An integrated flexible catalytic electrode and its preparation method

Abstract

The present invention belongs to the technical field of catalytic materials, and particularly relates to an integrated flexible catalytic electrode and a preparation method thereof. First, multiple nickel-based alloy wires are twisted into nickel-based alloy strands, and then multiple strands of nickel-based alloy strands are knitted into a fiber mesh. The integrated flexible catalytic electrode woven with nickel-based alloy wires has an integrated structure, can improve the catalytic activity of the catalytic electrode without spraying active materials, has a simple preparation process, can avoid the shedding of the active material coating, can reduce the contact resistance between the membrane and the electrode plate and the catalytic electrode, greatly improves the overall performance of the electrolytic cell, and is conducive to popularization and marketization.

Description

Technical Field

[0001] The present invention belongs to the technical field of catalytic materials, and particularly relates to an integrated flexible catalytic electrode and a preparation method thereof. Background Art

[0002] Alkaline water electrolysis for hydrogen production and alkaline membrane water electrolysis for hydrogen production technologies are currently widely used in electrolytic water hydrogen production due to their advantages such as high energy conversion efficiency and no need for noble metal catalysts in the electrolytic cell. However, at present, the electrode activity of alkaline water electrolysis for hydrogen production and alkaline membrane water electrolysis for hydrogen production is still insufficient, resulting in a small electrolysis current.

[0003] Patent CN116695162A discloses a method for preparing a catalytic layer on the surface of an electrode mesh for alkaline water electrolysis for hydrogen production, including the following steps: S1, preparing powder raw materials by using a mechanical solidification alloy process; S2, using a plasma spraying device to prepare a porous and rough coating on the surface of a nickel wire braided mesh, a stainless steel braided mesh, a nickel stamping mesh, a stainless steel stamping mesh, etc.; S3, the coated electrode is subjected to erosion pore-forming treatment with an erosion pore-forming solution, and then washed with deionized water and dried to obtain a porous NiCo alloy-coated electrode. By spraying an active coating on the surface of the metal braided mesh / stamping mesh, the electrode activity is improved.

[0004] Due to the low catalytic activity of nickel and stainless steel materials, it is necessary to spray active materials on the braided mesh / stamping mesh, which is cumbersome to operate, and the active coating is prone to falling off, resulting in unstable catalytic performance of the electrode mesh. Summary of the Invention

[0005] Aiming at the defects and deficiencies existing in the prior art, on the first hand, the present invention provides a preparation method for an integrated flexible catalytic electrode; on the second hand, the present invention provides an integrated flexible catalytic electrode prepared by the above preparation method.

[0006] To achieve the above object, the present invention provides the following technical solutions.

[0007] On the first hand, the present invention provides a preparation method for an integrated flexible catalytic electrode, including the following steps:

[0008] Twisting: twisting multiple nickel-based alloy wires into nickel-based alloy strands;

[0009] Knitting: knitting multiple nickel-based alloy strands into a fiber mesh, that is, obtaining a catalytic electrode.

[0010] Preferably, the nickel-based alloy wire is one or both of a nickel-iron alloy wire and a nickel-molybdenum alloy wire.

[0011] Further preferably, the mass ratio of nickel to iron in the nickel-iron alloy wire is 2-10:1.

[0012] More preferably, the mass ratio of nickel to molybdenum in the nickel-molybdenum alloy wire is 2 to 10:1.

[0013] Preferably, the nickel-based alloy is doped with a metal element M, and the metal element M is one or more of cobalt, copper, chromium, manganese, and aluminum.

[0014] More preferably, the addition amount of the metal element M is less than 10% of the total metal mass.

[0015] Preferably, in step 1, the diameter of the nickel-based alloy wire is 0.1 to 50 μm.

[0016] Preferably, in step 1, one strand of the nickel-based alloy strand is 1 to 500 nickel-based alloy wires.

[0017] Preferably, in step 2, the fiber web is knitted from nickel-iron alloy strands and nickel-molybdenum alloy strands.

[0018] More preferably, in the fiber web, the mass ratio of iron to molybdenum is 0.2 to 5:1.

