Preparation method of high-entropy alloy-based catalyst, catalyst and zinc-air battery

Abstract

The application discloses a preparation method of a high-entropy alloy-based catalyst, a catalyst and a zinc-air battery, and belongs to the technical field of catalyst preparation. The preparation method comprises the following steps: providing iron nitrate, cobalt nitrate, nickel nitrate, manganese nitrate, ammonium dimolybdate, stannous chloride and multi-walled carbon nanotubes; dissolving the iron nitrate, the cobalt nitrate, the nickel nitrate, the manganese nitrate, the ammonium dimolybdate and the stannous chloride in a target solution to form an initial mixed solution; adding the multi-walled carbon nanotubes into the initial mixed solution to form an intermediate mixed solution; heating the intermediate mixed solution until all the liquid in the intermediate mixed solution is evaporated to form an initial powder; and performing thermal shock on the initial powder to obtain the high-entropy alloy-based catalyst.

Description

Technical Field

[0001] This application belongs to the field of catalyst preparation technology, specifically relating to a method for preparing a high-entropy alloy-based catalyst, the catalyst, and a zinc-air battery. Background Technology

[0002] Zinc-air batteries (ZABs) can provide a theoretical energy density of up to 1220 Wh / kg and have a moderate operating voltage. Their aqueous electrolyte ensures higher safety and reduces the risk of overheating and combustion. Furthermore, the abundant availability of zinc resources improves the cost-effectiveness of ZABs, making them economical and reducing the overall cost of energy storage systems. Simultaneously, ZABs contain no hazardous substances, and both zinc and air components are recyclable. This excellent environmental characteristic fully meets the requirements of sustainable development, making them an ideal energy storage option. However, the activity and stability of the catalyst on its air electrode remain major limitations to its commercial application. The overall electrochemical performance of ZABs is fundamentally determined by the catalytic efficiency of the air electrode. The oxygen reduction and oxygen evolution reaction activity of the electrocatalyst plays a crucial role in the battery's energy conversion efficiency and operational durability. However, among related technologies, the performance of catalysts in zinc-air batteries is relatively poor. Summary of the Invention

[0003] This application aims to provide a method for preparing a high-entropy alloy-based catalyst, the catalyst itself, and a zinc-air battery, thereby at least solving the problem of poor catalyst performance in the prepared zinc-air battery.

[0004] To solve the above-mentioned technical problems, this application is implemented as follows: In a first aspect, embodiments of this application provide a method for preparing a high-entropy alloy-based catalyst, the method comprising: It provides nitrate-based iron salts, nitrate-based cobalt salts, nitrate-based nickel salts, nitrate-based manganese salts, ammonium molybdate, stannous chloride, and multi-walled carbon nanotubes; The iron salt, cobalt salt, nickel salt, manganese salt, ammonium molybdate, and stannous chloride of the nitrate system are dissolved in the target solution to form an initial mixed solution. The multi-walled carbon nanotubes are added to the initial mixed solution to form an intermediate mixed solution; The intermediate mixture is heated until all the liquid in the intermediate mixture evaporates to form the initial powder; The initial powder was subjected to thermal shock to obtain a high-entropy alloy-based catalyst.

[0005] Optionally, the molar ratio of the nitric acid-based iron salt, the nitric acid-based cobalt salt, the nitric acid-based nickel salt, the nitric acid-based manganese salt, the ammonium molybdate, and the stannous chloride is 1: 1: 1: 0.1: x: y; Where 1.2≤x≤1.8, 0<y≤0.15.

[0006] Optionally, the mass of the multi-walled carbon nanotube is M1, and the sum of the masses of the six nitrate-based iron salt, nitrate-based cobalt salt, nitrate-based nickel salt, nitrate-based manganese salt, ammonium molybdate, and stannous chloride is M2, satisfying: 1 / 5M2≤M1≤1 / 3M2.

[0007] Optionally, the target solution includes at least one of anhydrous ethanol and deionized water.

