 5 to 8 hours when the mixing is carried out by heating and stirring (for example, heating in a water bath).

[0052] S2, electrospinning, performing high-voltage electrospinning on the three spinning solutions prepared in step S1 in the order of a support layer, a microporous layer, and a catalyst layer to obtain a nanofiber membrane;

[0053] Specifically, the support layer spinning solution, the microporous layer spinning solution, and the catalyst layer spinning solution are added to the syringe used for high-voltage electrospinning, and the spinning is carried out in the order of the support layer, the microporous layer, and the catalyst layer to obtain a nanofiber membrane with a thickness of 0.1 to 0.5 mm. The parameters in the high-voltage electrospinning process are as follows: the needle aperture used is 0.3 to 2.0 mm, the syringe capacity is 5 to 20 ml, the spinning solution flow rate is 0.2 to 5 ml / hour, the rotation speed of the roller is 50 to 1000 rpm, the voltage between the needle and the roller is 8 to 30 kV, the distance between the needle and the nanofiber membrane collecting plate on the roller is 10 to 30 cm, the spinning temperature is 20 to 50°C, and the spinning humidity is 20 to 70% RH. In the high-voltage electrospinning process, a single needle or multiple needles can be used; the nanofiber membrane collecting plate on the roller is one of aluminum foil, tin foil, and aluminum oxide foil, and its thickness is 10 to 100 microns.

[0054] S3, pre-oxidizing and carbonizing the nanofiber membrane, and then washing and drying it to obtain an integrated electrode for a proton exchange membrane fuel cell.

[0055] Specifically, the nanofiber membrane is pre-oxidized and carbonized in an atmosphere furnace (such as a tubular furnace), the pre-oxidation treatment is carried out in an air atmosphere, the pre-oxidation temperature is 200-300°C, the heating rate is 2-20°C / min, and the insulation time is 1-6 hours. The carbonization treatment is carried out under an inert protective gas, the carbonization temperature is 600-1500°C, the heating rate is 2-25°C / min, and the insulation time is 1-12 hours; wherein, the inert protective gas is nitrogen or argon, and the gas flow rate is 50-200 ml / min.

[0056] The carbonized nanofiber membrane is washed and dried, wherein deionized water or ultrasonic cleaning is used for washing, wherein the ultrasonic cleaning time is 5 to 60 minutes; and the drying is carried out in a vacuum drying oven or a blast drying oven, the drying temperature is 60 to 100°C, and the heat preservation time is 6 to 48 hours. Finally, a proton exchange membrane fuel cell integrated electrode with a thickness of 0.1 to 0.3 mm is obtained.

[0057] The prepared proton exchange membrane fuel cell integrated electrode has a support layer thickness of 0.1 to 0.2 mm, a microporous layer thickness of 0.05 to 0.1 mm, and a catalyst layer thickness of 0.05 to 0.1 mm.

[0058] Combination Figure 2The SEM image of the integrated electrode of the proton exchange membrane fuel cell shows that the Fe-NC catalyst on the electrode is a network interconnected structure of a three-dimensional multi-level pore structure; the catalyst in the catalytic layer has a large specific surface area and abundant active sites, has a Fe / N dual-functional catalytic effect, exhibits excellent electrocatalytic activity, and effectively improves the electrochemical performance of the proton exchange membrane fuel cell; in addition, the hydrophobic agent and the conductive agent of the microporous layer can be more evenly distributed on the support, improving the hydrophobicity of the microporous layer, thereby improving the gas transmission and liquid water discharge performance of the microporous layer; the permeability coefficient of the integrated electrode of the proton exchange membrane fuel cell is 1.02×10 -12 ~1.37×10 -12 m 2 , which is higher than the traditional gas diffusion layer (0.94×10 -12 m 2 ), it can be seen that the proton exchange membrane fuel cell integrated electrode prepared by the present invention has better air permeability. In addition, the catalyst layer of the proton exchange membrane fuel cell integrated electrode has excellent catalytic activity and can achieve high catalytic activity at high current density; the proton exchange membrane fuel cell integrated electrode not only reduces the internal resistance of the fuel cell structure, but also reduces the difficulty of assembling the fuel cell.