[0019] Preferably, the knitting process is any one of plain knitting, twill knitting, and satin knitting.

[0020] Preferably, it further includes step 3 of superposing and calcining and pressing the fiber webs in step 2 to make a multi-layer metal fiber web.

[0021] Preferably, in step 3, the number of layers of the superposed fiber webs is 2 to 5 layers.

[0022] Preferably, the calcination process can be a single-stage or multi-stage process.

[0023] More preferably, in single-stage calcination, the calcination temperature is 400 to 800 °C and the calcination time is 0.5 to 5 h.

[0024] More preferably, in multi-stage calcination, the first-stage calcination temperature is 200 to 400 °C, the calcination time is 0.5 to 2 h, the second-stage calcination temperature is 400 - 800 °C, and the calcination time is 2 to 4 h.

[0025] Preferably, the fiber web obtained in step 2 is immersed in an etching solution and dried.

[0026] Preferably, the etching solution is any one of sulfuric acid, potassium hydroxide, and sodium hydroxide.

[0027] More preferably, the concentration of the etching solution is 1 to 10 mol / L.

[0028] More preferably, the etching temperature is 15 to 80 °C and the etching time is 2 to 240 min.

[0029] In a second aspect, the present invention provides an integrated flexible catalytic electrode prepared by the above preparation method.

[0030] Compared with the prior art, one or more of the above technical solutions of the present invention can achieve at least one of the following beneficial effects:

[0031] (1) The preparation method provided by the present invention uses nickel-based alloy wires to braid the catalytic electrode. The prepared integrated flexible catalytic electrode has an integrated structure, and the catalytic activity of the catalytic electrode can be improved without spraying the active material. The preparation process is simple, and the shedding of the active material coating can be avoided, which is beneficial to promotion and marketization.

[0032] (2) The integrated flexible catalytic electrode prepared by the present invention has the characteristics of being soft, having strong toughness and not being easily broken. The integrated flexible catalytic electrode can be in close contact with the membrane material, and when used in an electrolytic cell, it can reduce the contact resistance between the electrode, the membrane material and the electrode plate, which is beneficial to improving the electrochemical performance of the electrolytic cell, reducing energy consumption at the same time, and enhancing the economic benefits of the electrolytic cell.

[0033] (3) Before braiding the fiber mesh, multiple nickel-based alloy wires are processed into a stranded wire, and then braided, which increases the surface area of the fiber mesh and improves the mechanical strength of the fiber mesh.

[0034] (4) The catalytic activity of the catalytic electrode can be further improved by optimizing the diameter of the nickel-based alloy wire, the ratio of alloying elements, the etching process, etc. Description of the Drawings

[0035] Figure 1 It is a physical diagram of the catalytic electrode prepared in Example 1 of the present invention;

[0036] Figure 2 It is a physical diagram of the catalytic electrode prepared in Example 2 of the present invention;

[0037] Figure 3 It is an SEM diagram of the catalytic electrode prepared in Example 3 of the present invention;

[0038] Figure 4 It is an SEM diagram of the catalytic electrode prepared in Example 5 of the present invention;

[0039] Figure 5 It is the HER activity curve of the catalytic electrodes prepared in Example 1 and Comparative Example 1 of the present invention;

[0040] Figure 6 It is the OER activity curve of the catalytic electrodes prepared in Example 1 and Comparative Example 1 of the present invention;

[0041] Figure 7 It is the full electrolytic cell performance test curve of the catalytic electrodes prepared in Example 1 and Comparative Example 1 of the present invention;

[0042] Figure 8 This is the performance test curve of the full electrolytic cell of the catalytic electrodes prepared in Example 1 and Example 7 of the present invention;

[0043] Figure 9 This is the complex plane diagram of the electrochemical impedance of the full electrolytic cell of the catalytic electrodes prepared in Example 1 and Comparative Example 1 of the present invention. Detailed implementation manners

[0044] The present invention provides the following specific technical solutions.

