Modified nickel-based electrode and preparation method and equipment thereof

Abstract

The invention belongs to the field of catalytic electrodes, and particularly discloses a modified nickel-based electrode and a preparation method thereof.The preparation method of the modified nickel-based electrode comprises the steps that 1, a nickel-based electrode is placed in a precursor solution to be soaked and then transferred into an inert atmosphere or a vacuum atmosphere to be roasted, and a primary modified electrode is obtained; and 2, the step 1 is repeated for one or more times, a secondary modified electrode or a multi-stage modified electrode can be prepared, and the precursor solution is any one or more than two of a sodium phosphite solution and a metal salt solution. A nickel-based electrode is treated through sodium phosphite, phosphide with heterojunction and electronic properties is formed on the surface of the nickel-based electrode, more active sites are provided, a metal salt solution is introduced to treat the sodium phosphite, new active components are introduced, and the performance of the catalytic electrode is regulated and controlled through metal deposition and alloying; and the synergistic effect between the introduced metal element and nickel interacts in the catalytic reaction, so that the catalytic activity and selectivity of the electrode are jointly improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of catalytic electrodes, and relates to a nickel-based catalytic electrode material, in particular to a modified nickel-based electrode and a preparation method thereof. BACKGROUND

[0002] With the surge in global demand for clean energy, electrocatalysis technology plays a key role in realizing efficient conversion and storage of renewable energy in the fields of water electrolysis for hydrogen production, carbon dioxide reduction, fuel cells, etc. The catalytic performance of electrode materials directly determines the reaction efficiency and energy consumption level. Although noble metal catalysts (such as platinum and iridium) have excellent activity, they are difficult to meet the demand of large-scale industrial application due to their scarcity and high cost. Under this background, nickel-based catalytic electrodes have become a potential non-noble metal catalyst material due to their abundant resources (about 0.8% of nickel content in the earth's crust), low price (about 1 / 50 of the price of platinum), adjustable electronic structure and good electrical conductivity, and have been widely studied in key electrocatalytic processes such as hydrogen evolution reaction (HER), oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). However, the current nickel-based catalytic electrode still faces multiple technical bottlenecks in practical application. The first problem is the lack of catalytic activity. Compared with noble metal catalysts, the intrinsic activity of nickel-based materials is lower, and a higher overpotential is required to drive the reaction. From the perspective of preparation process, the synthesis of high-performance nickel-based catalytic electrodes still has limitations. Although nanostructure or heterojunction design can improve catalytic activity, it relies on complex methods (such as template-assisted growth and atomic layer deposition), resulting in high cost and difficulty in mass production. The materials synthesized by simple preparation techniques (such as co-precipitation method) often have uneven distribution of active sites and ideal crystal face exposure, which affects their catalytic activity. Therefore, developing nickel-based catalytic electrode materials and technologies with high catalytic activity and low cost preparation, and breaking through the performance and cost bottlenecks of existing electrocatalytic systems, has become a core task to promote the large-scale application of clean energy technologies such as hydrogen production and carbon neutralization. SUMMARY

[0003] In view of the defects and deficiencies of the prior art, the application provides a modified nickel-based electrode, a preparation method and equipment thereof.

[0004] In a first aspect, the application provides a preparation method of a modified nickel-based electrode, comprising the following steps: Step 1: soaking the nickel-based electrode in a precursor solution, and then transferring it to an inert atmosphere or a vacuum atmosphere for calcination to obtain a first modified electrode; Step 2: repeating step 1 one or more times to obtain the modified nickel-based electrode; The precursor solution is any one or more than two of a sodium phosphite solution and a metal salt solution.

[0005] Preferably, the metal element in the metal M salt solution is any one or more than two of molybdenum, copper, silver, iron, manganese, chromium, nickel, cobalt, platinum and iridium; the metal M salt solution is any one or more than two of nitrate solution, chloride solution, sulfate solution, wherein, when the metal element M is molybdenum, the metal M salt is sodium molybdate.

[0006] Preferably, the nickel-based electrode is any one of nickel-based fiber cloth and flexible nickel mesh.

[0007] Preferably, in step 1, the soaking time is 30s-30min.

[0008] Preferably, in step 1, the calcination temperature is 100-500℃, and the calcination time is 10-60min.

[0009] Preferably, the gas for providing an inert atmosphere is any one or both of argon and nitrogen.

[0010] Preferably, a method for preparing a modified nickel-based electrode comprises the following steps: Step 1, soaking the nickel-based electrode in a precursor solution, and then transferring to an inert atmosphere or a vacuum atmosphere for calcination to obtain a primary modified electrode; Step 2, soaking the primary modified electrode in a precursor solution, and then transferring to an inert atmosphere or a vacuum atmosphere for calcination to obtain a modified nickel-based electrode; The precursor solution is a mixed solution of sodium phosphite solution and metal M salt solution.

[0011] Preferably, in steps 1 and 2, the calcination temperature is 200-500℃, and the calcination time is 0.1-1h.

[0012] Preferably, the concentration of sodium phosphite in the precursor solution is 1-3mol / L, and the concentration of M in the precursor solution is 10-50mmol / L.

[0013] Preferably, a method for preparing a modified nickel-based electrode comprises the following steps: Step 1, soaking the nickel-based electrode in a first precursor solution, and then transferring to an inert atmosphere or a vacuum atmosphere for calcination to obtain a primary modified electrode; Step 2, soaking the primary modified electrode in a second precursor solution again, and then transferring to an inert atmosphere or a vacuum atmosphere for calcination to obtain a secondary modified electrode; Step 3, soaking the secondary modified electrode in a third precursor solution, and then transferring to an inert atmosphere or a vacuum atmosphere for calcination to obtain a modified nickel-based electrode; The first precursor solution is a mixed solution of sodium phosphite solution and M1 metal salt solution, wherein M1 is any one or more than two of molybdenum, copper, iron, manganese, chromium, nickel and cobalt; The second precursor solution is a mixed solution of sodium phosphite solution and M2 metal salt solution, wherein M2 is any one or more than two of silver, platinum and iridium; The third precursor solution is any one or more than two of silver nitrate solution, chloroplatinic acid solution and chloroiridic acid solution.

[0014] Preferably, in steps 1-3, the temperature of the calcination is 200-500°C, and the time of the calcination is 0.1-1h.