[0059] The integrated electrode for proton exchange membrane fuel cell and the preparation method of the present invention are further introduced below with reference to specific examples.

[0060] Example 1

[0061] The method for preparing an integrated electrode for a proton exchange membrane fuel cell of this embodiment adopts the following steps:

[0062] (1) First, a certain amount of polyacrylonitrile was added to an appropriate amount of dimethylformamide under stirring conditions, and stirred for 5 hours at a water bath temperature of 60°C to obtain a support layer spinning solution; in the support layer spinning solution, the mass fraction of polyacrylonitrile was 10%. Then, polyacrylonitrile, acetylene black and polytetrafluoroethylene were added to dimethylformamide under stirring conditions, and stirred for 6 hours at a water bath temperature of 60°C to obtain a microporous layer spinning solution; in the microporous layer spinning solution, the mass fractions of polyacrylonitrile, acetylene black and polytetrafluoroethylene were 10%, 2% and 2%, respectively. Finally, polyacrylonitrile and Fe / Zn-ZIFs were added to dimethylformamide under stirring conditions, and stirred for 8 hours at a water bath temperature of 60°C to obtain a catalyst layer spinning solution; in the catalyst layer spinning solution, the mass fractions of polyacrylonitrile and Fe / Zn-ZIFs were 10% and 2%, respectively.

[0063] (2) adding the three spinning solutions obtained in step (1) into 10 ml syringes respectively, and obtaining nanofiber membranes by electrospinning technology in the order of spinning the support layer first, spinning the microporous layer second, and spinning the catalyst layer last, wherein the thickness of the nanofiber membranes is 0.3 mm; wherein the electrospinning process parameters are as follows: the needle aperture is 0.3 mm, the distance between the needle and the nanofiber membrane collecting plate on the roller is 10 cm, the spinning voltage between the needle and the roller is 15 kV, the nanofiber membrane collecting plate is 200 μm thick tin foil, the roller speed is 200 rpm, the spinning solution flow rate is 0.5 ml / h, the spinning temperature is 30°C, and the humidity is 30% RH;

[0064] (3) The nanofiber membrane obtained in step (2) is placed in a tubular furnace for pre-oxidation and carbonization. The pre-oxidation temperature is 250°C, the heating rate is 5°C / min, the insulation time is 2 hours, and the atmosphere is air; the carbonization temperature is 800°C, the heating rate is 10°C / min, the insulation time is 4 hours, the inert protective atmosphere is nitrogen, and the gas flow rate is 100 ml / min.

[0065] (4) The carbonized material obtained in step (3) is washed with deionized water, and then placed in a vacuum drying oven at 80° C. for 12 hours. After drying, a proton exchange membrane fuel cell integrated electrode with a thickness of 0.2 mm is obtained, and the proton exchange membrane fuel cell integrated electrode consists of a support layer, a microporous layer and a Fe-NC catalyst.

[0066] The proton exchange membrane fuel cell integrated electrode prepared in this example was used as the cathode to assemble a single cell, and the performance was evaluated with that of a single cell assembled with a gas diffusion layer prepared by a conventional method. The battery was tested using a fuel cell test system, with a battery operating temperature of 60°C, a hydrogen humidification temperature of 60°C, an oxygen humidification temperature of 60°C, a hydrogen and oxygen pressure of 0.05MPa (gauge pressure), and a battery working area of ​​5cm 2 . According to the battery performance test results ( Figure 3 ) shows that the proton exchange membrane fuel cell integrated electrode prepared in this embodiment shows better battery performance at both low current density and high current density. It can be seen that the proton exchange membrane fuel cell integrated electrode prepared in this embodiment has a smaller ohmic resistance and better water-gas mass transfer performance. The reason is that the distribution of the conductive agent and the hydrophobic agent in the microporous layer of the proton exchange membrane fuel cell integrated electrode prepared in this embodiment is more uniform, and has a certain catalytic effect with the catalyst in the catalyst layer. In addition, the prepared gas diffusion layer was tested by using an aperture tester (Autosorb-IQ-MP, Quanta Instruments, USA) 2 The flux test results show that the permeability coefficient of the proton exchange membrane fuel cell integrated electrode prepared in this example is 1.37×10 -12 m2 , which is higher than the traditional gas diffusion layer (0.94×10 -12 m 2 ), indicating that the proton exchange membrane fuel cell integrated electrode prepared in this embodiment has better air permeability.