[0045] In the first aspect, the present invention provides a preparation method of an integrated flexible catalytic electrode, including the following steps:

[0046] Twisting wires, twisting multiple nickel-based alloy wires into nickel-based alloy strands;

[0047] Knitting, knitting multiple strands of nickel-based alloy strands into a fiber mesh, thus obtaining the catalytic electrode.

[0048] The catalytic electrodes provided in the prior art usually include a conductive substrate and an active coating, which are prepared by spraying an active material on the surface of a woven mesh / stamped mesh. However, as the working time goes by, the active coating may fall off, affecting the catalytic performance and stability of the battery. The inventors have found through research that using nickel-based alloy wires to weave an integrated flexible catalytic electrode can improve the catalytic activity and stability of the catalytic electrode without additional spraying of active materials. At the same time, the catalytic electrode provided by the present invention does not need to face the problem of the active coating falling off and has good stability.

[0049] The catalytic electrode prepared by the present invention is made of nickel-based alloy and does not need to be sprayed with an active coating. Compared with the two-layer structure of the catalytic electrode prepared in the prior art, the catalytic electrode prepared by the present invention has an integrated structure. First, the integrated design makes the resistance of the material lower and the surface area larger, which is beneficial to improving the catalytic activity. Second, when using the fiber mesh as the catalytic electrode, the fiber mesh can closely adhere to the membrane material and the electrode plate of the electrolytic cell, which is beneficial to improving the electrochemical performance of the battery, reducing the energy consumption of the electrolytic cell, and improving the economic benefits of the electrolytic cell. Third, the catalytic electrode itself has both the functions of support and current conduction and has catalytic ability, so the stability and catalytic performance can be further improved, and the manufacturing process is simpler and the production cost is lower.

[0050] Preferably, the nickel-based alloy wire is one or two of nickel-iron alloy wire and nickel-molybdenum alloy wire.

[0051] The inventors have found through research that doping with a small amount of iron elements can improve the hydrogen evolution performance of the catalyst, resulting in a significant increase in the OER performance of water electrolysis; doping with a small amount of molybdenum elements can improve the hydrogen evolution performance of the catalyst, resulting in a significant increase in the HER performance of water electrolysis.

[0052] Further preferably, the mass ratio of nickel to iron in the nickel-iron alloy wire is 2-10:1.

[0053] Further preferably, the mass ratio of nickel to molybdenum in the nickel-molybdenum alloy wire is 2-10:1.

[0054] Preferably, the nickel-based alloy is doped with a metal element M, and the metal element M is one or more of cobalt, copper, chromium, manganese, and aluminum; preferably, the addition amount of the third element is less than 10% of the total metal mass.

[0055] Further preferably, the addition amount of the metal element M is less than 10% of the total metal mass.

[0056] The inventors have found through research that doping a third element into the nickel-based alloy wire can improve its catalytic performance and stability. The inventors have further found that when the doped third element is one or more of cobalt, copper, chromium, manganese, aluminum, etc., and the addition amount is less than 10% of the total metal mass, the catalytic performance and stability of the nickel-based alloy can be further improved.

[0057] Preferably, in step 1, the diameter of the nickel-based alloy wire is 0.1-50 μm.

[0058] For those skilled in the art, the diameter of the nickel-based alloy wire can be selected according to actual needs. In the specific embodiments of the present invention, the diameter of the nickel-based alloy wire can be 0.1 μm, 25 μm, 30 μm, 40 μm, 50 μm.

[0059] Preferably, in step 1, one strand of the nickel-based alloy strand is 1-500 nickel-based alloy wires.

[0060] For those skilled in the art, the number of nickel-based alloy wires used in the nickel-based alloy strand can be selected according to actual needs. In the specific embodiments of the present invention, the number of nickel-based alloy wires used in the nickel-based alloy strand can be 1, 6, 30, 50, 125, 250, 300, etc.

[0061] Preferably, in step 2, the fiber mesh is knitted from nickel-iron alloy strands and nickel-molybdenum alloy strands.

[0062] The inventors have found through research that by using nickel-iron alloy strands and nickel-molybdenum alloy strands for weaving, the prepared catalytic electrode can be used as both an anode and a cathode, improving the practicality of the material.