[0008] Optionally, the nitric acid-based iron salt, the nitric acid-based cobalt salt, the nitric acid-based nickel salt, the nitric acid-based manganese salt, the ammonium molybdate, and the stannous chloride are dissolved in the target solution to form an initial mixed solution, comprising: The iron salt, cobalt salt, nickel salt, manganese salt, ammonium molybdate, and stannous chloride of the nitrate system are dissolved in the target solution and subjected to ultrasonic treatment to obtain the initial mixed solution.

[0009] Optionally, heating the intermediate mixture until all the liquid in the intermediate mixture evaporates includes: The intermediate mixture is placed in a heating device, and the temperature in the heating device is within a first set temperature range. The intermediate mixture is heated by the heating device until all the liquid in the intermediate mixture evaporates.

[0010] Optionally, the thermal shock of the initial powder includes: The initial powder is placed in a Joule thermal shock apparatus and subjected to thermal shock by the Joule thermal shock apparatus.

[0011] Optionally, the initial powder is subjected to thermal shock using the Joule thermal shock apparatus, including: The duration of thermal shock of the initial powder by the Joule thermal shock device is within a set duration range, and the impact temperature of the Joule thermal shock device is within a second set temperature range.

[0012] Secondly, embodiments of this application provide a high-entropy alloy-based catalyst, which is prepared by the preparation method described in any one of the first aspects above, and the high-entropy alloy catalyst includes iron, cobalt, nickel, manganese, molybdenum and tin.

[0013] Thirdly, embodiments of this application provide a zinc-air battery, which includes the high-entropy alloy-based catalyst described in the second aspect above.

[0014] In this embodiment, nitric acid-based iron salts, nitric acid-based cobalt salts, nitric acid-based nickel salts, nitric acid-based manganese salts, ammonium molybdate, stannous chloride, and multi-walled carbon nanotubes are provided. These nitric acid-based iron salts, cobalt salts, nickel salts, manganese salts, ammonium molybdate, and stannous chloride are dissolved in a target solution to form an initial mixed solution. Multi-walled carbon nanotubes are added to the initial mixed solution to form an intermediate mixed solution. The intermediate mixed solution is heated until all liquid in the intermediate mixed solution evaporates to form an initial powder. The initial powder is then subjected to thermal shock to obtain a high-entropy alloy-based catalyst. That is, in this embodiment, the prepared high-entropy alloy-based catalyst has FeCoNiMnMoSn high-entropy alloy and Mo2C, which is equivalent to the high-entropy alloy-based catalyst having FeCoNiMnMoSn high-entropy alloy and Mo2C as dual active sites. The synergistic effect between the dual active sites promotes the catalytic activity and stability, resulting in the high-entropy alloy catalyst exhibiting good catalytic activity and stability. In addition, the introduction of Sn can cause lattice distortion, thereby promoting the improvement of catalytic performance. This results in a high-entropy alloy catalyst that not only has good catalytic activity and stability, but also good catalytic performance. Attached Figure Description

[0015] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a flowchart illustrating a method for preparing a high-entropy alloy-based catalyst according to an embodiment of this application; Figure 2 The image shows the XRD pattern of the high-entropy alloy-based catalyst prepared by the method in Example 1 of this application; Figure 3 This shows a scanning electron microscope image of the high-entropy alloy-based catalyst prepared by the method in Example 1 of this application; Figure 4 This image shows a transmission electron microscope image of the high-entropy alloy-based catalyst prepared by the method in Example 1 of this application. Figure 5 This shows the elemental distribution of the high-entropy alloy-based catalyst prepared by the method in Example 1 of this application; Figure 6The graph shows the polarization curves of the high-entropy alloy-based catalyst prepared by the method in Example 1 of this application and a commercially available RuO2 catalyst in 1 M KOH solution for the electrocatalytic oxygen evolution reaction (OER). Figure 7 This diagram shows the specific capacity of a zinc-air battery assembled with a high-entropy alloy-based catalyst prepared by the method in Example 1 of this application. Figure 8 This diagram shows the rate performance of a zinc-air battery assembled with a high-entropy alloy-based catalyst prepared by the method in Example 1 of this application. Detailed Implementation

[0016] The embodiments of this application will now be described in detail. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0017] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "multiple" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0018] This application provides a method for preparing a high-entropy alloy-based catalyst, such as... Figure 1 As shown, the preparation method of this high-entropy alloy-based catalyst includes: Step 101: Provide nitrate-based iron salts, nitrate-based cobalt salts, nitrate-based nickel salts, nitrate-based manganese salts, ammonium molybdate, stannous chloride, and multi-walled carbon nanotubes.