[0015] Preferably, the concentration of sodium phosphite in the first precursor solution is 1-5mol / L, and the concentration of M1 in the first precursor solution is 0.1-100mmol / L.

[0016] Preferably, the concentration of sodium phosphite in the second precursor solution is 1-5mol / L, and the concentration of M2 in the second precursor solution is 0.01-100mmol / L.

[0017] Preferably, the concentration of the metal element in the third precursor solution is 0.01-100mmol / L.

[0018] Preferably, a method for preparing a modified nickel-based electrode comprises the following steps: Step 1: soaking a nickel-based electrode in a sodium phosphite solution, and then transferring to calcination under an inert atmosphere to obtain a primary modified electrode; Step 2: soaking the primary modified electrode in a precursor solution, and then transferring to calcination under an inert atmosphere to obtain a modified nickel-based electrode; The precursor solution is a mixed solution of sodium phosphite solution and M3 metal salt solution, wherein M3 is silver, molybdenum and copper.

[0019] Preferably, in steps 1 and 2, the temperature of the calcination is 200-500°C, and the time of the calcination is 10-60min.

[0020] Preferably, in step 1, the concentration of the sodium phosphite solution is 0.5-3.0mol / L.

[0021] Preferably, in step 2, the molar ratio of sodium phosphite, molybdenum ions, copper ions and silver ions in the mixed solution is 1:0.001-0.01:0.001-0.02:0.001-0.02; the concentration of sodium phosphite in the mixed solution is 2-3mol / L; and the sum of the concentrations of molybdenum ions, copper ions and silver ions in the mixed solution is 1-20mmol / L.

[0022] In a second aspect, the present application provides a modified nickel-based electrode prepared by the above method.

[0023] Preferably, the modified nickel-based electrode comprises a substrate and a first cladding layer, a second cladding layer, and an Nth cladding layer, wherein N is an integer; the substrate is a nickel-based material; the first cladding layer at least clads part of the surface of the substrate, the second cladding layer at least clads part of the surface of the material composed of the substrate and the first cladding layer; and the Nth cladding layer at least clads part of the surface of the material composed of the substrate, the first cladding layer, the second cladding layer, and so on to the (N-1)th cladding layer.

[0024] Further preferably, 0≤N≤5.

[0025] In a third aspect, the present application provides a device for continuous production of a modified nickel-based electrode, comprising a reel one, a reel two, and a plurality of modification devices arranged between the reel one and the reel two; the reel one is used for unwinding the nickel-based electrode, and the reel two is used for winding the nickel-based electrode; the plurality of modification devices are arranged in sequence along the moving direction of the nickel-based electrode, and each modification device comprises a soaking tank and a calcination furnace, and the soaking tank is arranged upstream of the calcination furnace.

[0026] Preferably, the device further comprises a plurality of redirection reels, and the redirection reels are rotationally arranged, and the plurality of redirection reels are arranged at intervals along the moving direction of the nickel-based electrode.

[0027] Preferably, the height positions of adjacent two redirection reels are different, so as to adjust the moving direction of the nickel-based electrode or support the nickel-based electrode.

[0028] Compared with the prior art, the one or more technical solutions provided by the present application at least have one of the following beneficial effects: (1) By treating the nickel-based electrode with sodium phosphite, phosphides with heterojunctions and electronic properties are formed on the surface of the nickel-based electrode, providing more active sites, thereby improving the catalytic activity of the nickel-based electrode; and the formation of phosphides can improve the chemical stability of the electrode surface, improve the corrosion resistance and oxidation resistance of the nickel-based electrode, and prolong the service life of the nickel-based electrode. By treating sodium phosphite with a metal salt solution, new active components are introduced, the performance of the catalytic electrode is regulated through metal deposition and alloying, and the synergistic effect between the introduced metal elements and nickel interacts in the catalytic reaction, thereby improving the catalytic activity and selectivity of the electrode.

[0029] (2) By using the mixed solution of sodium phosphite solution and metal salt solution to treat the nickel-based electrode, the generated phosphide can provide more active sites, and the introduced metal elements can adjust the adsorption and reaction process of the reactant molecules on the active sites, thereby improving the efficiency and selectivity of the reaction; there is a synergistic catalysis between the phosphide and the introduced metal elements, which further enhances the catalytic activity and selectivity of the electrode.

[0030] (3) The nickel-based electrode is first treated with a sodium phosphite solution, and then the first modified electrode is treated with a mixed solution of sodium phosphite and salt solution, the first coating layer material can cooperate with the nickel substrate and increase the active area; the second coating layer can form a heterostructure with the first coating layer; the first coating layer and the second coating layer cooperate to further improve the surface area and activity of the active sites of the nickel-based electrode.

[0031] (4) The nickel-based electrode modification method of the present application is easy to operate, and the preparation process is simple and convenient, which is conducive to marketization and commercialization. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 The structure schematic diagram of the equipment for continuous production of the modified nickel-based electrode provided by the present application is shown in the figure; Figure 2 The SEM image of the nickel-based fiber cloth used in Examples 2-14 and Comparative Examples 1-3 is shown in the figure; Figure 3 The SEM image of the modified nickel-based electrode prepared in Example 5 is shown in the figure; Figure 4 The SEM image of the modified nickel-based electrode prepared in Example 8 is shown in the figure; Figure 5 The test chart of the alkaline electrolytic cell using the nickel-based electrode prepared in Examples 2-4 and Comparative Examples 1-3 as a catalytic electrode is shown in the figure; Figure 6 The test chart of the alkaline electrolytic cell using the nickel-based electrode prepared in Examples 5-7 as a catalytic electrode is shown in the figure; Figure 7 The test chart of the alkaline electrolytic cell using the nickel-based electrode prepared in Examples 8-10 as a catalytic electrode is shown in the figure.

[0033] Label explanation: 1, reel one; 2, reel two; 3, modification device; 3.1, soaking pool; 3.2, calcination furnace; 4, redirection reel. DETAILED DESCRIPTION

[0034] The present application provides the following specific technical solutions.

[0035] In a first aspect, the present application provides a preparation method of a modified nickel-based electrode, comprising the following steps: Step 1, immerse the nickel-based electrode in the precursor solution, and then transfer to an inert atmosphere or a vacuum atmosphere for calcination to obtain a first modified electrode; Step 2, repeat step 1 one or more times to obtain the modified nickel-based electrode. The precursor solution is any one or more of a sodium phosphite solution and a metal salt solution.