[0063] Further preferably, in the fiber mesh, the mass ratio of iron to molybdenum is 0.2-5:1.

[0064] In practical applications, the mass ratio of iron in the nickel-iron alloy strand and molybdenum in the nickel-molybdenum alloy strand can be adjusted according to actual needs. The inventors further studied and found that when the mass ratio of iron in the nickel-iron alloy strand and molybdenum in the nickel-molybdenum alloy strand is 0.2 - 5:1, the catalytic effects of the finally prepared alloy fiber mesh on both the cathode and the anode are improved, the production cost and processes are saved, and the efficiency is enhanced.

[0065] Preferably, the knitting process is one or more of plain knitting, twill knitting, and satin knitting.

[0066] Preferably, it further includes step 3 of superposing and calcining and pressing the fiber meshes in step 2 to make a multi-layer metal fiber mesh.

[0067] The inventors found through research that the multi-layer metal fiber mesh can effectively increase the catalytic area, and several layers of metal meshes can cooperate to promote the improvement of the electrolytic water catalytic efficiency. At the same time, the mesh structure is beneficial to the diffusion of water and gas. In practical applications, the aperture size, knitting density, and knitting fiber components of the metal mesh can be adjusted according to requirements.

[0068] Preferably, in step 3, the number of superposed fiber meshes is 2 - 5 layers.

[0069] For those skilled in the art, the number of superposed fiber meshes can be selected according to actual needs, and a single-layer fiber mesh can also be used as an integrated flexible catalytic electrode. To improve the catalytic effect of the integrated flexible catalytic electrode, in the specific embodiments of the present invention, the number of superposed fiber meshes can be 2 layers, 3 layers, 4 layers, 5 layers, or a single-layer fiber mesh can also be selected as the catalytic electrode for use.

[0070] Preferably, the calcination process can be a single-stage or multi-stage process.

[0071] For those skilled in the art, the calcination process can be selected according to actual needs.

[0072] Further preferably, in single-stage calcination, the calcination temperature is 400 - 800 °C, and the calcination time is 0.5 - 5 h.

[0073] For those skilled in the art, the calcination temperature and calcination time can be selected according to actual conditions. In the specific embodiments of the present invention, the calcination temperature can be 400 °C, 600 °C, 800 °C; the calcination time can be 0.5 h, 3 h, 5 h.

[0074] Further preferably, in multi-stage calcination, the first-stage calcination temperature is 200 - 400 °C, the calcination time is 0.5 - 2 h, the second-stage calcination temperature is 400 - 800 °C, and the calcination time is 2 - 4 h.

[0075] For those skilled in the art, the calcination temperature and time during multi-stage calcination can be selected according to actual situations.

[0076] Preferably, the fiber web obtained in Step 2 is immersed in an etching solution and dried.

[0077] During the research of the invention, it was found that by surface-treating the fiber web with an etching solution, the surface area of the fiber web can be further increased, thereby improving its catalytic activity.

[0078] Preferably, the etching solution is any one of sulfuric acid, potassium hydroxide, and sodium hydroxide.

[0079] More preferably, the concentration of the etching solution is 1 - 10 mol / L.

[0080] For those skilled in the art, the concentration of the etching solution can be selected according to actual needs. In the specific embodiments of the present invention, the concentration of the etching solution can be 1 mol / L, 2 mol / L, 3 mol / L, 5 mol / L, 6 mol / L, 10 mol / L.

[0081] More preferably, the etching temperature is 15 - 80 °C, and the etching time is 2 - 240 min.

[0082] For those skilled in the art, the etching temperature and time can be selected according to actual needs. In the specific embodiments of the present invention, the etching temperature can be 15 °C, 50 °C, 60 °C, 70 °C, 80 °C; the etching time can be 2 min, 50 min, 120 min, 200 min, 240 min.

[0083] In a second aspect, the present invention provides an integrated flexible catalytic electrode prepared by the above preparation method.

[0084] To make the technical problems, technical solutions, and technical advantages to be solved by the present invention clearer, the following will be described in detail with specific examples, but the protection scope of the present invention is not limited to the following specific embodiments.