[0019] Among them, nitric acid-based iron salts can be ferric nitrate nonahydrate (Fe(NO3)3·9H2O) and ferric nitrate hexahydrate (Fe(NO3)3·6H2O), etc. Nitric acid-based cobalt salts can be cobalt nitrate hexahydrate (Co(NO3)2·6H2O) and cobalt nitrate (Co(NO3)2), etc. Nitric acid-based nickel salts can be nickel nitrate hexahydrate (Ni(NO3)2·6H2O) and nickel nitrite (Ni(NO2)2), etc. Nitric acid-based manganese salts can be anhydrous manganese nitrate (Mn(NO3)2), manganese nitrate tetrahydrate (Mn(NO3)2·4H2O), and manganese nitrate hexahydrate (Mn(NO3)2·6H2O), etc.

[0020] In addition, there are nitrate-based iron salts, nitrate-based cobalt salts, nitrate-based nickel salts, nitrate-based manganese salts, and ammonium paramolybdate ((NH4)6Mo7O). 24 Both stannous chloride (SnCl2) and stannous chloride (SnCl2) can be in block or powder form.

[0021] For example, Fe(NO3)3·9H2O, Co(NO3)2·6H2O, Ni(NO3)2·6H2O, Mn(NO3)2·4H2O, (NH4)6Mo7O are provided 24 And SnCl2, Fe(NO3)3·9H2O, Co(NO3)2·6H2O, Ni(NO3)2·6H2O, Mn(NO3)2·4H2O, (NH4)6Mo7O 24 Both SnCl2 and SnCl2 are available in powder form or in block form.

[0022] In some implementations, the molar ratio of the six nitrate-based iron salts, nitrate-based cobalt salts, nitrate-based nickel salts, nitrate-based manganese salts, ammonium molybdate, and stannous chloride is 1: 1: 1: 0.1: x: y; where 1.2 ≤ x ≤ 1.8 and 0 < y ≤ 0.15.

[0023] Where x can be any value from 1.2 to 1.8, and y can be any value from 0 to 0.15. For example, when x is 1.6 and y is 0.1, the molar ratio of the six nitrate-based iron salts, nitrate-based cobalt salts, nitrate-based nickel salts, nitrate-based manganese salts, ammonium molybdate, and stannous chloride is 1: 1: 1: 0.1: 1.6: 0.1. Specifically, this can make Fe(NO3)3·9H2O, Co(NO3)2·6H2O, Ni(NO3)2·6H2O, Mn(NO3)2·4H2O, and (NH4)6Mo7O 24 The molar ratio of these six substances, including SnCl2, is 1:1:1:0.1:1.6:0.1. For example, when x is 1.2 and y is 0.05, the molar ratio of the following six substances is equivalent to 1:1:1:0.1:1.2:0.05: Fe(NO3)3·9H2O, Co(NO3)2·6H2O, Ni(NO3)2·6H2O, Mn(NO3)2·4H2O, and (NH4)6Mo7O. 24 The molar ratio of these six components, including SnCl2, is 1: 1: 1: 0.1:1.2: 0.05.

[0024] In some implementations, the mass of the multi-walled carbon nanotubes is M1, and the sum of the masses of the six nitrate-based iron salt, nitrate-based cobalt salt, nitrate-based nickel salt, nitrate-based manganese salt, ammonium molybdate, and stannous chloride is M2, satisfying: 1 / 5M2≤M1≤1 / 3M2. This arrangement avoids excessive use of multi-walled carbon nanotubes and ensures a moderate mass, facilitating the subsequent formation of high-entropy alloy-based catalysts.