[0067] Example 2

[0068] The method for preparing an integrated electrode for a proton exchange membrane fuel cell of this embodiment adopts the following steps:

[0069] (1) First, a certain amount of polyacrylonitrile was added to an appropriate amount of dimethylformamide under stirring conditions, and stirred for 5 hours at a water bath temperature of 60°C to obtain a support layer spinning solution; in the support layer spinning solution, the mass fraction of polyacrylonitrile was 12%. Then, polyacrylonitrile, acetylene black and polytetrafluoroethylene were added to dimethylformamide under stirring conditions, and stirred for 6 hours at a water bath temperature of 60°C to obtain a microporous layer spinning solution; in the microporous layer spinning solution, the mass fractions of polyacrylonitrile, acetylene black and polytetrafluoroethylene were 12%, 3% and 2%, respectively. Finally, polyacrylonitrile and Co-ZIFs were added to dimethylformamide under stirring conditions, and stirred for 8 hours at a water bath temperature of 60°C to obtain a catalyst layer spinning solution; in the catalyst layer spinning solution, the mass fractions of polyacrylonitrile and Co-ZIFs were 12% and 3%, respectively.

[0070] (2) adding the three spinning solutions obtained in step (1) into a 10 ml syringe respectively, and obtaining a nanofiber membrane by electrospinning technology in the order of spinning the support layer first, spinning the microporous layer second, and spinning the catalyst layer last, wherein the thickness of the nanofiber membrane is 0.4 mm; wherein the electrospinning process parameters are: the needle aperture is 0.3 mm, the distance between the needle and the nanofiber membrane collecting plate on the roller is 15 cm, the spinning voltage between the needle and the roller is 15 kV, the nanofiber membrane collecting plate is 200 μm thick tin foil, the roller speed is 200 rpm, the spinning solution flow rate is 0.8 ml / h, the spinning temperature is 30°C, and the humidity is 30% RH;

[0071] (3) The nanofiber membrane obtained in step (2) is placed in a tubular furnace for pre-oxidation and carbonization. The pre-oxidation temperature is 250°C, the heating rate is 2°C / min, the insulation time is 2 hours, and the atmosphere is air; the carbonization temperature is 600°C, the heating rate is 10°C / min, the insulation time is 3 hours, the inert protective atmosphere is nitrogen, and the gas flow rate is 100 ml / min.

[0072] (4) The carbonized material obtained in step (3) is washed with deionized water, and then placed in a vacuum drying oven at 80° C. for 12 hours. After drying, a proton exchange membrane fuel cell integrated electrode with a thickness of 0.3 mm is obtained, and the proton exchange membrane fuel cell integrated electrode consists of a support layer, a microporous layer and a Co-NC catalyst.

[0073] The permeability coefficient of the integrated electrode of the proton exchange membrane fuel cell prepared in this example is 1.16×10 -12 m 2 .