[0036] The inventors have found that, when the nickel-based electrode is treated with a metal salt solution, the metal salt will decompose and crystallize during calcination to form ultra-fine nano-sized particles. In the presence of sodium phosphite, the ultra-fine particles fuse with the nickel surface to form a nickel and other metal bimetallic or multimetallic phosphide rivet on the surface of the nickel-based electrode, which can increase the specific surface area and activity of the electrode, and at the same time enhance the interfacial force between the ultra-fine particles and the nickel fibers, which is beneficial to improve the reaction activity of the electrode. Metal atoms can alloy with nickel atoms in the presence of sodium phosphite to form alloys with different compositions and structures, which can change the electronic structure and crystal structure of the electrode, thereby affecting the catalytic performance of the electrode. The introduced metal elements and nickel may have a synergistic effect, that is, they interact with each other in the catalytic reaction to improve the catalytic activity and selectivity of the electrode.

[0037] Repeating step 1 one or more times can increase the loading of active components. Each immersion-calcination process introduces active components (such as phosphorus elements and metal elements) to the surface of the nickel-based electrode in the precursor solution, and multiple repetitions of this step can gradually increase the loading of active components on the surface of the electrode, allowing the electrode surface to have more active sites and thus improving the catalytic activity and performance of the electrode. On the other hand, it can optimize the distribution of active components. Through multiple repetitions, the active components can be more evenly distributed on the surface of the nickel-based electrode. The first immersion-calcination may form a preliminary distribution of active components on the electrode surface, but there may be uneven distribution. Subsequent repeated operations can adjust and optimize this distribution, allowing the active components to better cover the electrode surface and improve the overall performance of the electrode.

[0038] Preferably, the metal element in the metal M salt solution is any one or more of molybdenum, copper, silver, iron, manganese, chromium, nickel, cobalt, platinum, and iridium; and the metal M salt solution is any one or more of a nitrate salt solution, a chloride salt solution, and a sulfate salt solution. When the metal element is molybdenum, the metal salt solution is sodium molybdate.

[0039] The inventors further found that the synergistic effect between the phosphide and the metal elements selected from molybdenum, copper, silver, iron, manganese, chromium, nickel, cobalt and platinum is further enhanced in the mixed treatment process, and the processes such as electron transfer, adsorption-desorption can cooperate with each other to promote the catalytic reaction, thereby achieving better catalytic effect than using sodium phosphite or metal salt solution alone.

[0040] Preferably, the nickel-based electrode is any one of a nickel-based fiber cloth and a flexible nickel mesh.

[0041] Preferably, in step 1, the soaking time is 30 s to 30 min.

[0042] Preferably, in step 1, the temperature of the calcination is 100-500℃, and the time of the calcination is 10-60 min.

[0043] In actual application, the temperature of the calcination can be 100℃, 200℃, 300℃, 400℃, 500℃; and the time of the calcination can be 10 min, 20 min, 30 min, 40 min, 50 min, 60 min.

[0044] Preferably, the gas providing the inert atmosphere is any one or both of argon and nitrogen.

[0045] In some embodiments of the present application, the preparation method of the modified nickel-based electrode is specifically as follows: Step 1: soaking the nickel-based electrode in a precursor solution, and then transferring to an inert atmosphere or a vacuum atmosphere for calcination to obtain a first modified electrode; Step 2: soaking the first modified electrode in a precursor solution, and then transferring to an inert atmosphere or a vacuum atmosphere for calcination to obtain a modified nickel-based electrode; The precursor solution is a mixed solution of a sodium phosphite solution and a metal M salt solution.

[0046] The inventors found that the components in the sodium phosphite and metal salt solution interact with each other to jointly affect the structure and performance of the electrode surface. The formation of phosphide and the introduction of metal elements will affect each other, forming a complex surface structure and electronic environment. The metal elements can affect the formation process and crystal structure of the phosphide, while the phosphide can affect the dispersion and existence state of the metal elements. The synergistic effect between the phosphide and the introduced metal elements can be enhanced in the mixed treatment process, and the processes such as electron transfer, adsorption-desorption can cooperate with each other to promote the catalytic reaction, thereby achieving better catalytic effect than using sodium phosphite or metal salt solution alone.

[0047] The metal ions in the metal salt solution are reduced to metal atoms in the process of calcination, and the metal atoms react with the nickel atoms in the nickel-based electrode and the phosphorus element generated by the decomposition of sodium hypophosphite to form alloys or intermetallic compounds. The alloys or intermetallic compounds have a more compact atomic arrangement and stronger chemical bonds than single metals, which can enhance the bonding force between the active layer and the substrate. These chemical bonds (such as metal-metal bonds and metal-phosphorus bonds) have high bond energy, which makes the active layer firmly adhere to the surface of the nickel-based electrode.

[0048] Preferably, in steps 1 and 2, the calcination temperature is 200-500℃, and the calcination time is 0.1-1h.

[0049] Preferably, the concentration of sodium hypophosphite in the precursor solution is 1-3mol / L, and the concentration of metal ions in the precursor solution is 10-50mmol / L.

[0050] In some embodiments of the present application, the preparation method of the modified nickel-based electrode is as follows: Step 1: Soak the nickel-based electrode in a first precursor solution, then transfer it to an inert atmosphere or a vacuum atmosphere for calcination to obtain a first modified electrode; Step 2: Soak the first modified electrode in a second precursor solution, then transfer it to an inert atmosphere or a vacuum atmosphere for calcination to obtain a second modified electrode; Step 3: Soak the second modified electrode in a third precursor solution, then transfer it to an inert atmosphere or a vacuum atmosphere for calcination to obtain a modified nickel-based electrode; The first precursor solution is a mixed solution of sodium hypophosphite solution and M1 metal salt solution, and M1 is any one or more than two of molybdenum, copper, iron, manganese, chromium, nickel and cobalt; The second precursor solution is a mixed solution of sodium hypophosphite solution and M2 metal salt solution, and M2 is any one or more than two of silver, platinum and iridium; The third precursor solution is any one or more than two of silver nitrate solution, chloroplatinic acid solution and chloroiridic acid solution.