[0085] Unless otherwise defined, all professional terms used hereinafter have the same meaning as commonly understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the protection scope of the present invention.

[0086] Unless otherwise specifically stated, various raw materials, reagents, instruments, and equipment used in the present invention can be obtained through market purchase or can be prepared by existing methods.

[0087] Example 1:

[0088] A preparation method of an integrated flexible catalytic electrode includes the following steps:

[0089] Step 1: Melting the nickel-molybdenum alloy raw material into an alloy liquid with a mass ratio of nickel to molybdenum of 6:1, cooling, and preparing a nickel-molybdenum alloy ingot.

[0090] Step 2: Drawing the nickel-molybdenum alloy ingot through a wire drawing process to obtain a nickel-molybdenum alloy wire with a diameter of 25 μm.

[0091] Step 3: Twisting 250 nickel-molybdenum alloy wires into a nickel-molybdenum alloy strand through a twisting process.

[0092] Step 4: Weaving the nickel-molybdenum alloy strand using a plain weave process to obtain a nickel-molybdenum alloy fiber mesh.

[0093] Step 5: Placing the nickel-molybdenum alloy fiber mesh in a 5 mol / L sulfuric acid solution for etching for 120 min at an etching temperature of 50 °C to obtain an etched nickel-molybdenum alloy fiber mesh, which is the integrated flexible catalytic electrode.

[0094] Example 2:

[0095] A preparation method of an integrated flexible catalytic electrode, comprising the following steps:

[0096] Step 1: Melting the nickel-iron alloy raw material into an alloy liquid and doping with aluminum, where the mass ratio of nickel, iron, and aluminum is 2:1:0.1, cooling, and preparing a nickel-iron alloy ingot.

[0097] Step 2: Drawing the nickel-iron alloy ingot through a wire drawing process to obtain a nickel-iron alloy wire with a diameter of 0.1 μm.

[0098] Step 3: One nickel-iron alloy wire is one strand of nickel-molybdenum alloy strand.

[0099] Step 4: Weaving the nickel-iron alloy strand using a plain weave process to obtain a nickel-iron alloy fiber mesh.

[0100] Step 5: Placing the nickel-iron alloy fiber mesh in a 1 mol / L potassium hydroxide solution for etching for 2 min at an etching temperature of 15 °C to obtain an etched nickel-iron alloy fiber mesh.

[0101] Step 6: Stacking 2 layers of the etched nickel-iron alloy fiber mesh, calcining at 400 °C for 0.5 h, and pressing the edges of the 2 layers of the etched nickel-iron alloy fiber mesh to prepare the nickel-iron alloy integrated flexible catalytic electrode.

[0102] Example 3:

[0103] A preparation method of an integrated flexible catalytic electrode, comprising the following steps:

[0104] Step 1: Melt the nickel-molybdenum alloy raw material into an alloy liquid with a mass ratio of nickel to molybdenum of 10:1 to obtain a nickel-molybdenum alloy ingot; melt the nickel-iron alloy raw material into an alloy liquid with a mass ratio of nickel to iron of 10:1 to obtain a nickel-iron alloy ingot.

[0105] Step 2: Draw the nickel-molybdenum alloy ingot and the nickel-iron alloy ingot through a wire drawing process to obtain nickel-molybdenum alloy wires and nickel-iron alloy wires with a diameter of 50 μm.

[0106] Step 3: Twist 50 nickel-molybdenum alloy wires into a strand of nickel-molybdenum alloy strand wire through a twisting process, and twist 125 nickel-iron alloy wires into a strand of nickel-iron alloy strand wire through a twisting process.

[0107] Step 4: Use the nickel-molybdenum alloy strand wire as the warp and the nickel-iron alloy strand wire as the weft, and use a plain weaving process to weave to obtain a nickel-molybdenum-nickel-iron alloy fiber mesh.

[0108] Step 5: Stack 5 layers of nickel-molybdenum-nickel-iron alloy fiber mesh, calcine at 800 °C for 5 h, and press 5 layers of etched nickel-molybdenum-nickel-iron alloy fiber mesh to obtain a nickel-molybdenum-nickel-iron alloy integrated flexible catalytic electrode.