[0074] Example 3

[0075] The method for preparing an integrated electrode for a proton exchange membrane fuel cell of this embodiment adopts the following steps:

[0076] (1) First, a certain amount of polyacrylonitrile was added to an appropriate amount of dimethylformamide under stirring conditions, and stirred for 5 hours at a water bath temperature of 60°C to obtain a support layer spinning solution; in the support layer spinning solution, the mass fraction of polyacrylonitrile was 14%. Then, polyacrylonitrile, acetylene black and polytetrafluoroethylene were added to dimethylformamide under stirring conditions, and stirred for 6 hours at a water bath temperature of 60°C to obtain a microporous layer spinning solution; in the microporous layer spinning solution, the mass fractions of polyacrylonitrile, acetylene black and polytetrafluoroethylene were 14%, 2% and 2%, respectively. Finally, polyacrylonitrile and Fe / Co-ZIFs were added to dimethylformamide under stirring conditions, and stirred for 8 hours at a water bath temperature of 60°C to obtain a catalyst layer spinning solution; in the catalyst layer spinning solution, the mass fractions of polyacrylonitrile and Fe / Co-ZIFs were 12% and 3%, respectively.

[0077] (2) adding the three spinning solutions obtained in step (1) into a 10 ml syringe respectively, and obtaining a nanofiber membrane by electrospinning technology in the order of spinning the support layer first, spinning the microporous layer second, and spinning the catalyst layer last, wherein the thickness of the nanofiber membrane is 0.3 mm; wherein the electrospinning process parameters are: the needle aperture is 0.3 mm, the distance between the needle and the nanofiber membrane collecting plate on the roller is 15 cm, the spinning voltage between the needle and the roller is 20 kV, the collecting plate is 200 μm thick tin foil, the roller speed is 100 rpm, the spinning solution flow rate is 0.6 ml / h, the spinning temperature is 30°C, and the humidity is 40% RH;

[0078] (3) The nanofiber membrane obtained in step (2) is placed in a tubular furnace for pre-oxidation and carbonization. The pre-oxidation temperature is 280°C, the heating rate is 5°C / min, the insulation time is 2 hours, and the atmosphere is air; the carbonization temperature is 800°C, the heating rate is 5°C / min, the insulation time is 3 hours, the inert protective atmosphere is nitrogen, and the gas flow rate is 100 ml / min.

[0079] (4) The carbonized material obtained in step (3) is cleaned by ultrasonic cleaning (ultrasonic time is 30 to 60 minutes), and then placed in a vacuum drying oven at 80° C. for 12 hours. The material after drying has a thickness of 0.2 mm and is a proton exchange membrane fuel cell integrated electrode, which is composed of a support layer, a microporous layer and a Fe / Co-NC catalyst.

[0080] The permeability coefficient of the integrated electrode of the proton exchange membrane fuel cell prepared in this example is 1.31×10 -12 m 2 .

[0081] Example 4

[0082] The method for preparing an integrated electrode for a proton exchange membrane fuel cell of this embodiment adopts the following steps:

[0083] (1) First, a certain amount of polyacrylonitrile was added to an appropriate amount of dimethylformamide under stirring conditions, and stirred for 5 hours at a water bath temperature of 60°C to obtain a support layer spinning solution; in the support layer spinning solution, the mass fraction of polyacrylonitrile was 10%. Then, polyacrylonitrile, acetylene black and polytetrafluoroethylene were added to dimethylformamide under stirring conditions, and stirred for 6 hours at a water bath temperature of 60°C to obtain a microporous layer spinning solution; in the microporous layer spinning solution, the mass fractions of polyacrylonitrile, acetylene black and polytetrafluoroethylene were 12%, 4% and 3%, respectively. Finally, polyacrylonitrile and Fe / Zn-ZIFs were added to dimethylformamide under stirring conditions, and stirred for 8 hours at a water bath temperature of 60°C to obtain a catalyst layer spinning solution; in the catalyst layer spinning solution, the mass fractions of polyacrylonitrile and Fe / Zn-ZIFs were 14% and 4%, respectively.