[0051] The inventors have found that soaking the second modified electrode in a salt solution containing Ag, Pt and Ir metal elements and then calcining can form a third coating layer in the form of noble metal clusters or single atom sites on the surface of the second coating layer. The noble metal clusters or single atom sites have high specific surface area and special electronic structure, which exhibit excellent activity and selectivity in catalytic reactions, and are beneficial to further enhancing the catalytic activity of the nickel-based electrode.

[0052] Preferably, in steps 1-3, the temperature of the calcination is 200-500℃, and the time of the calcination is 0.1-1h.

[0053] Preferably, the concentration of sodium phosphite in the first precursor solution is 1-5mol / L, and the concentration of metal ions in the first precursor solution is 0.1-100mmol / L.

[0054] Preferably, the concentration of sodium phosphite in the second precursor solution is 1-5mol / L, and the concentration of M2 in the second precursor solution is 0.01-100mmol / L.

[0055] Preferably, the concentration of metal elements in the third precursor solution is 0.01-100mmol / L.

[0056] In some embodiments of the present application, the preparation method of the modified nickel-based electrode is as follows: Step 1: soaking the nickel-based electrode in a sodium phosphite solution, and then transferring to calcination under an inert atmosphere to obtain a first modified electrode; Step 2: soaking the first modified electrode in a precursor solution, and then transferring to calcination under an inert atmosphere to obtain a modified nickel-based electrode; The precursor solution is a mixed solution of a sodium phosphite solution and a M3 metal salt solution, and the M3 is silver, molybdenum and copper.

[0057] The inventors have found that, by first treating the nickel-based electrode with a sodium phosphite solution, the first coating layer is a phosphating layer (nickel phosphide Ni3P), which can regulate the coordination relationship between the second coating layer material and the nickel-based electrode, increase the bonding force between the second coating layer material and the nickel-based electrode, and reduce the risk of the second coating layer material falling off. Then, by treating the first modified electrode with a mixed solution of sodium phosphite and salt, the phosphorus element generated by the decomposition of sodium phosphite will also participate in the reaction between the metal salt solution and nickel, forming a Ni-X-P (X is molybdenum, copper, silver) alloy structure, making the alloy and the electrode substrate more firmly combined; some phosphorus-containing compounds generated by the side reaction between sodium phosphite and metal salt may form a transition layer between the alloy and the electrode substrate, further enhancing the bonding force between the active layer and the nickel-based electrode.

[0058] Preferably, in steps 1 and 2, the temperature of the calcination is 200-500℃, and the time of the calcination is 10-60min.

[0059] The inventors have found that, in the above-mentioned preferred temperature range, the metal precursor forms a heterojunction of phosphide and oxide, which enhances the adhesion between the coating layer and the nickel-based electrode, and improves the catalytic activity and structural stability of the nickel-based electrode. If the temperature is too low, the target product cannot be generated; if the temperature is too high, the first coating layer and the second coating layer are prone to agglomeration, which affects the structural stability of the nickel-based electrode.

[0060] Preferably, in step 2, the molar ratio of sodium phosphite, molybdenum ions, copper ions and silver ions in the mixed solution is 1:0.001-0.01:0.001-0.02:0.001-0.02; the concentration of sodium phosphite in the mixed solution is 2-3 mol / L; and the sum of the concentrations of molybdenum ions, copper ions and silver ions in the mixed solution is 1-20 mmol / L.

[0061] The inventors have found that, by controlling the relatively small concentration of metal ions and the relatively high concentration of sodium phosphite in the mixed solution, the phosphating effect of sodium phosphite is ensured, and the low concentration of metal ions provides a synergistic active site. If the concentrations of sodium phosphite and metal ions in the mixed solution are too high, the powder is prone to falling off, which affects the stability of the nickel-based electrode.

[0062] In other specific embodiments, the method for preparing the modified nickel-based electrode comprises the following steps: Step 1: immersing the nickel-based electrode in a sodium phosphite solution, and then transferring it to be calcined under an inert atmosphere to obtain a primary modified electrode; Step 2: immersing the primary modified electrode in a sodium phosphite solution again, and then transferring it to be calcined under an inert atmosphere to obtain a secondary modified electrode.

[0063] The first coating layer is obtained by calcining the sodium phosphite and the nickel-based electrode under an inert atmosphere, and the first coating layer is nickel phosphide (Ni3P). The first layer is very thin, and the second layer is further treated with sodium phosphite, which increases the electrode area and improves the catalytic performance of the nickel phosphide.

[0064] Preferably, in steps 1 and 2, the calcination temperature is 200-500°C, the calcination time is 10-60 min, and the concentration of the sodium phosphite solution is 0.5-3.0 mol / L.

[0065] The inventors have found that, after soaking in a sodium phosphite solution and then calcining, the nickel-based electrode will react with the sodium phosphite on the surface of the nickel-based electrode to form a compound coating layer containing phosphorus elements, which can improve the surface properties of the nickel-based electrode, such as improving the conductivity, stability and corrosion resistance of the electrode. At the same time, it can also serve as an intermediate layer to provide a better foundation for subsequent modification steps, which is conducive to the formation and combination of the second coating layer during the secondary modification. The second coating layer is similar to the first coating layer and is also composed of phosphorus-containing compounds generated by the reaction of sodium phosphite under specific conditions. By adjusting the reaction conditions, such as the concentration of the sodium phosphite solution, the calcination temperature, etc., which are different from step 1, the generated coating layer will have different characteristics, which may result in differences in the degree of crystallization or chemical bonding of the generated phosphorus-containing compounds, further improving the performance of the catalytic electrode and enhancing the catalytic activity of the electrode and reducing the polarization of the electrode. The second coating layer and the first coating layer work together to improve the overall performance of the nickel-based electrode, making it more suitable for specific application scenarios such as electrochemical catalysis, electrolysis, etc.

[0066] In a second aspect, the present application provides a modified nickel-based electrode prepared by the above preparation method.

[0067] Preferably, the modified nickel-based electrode comprises a substrate and a first coating layer, a second coating layer, …, and an Nth coating layer, where N is an integer; the substrate is a nickel-based material; the first coating layer at least coats part of the surface of the substrate, the second coating layer at least coats part of the surface of the material composed of the substrate and the first coating layer, and the Nth coating layer at least coats part of the surface of the material composed of the substrate and the first coating layer, the second coating layer, …, and the (N-1)th coating layer.