[0109] Example 4:

[0110] A preparation method of an integrated flexible catalytic electrode, comprising the following steps:

[0111] Step 1: Melt the nickel-molybdenum alloy raw material into an alloy liquid with a mass ratio of nickel to molybdenum of 2:1 to obtain a nickel-molybdenum alloy ingot; melt the nickel-iron alloy raw material into an alloy liquid with a mass ratio of nickel to iron of 2:1.

[0112] Step 2: Draw the nickel-molybdenum alloy ingot and the nickel-iron alloy ingot through a wire drawing process to obtain nickel-molybdenum alloy wires and nickel-iron alloy wires with a diameter of 25 μm.

[0113] Step 3: Twist 30 nickel-molybdenum alloy wires into a strand of nickel-molybdenum alloy strand wire through a twisting process, and twist 6 nickel-iron alloy wires into a strand of nickel-iron alloy strand wire through a twisting process.

[0114] Step 4: Use the nickel-molybdenum alloy strand wire as the warp and the nickel-iron alloy strand wire as the weft, and use a plain weaving process to weave to obtain a nickel-molybdenum-nickel-iron alloy fiber mesh.

[0115] Step 5: Place the nickel-molybdenum-nickel-iron alloy fiber mesh in a 2 mol / L sulfuric acid solution for etching for 120 min at an etching temperature of 50 °C to obtain an etched nickel-molybdenum-nickel-iron alloy fiber mesh.

[0116] Step 6, stack 3 layers of etched nickel molybdenum-nickel iron alloy fiber mesh, calcine at 300 °C for 1 h and then at 600 °C for 3 h, press 3 layers of etched nickel molybdenum-nickel iron alloy fiber mesh to obtain a nickel molybdenum-nickel iron alloy integrated flexible catalytic electrode.

[0117] Example 5:

[0118] A preparation method of an integrated flexible catalytic electrode includes the following steps:

[0119] Step 1, melt the nickel molybdenum alloy raw material into an alloy liquid with a mass ratio of nickel to molybdenum of 4:1 to obtain a nickel molybdenum alloy ingot; melt the nickel iron alloy raw material into an alloy liquid with a mass ratio of nickel to iron of 4:1 to obtain a nickel iron alloy ingot.

[0120] Step 2, draw the nickel molybdenum alloy ingot and the nickel iron alloy ingot through a wire drawing process to obtain nickel molybdenum alloy wires and nickel iron alloy wires with a diameter of 30 μm.

[0121] Step 3, twist 100 nickel molybdenum alloy wires into a strand of nickel molybdenum alloy wire through a twisting process, and twist 300 nickel iron alloy wires into a strand of nickel iron alloy wire through a twisting process.

[0122] Step 4, use the nickel molybdenum alloy wire strand as the warp and the nickel iron alloy wire strand as the weft, and weave using a plain weave process to obtain a nickel molybdenum-nickel iron alloy fiber mesh.

[0123] Step 5, place the nickel molybdenum-nickel iron alloy fiber mesh in a 3 mol / L sodium hydroxide solution and etch for 200 min at an etching temperature of 60 °C to obtain an etched nickel molybdenum-nickel iron alloy fiber mesh.

[0124] Step 6, stack 4 layers of etched nickel molybdenum-nickel iron alloy fiber mesh, calcine at 200 °C for 0.5 h and then at 400 °C for 2 h, press the edges of the 4 layers of etched nickel molybdenum-nickel iron alloy fiber mesh to obtain a nickel molybdenum-nickel iron alloy integrated flexible catalytic electrode.

[0125] Example 6:

[0126] A preparation method of an integrated flexible catalytic electrode includes the following steps:

[0127] Step 1, melt the nickel molybdenum alloy raw material into an alloy liquid with a mass ratio of nickel to molybdenum of 8:1 to obtain a nickel molybdenum alloy ingot; melt the nickel iron alloy raw material into an alloy liquid with a mass ratio of nickel to iron of 4:1 to obtain a nickel iron alloy ingot.