[0084] (2) adding the three spinning solutions obtained in step (1) into a 10 ml syringe respectively, and obtaining a nanofiber membrane by electrospinning technology in the order of spinning the support layer first, spinning the microporous layer second, and spinning the catalyst layer last, wherein the thickness of the nanofiber membrane is 0.3 mm; wherein the electrospinning process parameters are: the needle aperture is 0.3 mm, the distance between the needle and the nanofiber membrane collecting plate on the roller is 15 cm, the spinning voltage between the needle and the roller is 18 kV, the collecting plate is 200 μm thick tin foil, the roller speed is 300 rpm, the spinning solution flow rate is 0.5 ml / h, the spinning temperature is 30°C, and the humidity is 30% RH;

[0085] (3) The nanofiber membrane obtained in step (2) is placed in a tubular furnace for pre-oxidation and carbonization. The pre-oxidation temperature is 280°C, the heating rate is 3°C / min, the insulation time is 2 hours, and the atmosphere is air; the carbonization temperature is 800°C, the heating rate is 5°C / min, the insulation time is 4 hours, the inert protective atmosphere is nitrogen, and the gas flow rate is 100 ml / min.

[0086] (4) The carbonized material obtained in step (3) is cleaned by ultrasonic cleaning (ultrasonic time is 30 to 60 minutes), and then placed in a vacuum drying oven at 80° C. for 12 hours. The material after drying has a thickness of 0.2 mm and is a proton exchange membrane fuel cell integrated electrode, which is composed of a support layer, a microporous layer and a Fe-NC catalyst.

[0087] The permeability coefficient of the integrated electrode of the proton exchange membrane fuel cell prepared in this example is 1.27×10 -12 m 2 .

[0088] Example 5

[0089] The method for preparing an integrated electrode for a proton exchange membrane fuel cell of this embodiment adopts the following steps:

[0090] (1) First, a certain amount of polyacrylonitrile was added to an appropriate amount of dimethylformamide under stirring conditions, and stirred for 5 hours at a water bath temperature of 60°C to obtain a support layer spinning solution; in the support layer spinning solution, the mass fraction of polyacrylonitrile was 12%. Then, polyacrylonitrile, acetylene black and polytetrafluoroethylene were added to dimethylformamide under stirring conditions, and stirred for 6 hours at a water bath temperature of 60°C to obtain a microporous layer spinning solution; in the microporous layer spinning solution, the mass fractions of polyacrylonitrile, acetylene black and polytetrafluoroethylene were 10%, 3% and 3%, respectively. Finally, polyacrylonitrile and Fe / Zn-ZIFs were added to dimethylformamide under stirring conditions, and stirred for 8 hours at a water bath temperature of 60°C to obtain a catalyst layer spinning solution; in the catalyst layer spinning solution, the mass fractions of polyacrylonitrile and Fe / Zn-ZIFs were 14% and 2%, respectively.

[0091] (2) adding the three spinning solutions obtained in step (1) into a 10 ml syringe respectively, and obtaining a nanofiber membrane by electrospinning technology in the order of spinning the support layer first, spinning the microporous layer second, and spinning the catalyst layer last, wherein the thickness of the nanofiber membrane is 0.2 mm; wherein the electrospinning process parameters are: the needle aperture is 0.3 mm, the distance between the needle and the nanofiber membrane collecting plate on the roller is 15 cm, the spinning voltage between the needle and the roller is 20 kV, the collecting plate is 200 μm thick tin foil, the roller speed is 500 rpm, the spinning solution flow rate is 0.8 ml / h, the spinning temperature is 30°C, and the humidity is 30% RH;

[0092] (3) The nanofiber membrane obtained in step (2) is placed in a tubular furnace for pre-oxidation and carbonization. The pre-oxidation temperature is 300°C, the heating rate is 5°C / min, the insulation time is 2 hours, and the atmosphere is air; the carbonization temperature is 600°C, the heating rate is 10°C / min, the insulation time is 3 hours, the inert protective atmosphere is nitrogen, and the gas flow rate is 100 ml / min.