[0068] Preferably, 0≤N≤5.

[0069] In a third aspect, the present application provides a device for continuous production of a modified nickel-based electrode, comprising a reel one, a reel two and a plurality of modification devices arranged between the reel one and the reel two, the reel one being used for unwinding the nickel-based electrode, and the reel two being used for winding the nickel-based electrode; the plurality of modification devices are arranged in sequence along the moving direction of the nickel-based electrode, and each modification device comprises a soaking pool and a calcining furnace, the soaking pool being arranged upstream of the calcining furnace.

[0070] Preferably, it further comprises a plurality of redirection reels, the redirection reels being rotationally arranged, and the plurality of redirection reels are arranged at intervals along the moving direction of the nickel-based electrode.

[0071] Preferably, the height positions of adjacent two redirection reels are different, so as to adjust the moving direction of the nickel-based electrode or support the nickel-based electrode.

[0072] In order to make the technical problems, technical solutions and technical advantages to be solved by the present application clearer, specific examples will be described in detail below, but the protection scope of the present application is not limited to the following specific examples.

[0073] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The professional terms used herein are only for the purpose of describing specific examples and are not intended to limit the protection scope of the present application.

[0074] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present application can be purchased from the market or can be prepared by existing methods.

[0075] Example 1: Reference Figure 1 A device for continuous production of modified nickel-based electrodes, comprising a winding drum 1, a winding drum 2, a plurality of modification devices 3 arranged between the winding drum 1 and the winding drum 2, and a plurality of redirection rolls 4, the winding drum 1 is used to unwind the nickel-based electrode, the winding drum 2 is used to wind the nickel-based electrode, in actual application, a support frame is arranged below each of the winding drum 1 and the winding drum 2, the support frame is used to support the winding drum 1 (the winding drum 2), the winding drum 1 (the winding drum 2) is rotatably connected to the support frame, in order to facilitate movement, a movable roller and a limiting brake for fixing the position of the support frame can also be arranged below the support frame.

[0076] The plurality of modification devices 3 are arranged in sequence along the moving direction of the nickel-based electrode, each modification device 3 comprises a soaking pool 3.1 and a calcination furnace 3.2, and the soaking pool 3.1 is arranged upstream of the calcination furnace 3.2. In the specific embodiment of the present application, the modification device 3 is arranged as two groups along the moving direction of the nickel-based electrode, in sequence, a first soaking pool 3.1, a first calcination furnace 3.2, a second soaking pool 3.1 and a second calcination furnace 3.2.

[0077] When modifying the nickel-based electrode, the winding drum 1 is rotated to unwind the nickel-based electrode wound on the winding drum 1, so that one segment of the nickel-based electrode enters the first soaking pool 3.1 for a period of time, then the winding drum 1 is continuously rotated to unwind the nickel-based electrode, and at the same time, the winding drum 2 is rotated to wind the nickel-based electrode, so that the treated segment of the nickel-based electrode enters the first calcination furnace 3.2, after calcination is completed, the winding and unwinding procedures are repeated, and multiple segments of the nickel-based electrode can be treated at the same time, realizing continuous production.

[0078] The redirection roll 4 is rotatably arranged, and a plurality of redirection rolls 4 are arranged in sequence along the moving direction of the nickel-based electrode. The height positions of adjacent two redirection rolls 4 are different, so as to adjust the moving direction of the nickel-based electrode, on the one hand, other equipment in the production site can be avoided; on the other hand, the nickel-based electrode can be supported, and the possibility of deformation of the nickel-based electrode due to gravity is reduced.

[0079] In actual production process, a certain distance is required to be set between the soaking tank 3.1 and the roasting furnace 3.2 to avoid the mutual influence of the two devices. In order to improve the utilization rate of the nickel-based electrode and avoid that part of the nickel-based electrode is not treated, preferably, the lengths of the nickel-based electrode treated in the soaking tank 3.1 and the roasting furnace 3.2 are consistent, and the length of the nickel-based electrode between the roasting furnace 3.2 and the soaking tank 3.1 is an integer multiple of the length of the nickel-based electrode treated in the soaking tank 3.1 (or the roasting furnace 3.2).

[0080] Example 2: A preparation method of a modified nickel-based electrode, comprising the following steps: Step 1, mixing nickel nitrate, iron nitrate, sodium phosphite and water to obtain a first precursor solution, the concentration of nickel nitrate in the first precursor solution is 2 mmol / L, the concentration of iron nitrate in the first precursor solution is 8 mmol / L, and the concentration of sodium phosphite in the first precursor solution is 2 mol / L. The nickel-based fiber cloth is soaked in the first precursor solution for 15 min, then the nickel-based fiber cloth is moved to a roasting furnace, and is roasted at 350°C under a reducing atmosphere for 30 min to obtain a first modified electrode.

[0081] Step 2, mixing chromium nitrate and sodium phosphite to obtain a second precursor solution, the concentration of chromium nitrate in the second precursor solution is 2 mmol / L, and the concentration of sodium phosphite in the second precursor solution is 2 mol / L. The first modified electrode is soaked in the second precursor solution for 15 min, and then the first modified electrode is transferred to a roasting furnace and is roasted at 350°C under an inert atmosphere for 60 min to obtain a modified nickel-based electrode.

[0082] Example 3: A preparation method of a modified nickel-based electrode, comprising the following steps: Step 1, mixing sodium molybdate, copper nitrate, sodium phosphite and water to obtain a first precursor solution, the concentration of sodium molybdate in the first precursor solution is 10 mmol / L, the concentration of copper nitrate in the first precursor solution is 2 mmol / L, and the concentration of sodium phosphite in the first precursor solution is 1 mol / L. The nickel-based fiber cloth is soaked in the first precursor solution for 30 s, then the nickel-based fiber cloth is moved to a roasting furnace, and is roasted at 100°C under a reducing atmosphere for 10 min to obtain a first modified electrode.

[0083] Step 2, mixing copper chloride and sodium phosphite to obtain a second precursor solution, the concentration of copper chloride in the second precursor solution is 10 mmol / L, and the concentration of sodium phosphite in the second precursor solution is 1 mol / L. The first modified electrode is soaked in the second precursor solution for 30 s, and then the first modified electrode is transferred to a roasting furnace and is roasted at 100°C under an inert atmosphere for 10 min to obtain a modified nickel-based electrode.