[0128] Step 2, draw the nickel molybdenum alloy ingot and the nickel iron alloy ingot through a wire drawing process to obtain nickel molybdenum alloy wires and nickel iron alloy wires with a diameter of 40 μm.

[0129] Step 3: Twist 100 nickel-molybdenum alloy wires into a nickel-molybdenum alloy strand through a twisting process, and twist 250 nickel-iron alloy wires into a nickel-iron alloy strand through a twisting process.

[0130] Step 4: Use the nickel-molybdenum alloy strand as the warp and the nickel-iron alloy strand as the weft, and weave using a plain weave process to obtain a nickel-molybdenum-nickel-iron alloy fiber mesh.

[0131] Step 5: Place the nickel-molybdenum-nickel-iron alloy fiber mesh in a 6 mol / L sodium hydroxide solution and etch for 50 min at an etching temperature of 70 °C to obtain a nickel-molybdenum-nickel-iron alloy integrated flexible catalytic electrode.

[0132] Example 7:

[0133] The difference from Example 1 is that in Step 1, the nickel-molybdenum alloy raw material is melted into an alloy liquid and doped with lanthanum, where the mass ratio of nickel, molybdenum, and lanthanum is 6:1:0.2.

[0134] Comparative Example 1:

[0135] A preparation method of a commercial catalytic electrode includes the following steps:

[0136] Step 1: Immerse a commercial nickel foam mesh with a thickness of 2 mm in a 5 mol / L sulfuric acid solution and etch for 120 min at an etching temperature of 50 °C to obtain an etched commercial nickel foam mesh;

[0137] Step 2: Uniformly spray Raney nickel catalyst on the etched commercial nickel foam mesh to obtain a commercial catalytic electrode.

[0138] Figure 1 This is a physical picture of the catalytic electrode prepared in Example 1 of the present invention; Figure 2 This is a physical picture of the catalytic electrode prepared in Example 2 of the present invention. From Figure 1 and Figure 2 It can be intuitively observed that the catalytic electrode prepared by the preparation method provided by the present invention is a flexible structure.

[0139] Figure 3 This is the SEM image of the catalytic electrode prepared in Example 3 of the present invention; Figure 4 This is the SEM image of the catalytic electrode prepared in Example 5 of the present invention; Comparing Figure 3 and Figure 4 It can be seen that the catalytic electrode treated with the etching solution has a larger specific surface area.

[0140] Test the catalytic activity of the catalytic electrodes prepared in Example 1 and Comparative Example 1. The test method is as follows:

[0141] Half - electrolytic cell test: The catalytic electrodes prepared in Example 1 and Comparative Example 1 were cut into 5×5 cm square meshes, fixed with platinum electrode clips, and tested in an alkaline electrolyte of 0.1 mol / L KOH. The counter electrode used was a carbon rod, and the reference electrode used was a saturated calomel electrode. Before the linear voltammetry scan test, the material was activated by 10 cycles of voltammetry scan first, and then the linear voltammetry scan test was carried out at a scan rate of 5 mV / s. The test results are shown in Figure 5 、 Figure 6 。

[0142] It can be seen from Figure 5 that the HER activity of the catalytic electrode prepared in Example 1 is higher than that of the catalytic electrode prepared in Comparative Example 1. It can be seen from Figure 6 that the OER activity of the catalytic electrode prepared in Example 1 is higher than that of the catalytic electrode prepared in Comparative Example 1.

[0143] Full - electrolytic cell tests were carried out on the catalytic electrodes prepared in Example 1, Example 7, and Comparative Example 1. The test method is as follows:

[0144] The electrolytic cell device consists of a nickel - plated stainless - steel bipolar plate with a reaction area of 25 cm 2 with a direct current channel, a synthetic membrane electrode composed of the catalytic electrodes prepared in Example 1, Example 7, and Comparative Example 1 and a commercial membrane, a polytetrafluoroethylene sealing gasket, and the electrolyte used was a 30% mass - fraction KOH solution for full - electrolytic cell testing.

[0145] Figure 7 shows the comparison of the electrolytic cell performance of the catalytic electrodes prepared in Example 1 and Comparative Example 1; the catalytic performance of the catalytic electrode prepared in Example 1 is higher than that of the catalytic electrode prepared in Comparative Example 1.