[0093] (4) The carbonized material obtained in step (3) is washed with deionized water, and then placed in a vacuum drying oven at 80° C. for 12 hours. The dried material has a proton exchange membrane fuel cell integrated electrode with a thickness of 0.2 mm, and the proton exchange membrane fuel cell integrated electrode is composed of a support layer, a microporous layer and a Fe-NC catalyst.

[0094] The permeability coefficient of the integrated electrode of the proton exchange membrane fuel cell prepared in this example is 1.12×10 -12 m 2 .

[0095] Example 6

[0096] The method for preparing an integrated electrode for a proton exchange membrane fuel cell of this embodiment adopts the following steps:

[0097] (1) First, a certain amount of polyacrylonitrile was added to an appropriate amount of dimethylformamide under stirring conditions, and stirred for 5 hours at a water bath temperature of 60°C to obtain a support layer spinning solution; in the support layer spinning solution, the mass fraction of polyacrylonitrile was 12%. Then, polyacrylonitrile, acetylene black and polytetrafluoroethylene were added to dimethylformamide under stirring conditions, and stirred for 6 hours at a water bath temperature of 60°C to obtain a microporous layer spinning solution; in the microporous layer spinning solution, the mass fractions of polyacrylonitrile, acetylene black and polytetrafluoroethylene were 12%, 4% and 2%, respectively. Finally, polyacrylonitrile and Co-ZIFs were added to dimethylformamide under stirring conditions, and stirred for 8 hours at a water bath temperature of 60°C to obtain a catalyst layer spinning solution; in the catalyst layer spinning solution, the mass fractions of polyacrylonitrile and Co-ZIFs were 12% and 4%, respectively.

[0098] (2) adding the three spinning solutions obtained in step (1) into a 10 ml syringe respectively, and obtaining a nanofiber membrane by electrospinning technology in the order of spinning the support layer first, then the microporous layer, and finally the catalyst layer, wherein the thickness of the nanofiber membrane is 0.4 mm; wherein the electrospinning process parameters are: the needle aperture is 0.5 mm, the distance between the needle and the nanofiber membrane collecting plate on the roller is 10 cm, the spinning voltage between the needle and the roller is 15 kV, the collecting plate is 200 μm thick tin foil, the roller speed is 600 rpm, the spinning solution flow rate is 1 ml / h, the spinning temperature is 30°C, and the humidity is 30% RH;

[0099] (3) The nanofiber membrane obtained in step (2) is placed in a tubular furnace for pre-oxidation and carbonization. The pre-oxidation temperature is 280°C, the heating rate is 5°C / min, the insulation time is 2 hours, and the atmosphere is air; the carbonization temperature is 800°C, the heating rate is 5°C / min, the insulation time is 4 hours, the inert protective atmosphere is nitrogen, and the gas flow rate is 100 ml / min.

[0100] (4) The carbonized material obtained in step (3) is placed in a vacuum drying oven at 80° C. for 12 hours. The dried material has a proton exchange membrane fuel cell integrated electrode with a thickness of 0.3 mm, and the proton exchange membrane fuel cell integrated electrode is composed of a support layer, a microporous layer and a Co-NC catalyst.

[0101] The permeability coefficient of the integrated electrode of the proton exchange membrane fuel cell prepared in this example is 1.13×10 -12 m 2 .

[0102] Example 7

[0103] The method for preparing an integrated electrode for a proton exchange membrane fuel cell of this embodiment adopts the following steps:

[0104] (1) First, a certain amount of polyacrylonitrile was added to an appropriate amount of dimethylformamide under stirring conditions, and stirred for 5 hours at a water bath temperature of 60°C to obtain a support layer spinning solution; in the support layer spinning solution, the mass fraction of polyacrylonitrile was 14%. Then, polyacrylonitrile, acetylene black and polytetrafluoroethylene were added to dimethylformamide under stirring conditions, and stirred for 6 hours at a water bath temperature of 60°C to obtain a microporous layer spinning solution; in the microporous layer spinning solution, the mass fractions of polyacrylonitrile, acetylene black and polytetrafluoroethylene were 10%, 3% and 3%, respectively. Finally, polyacrylonitrile and Fe / Co-ZIFs were added to dimethylformamide under stirring conditions, and stirred for 8 hours at a water bath temperature of 60°C to obtain a catalyst layer spinning solution; in the catalyst layer spinning solution, the mass fractions of polyacrylonitrile and Fe / Co-ZIFs were 10% and 3%, respectively.