[0084] Example 4: A preparation method of a modified nickel-based electrode, comprising the following steps: Step 1, mixing manganese nitrate, cobalt nitrate, sodium hypophosphite and water to obtain a first precursor solution, the concentration of nickel nitrate in the first precursor solution is 20 mmol / L, the concentration of iron nitrate in the first precursor solution is 5 mmol / L, and the concentration of sodium hypophosphite in the first precursor solution is 3 mol / L. The nickel-based fiber cloth is soaked in the first precursor solution for 30 min, and then the nickel-based fiber cloth is moved to a calcination furnace and calcined at 500°C under a reducing atmosphere for 60 min to obtain a first modified electrode.

[0085] Step 2, mixing silver nitrate, sodium hypophosphite and water to obtain a second precursor solution, the concentration of silver nitrate in the second precursor solution is 5 mmol / L, and the concentration of sodium hypophosphite in the second precursor solution is 3 mol / L. The first modified electrode is soaked in the second precursor solution for 30 min, and then the first modified electrode is transferred to a calcination furnace and calcined at 500°C under an inert atmosphere for 60 min to obtain a modified nickel-based electrode.

[0086] Comparative Example 1: A preparation method of a modified nickel-based electrode, comprising: mixing nickel nitrate, iron nitrate and water to obtain a precursor solution, the concentration of nickel nitrate in the precursor solution is 2 mmol / L, and the concentration of iron nitrate in the precursor solution is 8 mmol / L. The nickel-based fiber cloth is soaked in the precursor solution for 15 min, and then the nickel-based fiber cloth is moved to a calcination furnace and calcined at 350°C under a reducing atmosphere for 30 min to obtain a modified nickel-based electrode.

[0087] Comparative Example 2: A preparation method of a modified nickel-based electrode, comprising: mixing nickel nitrate, iron nitrate and water to obtain a precursor solution, the concentration of nickel nitrate in the precursor solution is 2 mmol / L, and the concentration of iron nitrate in the precursor solution is 8 mmol / L. The nickel-based fiber cloth is soaked in the precursor solution for 15 min, and then the nickel-based fiber cloth is moved to a calcination furnace and calcined at 350°C under a reducing atmosphere for 30 min to obtain a modified nickel-based electrode.

[0088] Comparative Example 3: A preparation method of a modified nickel-based electrode, comprising: soaking the nickel-based fiber cloth in a 2 mol / L sodium hypophosphite solution for 15 min, and then moving the nickel-based fiber cloth to a calcination furnace and calcining at 350°C under a reducing atmosphere for 30 min to obtain a modified nickel-based electrode.

[0089] Example 5: A preparation method of a modified nickel-based electrode, comprising the following steps: Step 1, mixing sodium phosphite, ferric nitrate, cobalt nitrate, nickel nitrate, manganese nitrate and water to obtain a first precursor solution A, the concentration of sodium phosphite in the first precursor solution is 1.33 mol / L, the concentrations of ferric nitrate, cobalt nitrate, nickel nitrate and manganese nitrate in the first precursor solution A are 6 mmol / L, 3 mmol / L, 18 mmol / L and 12 mmol / L respectively. The nickel-based fiber cloth is soaked in the first precursor solution for 15 min, then the nickel-based fiber cloth is moved to a calcination furnace and calcined at 300 DEG C for 30 min under a reducing atmosphere to obtain a first modified electrode; Step 2, mixing sodium phosphite, silver nitrate and water to obtain a second precursor solution B, the concentration of sodium phosphite in the second precursor solution B is 3 mol / L, the concentration of silver nitrate in the second precursor solution B is 01 mmol / L, the first modified electrode is soaked in the second precursor solution for 15 min, then the first modified electrode is moved to a calcination furnace and calcined at 350 DEG C for 60 min under a reducing atmosphere to obtain a second modified electrode.

[0090] Step 3, the above nickel-based fiber cloth is soaked in chloroplatinic acid with a concentration of 005 mmol for 15 min, then the nickel-based fiber cloth is moved to a calcination furnace and calcined at 200 DEG C for 60 min under a reducing atmosphere to obtain a modified nickel-based electrode.

[0091] Example 6: A preparation method of a modified nickel-based electrode, comprising the following steps: Step 1, mixing sodium phosphite, ferric nitrate, cobalt nitrate, nickel nitrate, manganese nitrate and water to obtain a first precursor solution, the concentration of sodium phosphite in the first precursor solution is 2.5 mol / L, the concentrations of ferric nitrate, cobalt nitrate, nickel nitrate and manganese nitrate in the first precursor solution A are 20 mmol / L, 5 mmol / L, 5 mmol / L and 5 mmol / L respectively. The nickel-based fiber cloth is soaked in the first precursor solution for 10 min, then the nickel-based fiber cloth is moved to a calcination furnace and calcined at 200 DEG C for 20 min under a reducing atmosphere to obtain a first modified electrode; Step 2, mixing sodium phosphite, silver nitrate and water to obtain a second precursor solution, the concentration of sodium phosphite in the second precursor solution is 1 mol / L, the concentration of silver nitrate in the second precursor solution is 10 mmol / L, the first modified electrode is soaked in the second precursor solution for 10 min, then the first modified electrode is moved to a calcination furnace and calcined at 200 DEG C for 60 min under a reducing atmosphere to obtain a second modified electrode.

[0092] Step 3, the nickel-based fiber cloth is soaked in a 5mmol concentration of chloroplatinic acid solution for 15 minutes, and then the nickel-based fiber cloth is moved to a calcination furnace and calcined at 200℃ for 60 minutes in a reducing atmosphere to obtain a modified nickel-based electrode.

[0093] Example 7: A method for preparing a modified nickel-based electrode comprises the following steps: Step 1, a first precursor solution A is prepared by mixing sodium phosphite, ferric nitrate, cobalt nitrate, nickel nitrate, manganese nitrate and water, the concentration of sodium phosphite in the first precursor solution is 5mol / L, and the concentrations of ferric nitrate, cobalt nitrate, nickel nitrate and manganese nitrate in the first precursor solution A are 5mmol / L, 5mmol / L, 15mmol / L and 5mmol / L respectively. The nickel-based fiber cloth is soaked in the first precursor solution for 10 minutes, and then the nickel-based fiber cloth is moved to a calcination furnace and calcined at 200℃ for 20 minutes in a reducing atmosphere to obtain a first modified electrode. Step 2, a second precursor solution B is prepared by mixing sodium phosphite, silver nitrate and water, the concentration of sodium phosphite in the second precursor solution B is 1mol / L, and the concentration of silver nitrate in the second precursor solution B is 5mmol / L. The first modified electrode is soaked in the second precursor solution for 10 minutes, and then the first modified electrode is moved to a calcination furnace and calcined at 500℃ for 60 minutes in a reducing atmosphere to obtain a second modified electrode.