[0025] Where M1 can be any value from 1 / 5M2 to 1 / 3M2. For example, if M1 is 1 / 5M2, then the mass of multi-walled carbon nanotubes is equivalent to one-fifth of the total mass of the six nitrate-based iron salts, nitrate-based cobalt salts, nitrate-based nickel salts, nitrate-based manganese salts, ammonium molybdate, and stannous chloride. Another example is if M1 is 1 / 4M2, then the mass of multi-walled carbon nanotubes is equivalent to one-quarter of the total mass of the six nitrate-based iron salts, nitrate-based cobalt salts, nitrate-based nickel salts, nitrate-based manganese salts, ammonium molybdate, and stannous chloride. Yet another example is if M1 is 1 / 3M2, then the mass of multi-walled carbon nanotubes is equivalent to one-third of the total mass of the six nitrate-based iron salts, nitrate-based cobalt salts, nitrate-based nickel salts, nitrate-based manganese salts, ammonium molybdate, and stannous chloride.

[0026] Step 102: Dissolve the iron salt, cobalt salt, nickel salt, manganese salt, ammonium molybdate, and stannous chloride in the target solution to form an initial mixed solution.

[0027] The target solution can be in a container, and then nitric acid-based iron salts, nitric acid-based cobalt salts, nitric acid-based nickel salts, nitric acid-based manganese salts, ammonium molybdate, and stannous chloride can be added to the container containing the target solution. This allows the nitric acid-based iron salts, nitric acid-based cobalt salts, nitric acid-based nickel salts, nitric acid-based manganese salts, ammonium molybdate, and stannous chloride to dissolve in the target solution, thus forming an initial mixed solution.

[0028] In some implementations, step 102 can be implemented by dissolving nitric acid-based iron salts, nitric acid-based cobalt salts, nitric acid-based nickel salts, nitric acid-based manganese salts, ammonium molybdate, and stannous chloride in the target solution and then subjecting the solution to ultrasonic treatment to obtain an initial mixed solution.

[0029] In this process, nitric acid-based iron salts, nitric acid-based cobalt salts, nitric acid-based nickel salts, nitric acid-based manganese salts, ammonium molybdate, and stannous chloride are added to a container containing the target solution. Then, an ultrasonic wave is emitted into the container containing the target solution using a device capable of emitting ultrasonic waves. The ultrasonic waves pass through the target solution, allowing the nitric acid-based iron salts, nitric acid-based cobalt salts, nitric acid-based nickel salts, nitric acid-based manganese salts, ammonium molybdate, and stannous chloride in the target solution to dissolve relatively completely, thus obtaining the initial mixed solution.

[0030] It should be noted that, in the embodiments of this application, the target solution includes at least one of anhydrous ethanol and deionized water.

[0031] When the target solution includes anhydrous ethanol, this is equivalent to dissolving nitric acid-based iron salts, nitric acid-based cobalt salts, nitric acid-based nickel salts, nitric acid-based manganese salts, ammonium molybdate, and stannous chloride in anhydrous ethanol. For example, Fe(NO3)3·9H2O, Co(NO3)2·6H2O, Ni(NO3)2·6H2O, Mn(NO3)2·4H2O, and (NH4)6Mo7O 24 SnCl2 dissolves in anhydrous ethanol.

[0032] When the target solution includes deionized water, this is equivalent to dissolving nitric acid-based iron salts, nitric acid-based cobalt salts, nitric acid-based nickel salts, nitric acid-based manganese salts, ammonium molybdate, and stannous chloride in deionized water. For example, dissolving Fe(NO3)3·9H2O, Co(NO3)2·6H2O, Ni(NO3)2·6H2O, Mn(NO3)2·4H2O, and (NH4)6Mo7O in deionized water. 24 And SnCl2 dissolves in deionized water.