[0105] (2) adding the three spinning solutions obtained in step (1) into a 10 ml syringe respectively, and obtaining a nanofiber membrane by electrospinning technology in the order of spinning the support layer first, then the microporous layer, and finally the catalyst layer, wherein the thickness of the nanofiber membrane is 0.3 mm; wherein the electrospinning process parameters are: the needle aperture is 0.5 mm, the distance between the needle and the nanofiber membrane collecting plate on the roller is 15 cm, the spinning voltage between the needle and the roller is 18 kV, the collecting plate is 200 μm thick tin foil, the roller speed is 600 rpm, the spinning solution flow rate is 0.5 ml / h, the spinning temperature is 30°C, and the humidity is 40% RH;

[0106] (3) The nanofiber membrane obtained in step (2) is placed in a tubular furnace for pre-oxidation and carbonization. The pre-oxidation temperature is 250°C, the heating rate is 2°C / min, the insulation time is 2 hours, and the atmosphere is air; the carbonization temperature is 800°C, the heating rate is 5°C / min, the insulation time is 3 hours, the inert protective atmosphere is nitrogen, and the gas flow rate is 100 ml / min.

[0107] (4) The carbonized material obtained in step (3) is placed in a vacuum drying oven at 80° C. for 12 hours. The dried material has a proton exchange membrane fuel cell integrated electrode thickness of 0.2 mm, and the proton exchange membrane fuel cell integrated electrode is composed of a support layer, a microporous layer and a Fe / Co-NC catalyst layer.

[0108] The permeability coefficient of the integrated electrode of the proton exchange membrane fuel cell prepared in this example is 1.02×10 -12 m 2 .

[0109] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present invention, and are not intended to limit the present invention. As long as they are within the spirit of the present invention, any changes or modifications to the above embodiments will fall within the scope of the claims of the present invention.

Claims

1. A method for preparing an integrated electrode for a proton exchange membrane fuel cell, characterized in that: The following steps are involved: S1, preparation of spinning solution, mixing polymer and dispersant evenly to form a support layer spinning solution; mixing polymer, conductive agent, hydrophobic agent and dispersant evenly to form a microporous layer spinning solution; mixing polymer, MOFs and dispersant evenly to form a catalyst layer spinning solution; S2, electrospinning, performing high-voltage electrospinning on the three spinning solutions prepared in step S1 in the order of a support layer, a microporous layer, and a catalyst layer to obtain a nanofiber membrane; S3, heat treatment, pre-oxidation and carbonization treatment of the nanofiber membrane, followed by washing and drying to obtain a proton exchange membrane fuel cell integrated electrode.

2. The method for preparing an integrated electrode for a proton exchange membrane fuel cell according to claim 1, characterized in that: In step S1: The polymer is selected from one or more of polyacrylonitrile, polyvinyl pyrrolidone, polyaniline and polymethyl methacrylate; and / or The dispersant is selected from one or more of dimethyl diamide, ethanol, chloroform and acetone; and / or The conductive agent is selected from one or more of acetylene black, oxidized carbon black, carbon nanotubes, and graphene; and / or The hydrophobic agent is selected from one or more of polytetrafluoroethylene, polyvinylidene fluoride, polysiloxane, and polychlorotrifluoroethylene; and / or The MOFs are selected from one or two of ZIF-67 and ZIF-8.