[0094] Step 3, the nickel-based fiber cloth is soaked in a 5mmol concentration of chloroplatinic acid solution for 15 minutes, and then the nickel-based fiber cloth is moved to a calcination furnace and calcined at 200℃ for 60 minutes in a reducing atmosphere to obtain a modified nickel-based electrode.

[0095] Example 8: A method for preparing a modified nickel-based electrode comprises the following steps: Step 1, the nickel-based fiber cloth is soaked in a 1.33mol / L concentration of sodium phosphite solution for 15 minutes, and then the nickel-based fiber cloth is moved to a calcination furnace and calcined at 350℃ for 30 minutes in a reducing atmosphere to obtain a first modified electrode. Step 2, a mixed solution is prepared by mixing a sodium phosphite solution, silver nitrate, sodium molybdate and copper chloride, the molar ratio of sodium phosphite, silver ions, molybdenum ions and copper ions in the mixed solution is 1:0.01:0.02:0.02, the concentration of sodium phosphite in the mixed solution is 2.5mol / L, and the sum of the concentrations of silver ions, molybdenum ions and copper ions in the mixed solution is 10mmol / L. Then the first modified electrode is soaked in the mixed solution for 15 minutes, and then the soaked first modified electrode is moved to a calcination furnace and calcined at 350℃ for 60 minutes in an inert atmosphere to obtain a modified nickel-based electrode.

[0096] Example 9: A preparation method of a modified nickel-based electrode, comprising the following steps: Step 1, immerse the nickel-based fiber cloth in a sodium phosphite solution with a concentration of 1.33 mol / L for 15 min, then move the nickel-based fiber cloth to a calcination furnace, and calcine at 200℃ for 10 min under a reducing atmosphere to obtain a primary modified electrode; Step 2, mix sodium phosphite solution, silver nitrate, sodium molybdate, and copper chloride to obtain a mixed solution, the molar ratio of sodium phosphite, silver ions, molybdenum ions, and copper ions in the mixed solution is 1:0.001:0.001:0.001, the concentration of sodium phosphite in the mixed solution is 2.5 mol / L, and the sum of the concentrations of silver particles, molybdenum ions, and copper ions in the mixed solution is 1 mol / L; then immerse the primary modified electrode in the mixed solution for 15 min, and then move the immersed primary modified electrode to a calcination furnace and calcine at 200℃ for 10 min under an inert atmosphere to obtain a modified nickel-based electrode.

[0097] Example 10: A preparation method of a modified nickel-based electrode, comprising the following steps: Step 1, immerse the nickel-based fiber cloth in a sodium phosphite solution with a concentration of 1.33 mol / L for 15 min, then move the nickel-based fiber cloth to a calcination furnace, and calcine at 400℃ for 50 min under a reducing atmosphere to obtain a primary modified electrode; Step 2, mix sodium phosphite solution, silver nitrate, sodium molybdate, and copper chloride to obtain a mixed solution, the molar ratio of sodium phosphite, silver ions, molybdenum ions, and copper ions in the mixed solution is 1:0.005:0.01:0.01, the concentration of sodium phosphite in the mixed solution is 2.5 mol / L, and the sum of the concentrations of silver particles, molybdenum ions, and copper ions in the mixed solution is 20 mmol / L; then immerse the primary modified electrode in the mixed solution for 15 min, and then move the immersed primary modified electrode to a calcination furnace and calcine at 450℃ for 55 min under an inert atmosphere to obtain a modified nickel-based electrode.

[0098] Figure 2 The SEM image of the nickel-based fiber cloth used in Examples 2-14 and Comparative Examples 1-3 is shown in FIG. 1, and the surface of the nickel-based fiber is smooth without modification treatment.

[0099] Figure 3 The SEM image of the modified nickel-based electrode prepared in Example 5 is shown in FIG. 2, and the surface of the modified nickel-based electrode is rough and flaky. Figure 3 It can be seen that the surface of the modified nickel-based electrode is rough and flaky, which proves that the nickel-based fiber cloth is successfully coated with a coating layer.

[0100] Figure 4 The SEM image of the modified nickel-based electrode prepared in Example 8 is shown in FIG. 4, and the surface of the modified nickel-based electrode is rough and flaky. Figure 4It can be seen that the modified nickel-based electrode surface is rough and needle-shaped. According to the surface morphology, the inventors speculate that the nickel-based fiber cloth surface is successfully coated with metal ion doped nickel phosphide particles.

[0101] The nickel-based fiber cloth prepared in Examples 2-12, Comparative Examples 1-3 and without treatment was used as a catalytic electrode, and a 6M KOH solution was used as an electrolyte solution to test the alkaline electrolytic cell.

[0102] Figure 5 The nickel-based electrode prepared in Examples 2-4, Comparative Examples 1-3 of the present application was used as a catalytic electrode for alkaline electrolytic cell test. Figure 5 It can be seen that the catalytic activity of the catalytic electrode can be improved by twice treating the nickel-based electrode with a sodium phosphite and metal salt solution.

[0103] Figure 6 The nickel-based electrode prepared in Examples 5-7 of the present application was used as a catalytic electrode for alkaline electrolytic cell test. Figure 6 It can be seen that the catalytic activity of the nickel-based electrode obtained by treating the precursor solution three times is good.

[0104] Figure 7 The nickel-based electrode prepared in Examples 8-10 of the present application was used as a catalytic electrode for alkaline electrolytic cell test. Figure 6 It can be seen that the catalytic activity of the catalytic electrode can be improved by first coating with a sodium phosphite solution and second coating with a mixed solution containing molybdenum, copper and silver.