[0033] Step 103: Add multi-walled carbon nanotubes to the initial mixed solution to form an intermediate mixed solution.

[0034] Once an initial mixed solution is formed, multi-walled carbon nanotubes can be added to it to form an intermediate mixed solution. Specifically, when adding multi-walled carbon nanotubes to the initial mixed solution, the initial mixed solution can be stirred to ensure that the multi-walled carbon nanotubes are relatively uniformly dispersed in the initial mixed solution, thereby forming the intermediate mixed solution.

[0035] It should be noted that when stirring the initial mixed solution, the stirring time can be within a preset range, which can be 1 hour to 3 hours. For example, the stirring time is 1 hour, 2 hours, or 3 hours.

[0036] Step 104: Heat the intermediate mixture until all the liquid in the intermediate mixture evaporates to form the initial powder.

[0037] Once the intermediate mixed solution is obtained, it can be heated, causing the liquid in the intermediate mixed solution to evaporate. Continued heating will ensure complete evaporation of the liquid in the intermediate mixed solution until it is completely evaporated. The dissolved substances in the intermediate mixed solution will then remain as powder, thus obtaining the initial powder. The initial powder includes multi-walled carbon nanotubes, nitrate-based iron salts, nitrate-based cobalt salts, nitrate-based nickel salts, nitrate-based manganese salts, ammonium molybdate, and stannous chloride, among others.

[0038] In addition, in some implementations, heating the intermediate mixture until all the liquid in the intermediate mixture evaporates can be achieved by placing the intermediate mixture in a heating device, wherein the temperature in the heating device is within a first set temperature range, and heating the intermediate mixture until all the liquid in the intermediate mixture evaporates.

[0039] The intermediate mixture solution can be located in a container, that is, the container contains the intermediate mixture solution. The container containing the intermediate mixture solution can be placed in a heating device, which is equivalent to placing the intermediate mixture solution in the heating device. The temperature in the heating device is within a first set temperature range, so the heating device can heat the intermediate mixture solution, causing the liquid of the intermediate mixture solution to evaporate. Until the liquid of the intermediate mixture solution is completely evaporated, powder will remain in the container. The powder in the container can be collected to obtain the initial powder.

[0040] It should be noted that the first set temperature range can be 100℃-200℃. Of course, the first set temperature range can also be other temperature ranges, for example, 200℃-400℃. This application does not limit this aspect. It is only necessary to ensure that the liquid in the intermediate mixed solution can be evaporated.

[0041] In addition, the heating device can be an electric heating device, or it can be a tube furnace, etc. This application does not limit the specific implementation of the embodiments.

[0042] Step 105: Perform thermal shock on the initial powder to obtain a high-entropy alloy-based catalyst.

[0043] Once the initial powder is obtained, it can be thermally shocked, and the resulting powder becomes a high-entropy alloy-based catalyst. This catalyst contains a FeCoNiMnMoSn high-entropy alloy and Mo2C, with Mo2C obtained through a heating reaction. This means the catalyst possesses both FeCoNiMnMoSn and Mo2C as dual active sites, and the synergistic effect between these sites promotes both catalytic activity and stability, resulting in a catalyst with good catalytic activity and stability. Furthermore, the introduction of Sn can cause lattice distortion, thereby enhancing catalytic performance. Therefore, the resulting high-entropy alloy catalyst not only exhibits good catalytic activity and stability but also superior catalytic performance.

[0044] In addition, in some implementations, the initial powder can be subjected to thermal shock by placing the initial powder in a Joule thermal shock apparatus and subjecting the initial powder to thermal shock through the Joule thermal shock apparatus.

[0045] In the process of thermally shocking the initial powder, the initial powder can be placed in a Joule thermal shock device, that is, the initial powder is thermally shocked using the Joule thermal shock method, which is equivalent to instantaneously heating the initial powder at a high temperature, so that the initial powder forms a high-entropy alloy-based catalyst after being thermally shocked.