3. The method for preparing an integrated electrode for a proton exchange membrane fuel cell according to claim 1, characterized in that: In step S1: In the support layer spinning solution, the mass fraction of the polymer is 10 to 14%; In the microporous layer spinning solution, the mass fraction of the polymer is 10-14%, the mass fraction of the conductive agent is 2-4%, and the mass fraction of the hydrophobic agent is 2-3%; In the catalyst layer spinning solution, the mass fraction of the polymer is 10-14%, and the mass fraction of the MOFs is 2-4%.

4. The method for preparing an integrated electrode for a proton exchange membrane fuel cell according to claim 1, characterized in that: When the spinning solution in step S1 is prepared, ultrasonic or heating stirring is used during mixing.

5. The method for preparing an integrated electrode for a proton exchange membrane fuel cell according to claim 4, characterized in that: When mixing by heating and stirring, the temperature is 40-100°C and the stirring time is 5-8h.

6. The method for preparing an integrated electrode for a proton exchange membrane fuel cell according to claim 1, characterized in that: During the high-voltage electrospinning process in step S2, the needle aperture used is 0.3-2.0 mm, the syringe capacity is 5-20 ml, the spinning solution flow rate is 0.2-5 ml / hour, the roller speed is 50-1000 rpm, the voltage between the needle and the roller is 8-30 kV, the distance between the needle and the nanofiber membrane collection plate on the roller is 10-30 cm, the spinning temperature is 20-50°C, and the spinning humidity is 20-70% RH.

7. The method for preparing an integrated electrode for a proton exchange membrane fuel cell according to claim 6, characterized in that: The high-voltage electrospinning uses a single needle or multiple needles; and / or The nanofiber membrane collecting plate on the rotating roller is one of aluminum foil, tin foil and aluminum oxide foil, and its thickness is 10 to 100 microns.

8. The method for preparing an integrated electrode for a proton exchange membrane fuel cell according to claim 1, characterized in that: In the step S2, the thickness of the nanofiber membrane is 0.1 to 0.5 mm.

9. The method for preparing an integrated electrode for a proton exchange membrane fuel cell according to claim 1, characterized in that: In step S3: During the pre-oxidation treatment, the pre-oxidation temperature is 200-300° C. and the holding time is 1-6 hours; The carbonization treatment is carried out under an inert protective gas, the carbonization temperature is 600-1500° C., and the heat preservation time is 1-12 hours.

10. The method for preparing an integrated electrode for a proton exchange membrane fuel cell according to claim 9, characterized in that: The heating rate of the pre-oxidation treatment is 2 to 20°C / min, and the heating rate of the carbonization treatment is 2 to 25°C / min; and / or The inert protective gas is nitrogen or argon, and the gas flow rate is 50-200 ml / min.

11. The method for preparing an integrated electrode for a proton exchange membrane fuel cell according to claim 1, characterized in that: In step S3: The washing process adopts deionized water cleaning or ultrasonic cleaning; when ultrasonic cleaning is adopted, the ultrasonic time used is 5 to 60 minutes; and / or The drying is carried out in a vacuum drying oven or a blast drying oven, the drying temperature is 60-100° C., and the heat preservation time is 6-48 hours.

12. The method for preparing an integrated electrode for a proton exchange membrane fuel cell according to claim 1, characterized in that: In step S3: The thickness of the integrated electrode of the proton exchange membrane fuel cell is 0.1-0.3 mm; on the integrated electrode of the proton exchange membrane fuel cell, the thickness of the support layer is 0.1-0.2 mm, the thickness of the microporous layer is 0.05-0.1 mm, and the thickness of the catalyst layer is 0.05-0.1 mm.

13. A proton exchange membrane fuel cell integrated electrode obtained according to the method for preparing a proton exchange membrane fuel cell integrated electrode according to any one of claims 1 to 12, characterized in that: The integrated electrode permeability coefficient of the proton exchange membrane fuel cell is 1.02×10 -12 ~1.37×10 -12 m 2 .

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