[0146] Figure 8 shows the comparison of the electrolytic cell performance of the catalytic electrodes prepared in Example 1 and Example 7. The current density of the catalytic electrode prepared in Example 7 at the same potential is higher than that of the catalytic electrode prepared in Example 1. It can be seen that after doping the third element into the catalytic electrode, its catalytic performance is further improved.

[0147] The resistance of the catalytic electrodes prepared in Example 1 and Comparative Example 1 was tested. The test method is as follows:

[0148] The test used the EIS alternating - current impedance method. At the open - circuit potential, by applying a small - amplitude sine - wave potential with an amplitude of 5 mV, the complex - plane impedance diagram of the electrode was measured at a frequency of 1 - 100000 Hz.

[0149] Figure 9 is the plane impedance diagram of the catalytic electrodes prepared in Example 1 and Comparative Example 1. It can be seen that the resistance of the catalytic electrode prepared in Example 1 is much smaller than that of the catalytic electrode prepared in Comparative Example 1.

[0150] The above-described embodiments are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope of the present invention, according to the technical solution and its concept of the present invention, making equivalent substitutions or changes should be covered by the protection scope of the present invention.

Claims

1. A method for preparing an integrated flexible catalytic electrode, characterized in that: The steps include: Step 1, twisting a plurality of nickel-based alloy wires into nickel-based alloy strands; the diameter of the nickel-based alloy wires is 0.1-40 μm; and one strand of the nickel-based alloy strands contains 30-500 nickel-based alloy wires; Step 2, knitting, knitting multiple strands of nickel-based alloy wire into a fiber mesh to obtain a catalytic electrode.

2. The method for preparing an integrated flexible catalytic electrode according to claim 1, characterized in that: The nickel-based alloy wire is one or both of nickel-iron alloy wire and nickel-molybdenum alloy wire; the mass ratio of nickel to iron in the nickel-iron alloy wire is 2-10:1; the mass ratio of nickel to molybdenum in the nickel-molybdenum alloy wire is 2-10:

1.

3. The method for preparing an integrated flexible catalytic electrode according to claim 1, characterized in that: The nickel-based alloy is doped with a metal element M, and the metal element M is one or more of cobalt, copper, chromium, manganese, and aluminum; the added amount of the metal element M is less than 10% of the total metal mass.

4. The method for preparing an integrated flexible catalytic electrode according to claim 2, characterized in that: In step 2, the fiber mesh is knitted with nickel-iron alloy strands and nickel-molybdenum alloy strands; in the fiber mesh, the mass ratio of iron to molybdenum is 0.2-5:

1.

5. The method for preparing an integrated flexible catalytic electrode according to any one of claims 1 to 4, characterized in that: In step 2, the knitting process is any one of plain weave, twill weave and satin weave.

6. The method for preparing an integrated flexible catalytic electrode according to claim 1, characterized in that: The method further comprises step 3 of stacking, calcining and pressing the fiber meshes in multiple layers in step 2 to form a multi-layer metal fiber mesh.

7. The method for preparing an integrated flexible catalytic electrode according to claim 6, characterized in that: In step 3, the number of superimposed fiber web layers is 2 to 5 layers; the calcination process can be a one-stage or multi-stage process; in the one-stage calcination, the calcination temperature is 400 to 800°C, and the calcination time is 0.5 to 5h; in the multi-stage calcination, the calcination temperature of the first stage is 200 to 400°C, the calcination time is 0.5 to 2h, and the calcination temperature of the second stage is 400 to 800°C, and the calcination time is 2 to 4h.

8. The method for preparing an integrated flexible catalytic electrode according to claim 1, characterized in that: The fiber web obtained in step 2 is immersed in an etching solution and dried; the etching solution is one or more of sulfuric acid, potassium hydroxide, and sodium hydroxide solution; the concentration of the etching solution is 1-10 mol / L.

9. An integrated flexible catalytic electrode, characterized in that: Prepared by the preparation method according to any one of claims 1 to 8.

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