[0105] In Examples 2-4, Examples 5-7 and Examples 8-10, there is a certain difference in the catalytic activity of the prepared catalytic electrode. The inventors speculate that the reasons for the difference may be: first, the metal salt solution added in different examples is different, and the performance difference between different metal elements affects the catalytic activity of the catalytic electrode; second, the concentration of the metal salt affects the catalytic activity of the catalytic electrode.

[0106] The above-described embodiments are only preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can make equivalent replacements or changes to the technical solutions and concepts of the present application within the technical scope of the present application, which should be covered within the protection scope of the present application.

Claims

1. A method for preparing a modified nickel-based electrode, characterized in that, The method comprises the following steps: Step 1, the nickel-based electrode is soaked in a precursor solution, and then is transferred to an inert atmosphere or a vacuum atmosphere for calcination to obtain a primary modified electrode; Step 2, step 1 is repeated one or more times to obtain the modified nickel-based electrode; The precursor solution is any one or more than two of a sodium phosphite solution and a metal M salt solution.

2. The method for preparing a modified nickel-based electrode according to claim 1, wherein The metal element in the metal M salt solution is any one or more than two of molybdenum, copper, silver, iron, manganese, chromium, nickel, cobalt, platinum and iridium; the metal M salt solution is any one or more than two of a nitrate solution, a chloride solution and a sulfate solution; when the metal element M is molybdenum, the metal M salt is sodium molybdate; The nickel-based electrode is any one of a nickel-based fiber cloth and a flexible nickel mesh; In step 1, the soaking time is 30 s to 30 min; In step 1, the calcination temperature is 100 to 500 DEG C, and the calcination time is 10 to 60 min.

3. The method for preparing a modified nickel-based electrode according to claim 1 or 2, characterized in that, The method comprises the following steps: Step 1, the nickel-based electrode is soaked in a precursor solution, and then is transferred to an inert atmosphere or a vacuum atmosphere for calcination to obtain a primary modified electrode; Step 2, the primary modified electrode is soaked in a precursor solution, and then is transferred to an inert atmosphere or a vacuum atmosphere for calcination to obtain a modified nickel-based electrode; The precursor solution is a mixed solution of a sodium phosphite solution and a metal M salt solution.

4. The method for preparing a modified nickel-based electrode according to claim 3, wherein the nickel-based electrode is a nickel hydroxide electrode. In steps 1 and 2, the calcination temperature is 200 to 500 DEG C, and the calcination time is 0.1 to 1 h; The concentration of sodium phosphite in the precursor solution is 1 to 3 mol / L, and the concentration of M in the precursor solution is 10 to 50 mmol / L.

5. The method for preparing a modified nickel-based electrode according to claim 1 or 2, wherein the nickel-based electrode is a nickel hydroxide electrode. The method comprises the following steps: Step 1, the nickel-based electrode is soaked in a first precursor solution, and then is transferred to an inert atmosphere or a vacuum atmosphere for calcination to obtain a primary modified electrode; Step 2, the primary modified electrode is again soaked in a second precursor solution, and then is transferred to an inert atmosphere or a vacuum atmosphere for calcination to obtain a secondary modified electrode; Step 3, the secondary modified electrode is soaked in a third precursor solution, and then is transferred to an inert atmosphere or a vacuum atmosphere for calcination to obtain a modified nickel-based electrode; The first precursor solution is a mixed solution of a sodium phosphite solution and a M1 metal salt solution, and M1 is any one or more than two of molybdenum, copper, iron, manganese, chromium, nickel and cobalt; The second precursor solution is a mixed solution of a sodium phosphite solution and a M2 metal salt solution, and M2 is any one or more than two of silver, platinum and iridium; The third precursor solution is any one or more than two of a silver nitrate solution, a chloroplatinic acid solution and a chloroiridic acid solution.

6. The method for preparing a modified nickel-based electrode according to claim 5, wherein the nickel-based electrode is immersed in the aqueous solution of the complexing agent and the oxidizing agent at a temperature of 20 to 80°C for 1 to 24 hours. In steps 1 to 3, the calcination temperature is 200 to 500 DEG C, and the calcination time is 0.1 to 1 h; The concentration of sodium phosphite in the first precursor solution is 1 to 5 mol / L, and the concentration of M1 in the first precursor solution is 0.1 to 100 mmol / L; The concentration of sodium phosphite in the second precursor solution is 1 to 5 mol / L, and the concentration of M2 in the second precursor solution is 0.01 to 100 mmol / L; The concentration of the metal elements in the third precursor solution is 0.01-100 mmol / L.

7. The method for preparing a modified nickel-based electrode according to claim 1 or 2, wherein the nickel-based electrode is a nickel hydroxide electrode. The method comprises the following steps: Step 1: placing a nickel-based electrode in a sodium phosphite solution for immersion, and then transferring to calcination under an inert atmosphere to obtain a first modified electrode; Step 2: placing the first modified electrode in a precursor solution for immersion, and then transferring to calcination under an inert atmosphere to modify the nickel-based electrode; The precursor solution is a mixed solution of a sodium phosphite solution and a M3 metal salt solution, and the M3 is silver, molybdenum and copper.

8. The method for preparing the modified nickel-based electrode as described in claim 7, characterized in that, In steps 1 and 2, the calcination temperature is 200-500 DEG C, and the calcination time is 10-60 min. In step 1, the concentration of the sodium phosphite solution is 0.5-3.0 mol / L. In step 2, the molar ratio of sodium phosphite, molybdenum ions, copper ions and silver ions in the mixed solution is 1:0.001-0.01:0.001-0.02:0.001-0.02; the concentration of sodium phosphite in the mixed solution is 2-3 mol / L; and the sum of the concentrations of molybdenum ions, copper ions and silver ions in the mixed solution is 1-20 mmol / L.

9. A modified nickel-based electrode, characterized in that, The modified nickel-based electrode is prepared by the preparation method of any one of claims 1-8.

10. The modified nickel-based electrode of claim 9, wherein, The modified nickel-based electrode comprises a substrate and a first coating layer, a second coating layer and an Nth coating layer, wherein N is an integer; the substrate is a nickel-based material; the first coating layer is at least coated on part of the surface of the substrate; the second coating layer is at least coated on part of the surface of the material composed of the substrate and the first coating layer; the Nth coating layer is at least coated on part of the surface of the material composed of the substrate, the first coating layer, the second coating layer and the (N-1)th coating layer; and 0≤N≤5.

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