[0046] In addition, in some implementations, the initial powder is subjected to thermal shock by a Joule thermal shock device in such a way that the duration of thermal shock by the Joule thermal shock device is within a set duration range, and the shock temperature of the Joule thermal shock device is within a second set temperature range.

[0047] The set duration can be between 1s and 10s, and the set temperature can be between 700℃ and 900℃. That is, when the initial powder is subjected to thermal shock using the Joule thermal shock device, the duration of the shock can be any value between 1s and 10s, and the shock temperature can be any value between 700℃ and 900℃. For example, when the initial powder is subjected to thermal shock using the Joule thermal shock device, the shock duration is 1s and the shock temperature is 700℃; another example is that the shock duration is 5s and the shock temperature is 800℃; yet another example is that the shock duration is 10s and the shock temperature is 800℃.

[0048] In addition, when the initial powder is subjected to thermal shock by the Joule thermal shock device, the shock voltage of the Joule thermal shock device is 32 V and the shock current is 56 A.

[0049] The following is a comparative description of the performance of the high-entropy alloy-based catalysts prepared in the embodiments of this application: Specifically, high-entropy alloy-based catalysts can be prepared by using different amounts of these catalysts, and the results can be tested, as follows: Example 1: Fe(NO3)3·9H2O, Co(NO3)2·6H2O, Ni(NO3)2·6H2O, Mn(NO3)2·4H2O, and (NH4)6Mo7O were used. 24 A high-entropy alloy-based catalyst was prepared by dispersing SnCl2 in anhydrous ethanol at a molar ratio of 1:1:1:0.1:1.6:0.1 with SnCl2. Porous wall carbon nanotubes, with a total metal salt mass of 1 / 4, were also added and dispersed in the anhydrous ethanol solution. After uniform dispersion, the mixture was dried to obtain the initial powder. The initial powder was then subjected to Joule thermal shock at a controlled temperature (800℃), with an impact voltage of 32 V and an impact current of 56 A.

[0050] Example 2: Using the same method as Example 1, under the same conditions as Example 1, the difference is that Fe(NO3)3·9H2O, Co(NO3)2·6H2O, Ni(NO3)2·6H2O, Mn(NO3)2·4H2O, and (NH4)6Mo7O are used. 24 The molar ratio of SnCl2 to SnCl2 is 1:1:1:0.1:n:0.1, where n = 1.2, 1.4, and 1.8. This corresponds to a change in (NH4)6Mo7O in Example 2. 24 Dosage.

[0051] Example 3: Using the same method as Example 1, under the same conditions as Example 1, the difference is that Fe(NO3)3·9H2O, Co(NO3)2·6H2O, Ni(NO3)2·6H2O, Mn(NO3)2·4H2O, and (NH4)6Mo7O are used. 24 The molar ratio of SnCl2 to SnCl2 is 1:1:1:0.1:1.6:m, where m = 0, 0.05, and 0.15. In Example 3, this is equivalent to changing the amount of SnCl2 used.

[0052] The performance of the high-entropy alloy-based catalyst obtained in Example 1 was tested, specifically: Figure 2 This is the XRD pattern of the high-entropy alloy-based catalyst prepared by the method in Example 1. From... Figure 2 It can be seen that the high-entropy alloy-based catalyst contains a high-entropy alloy phase (HEA alloy phase) and a Mo2C phase, and both the high-entropy alloy phase and the Mo2C phase have high purity.

[0053] Figure 3This is a scanning electron microscope image of the high-entropy alloy-based catalyst prepared by the method in Example 1. Figure 3 As shown, the surface of the high-entropy alloy-based catalyst has a large number of linear carbon nanotube structures. They are intertwined to form a three-dimensional network structure with a large number of pores, which has a considerable surface area and is more conducive to the large exposure of active sites. Moreover, the nano-high-entropy alloy particles are uniformly distributed in the carbon nanotubes.

[0054] Figure 4 This is a transmission electron microscope image of the high-entropy alloy-based catalyst prepared by the method in Example 1. Figure 4 As can be seen, the nano-high entropy alloy is uniformly distributed in the carbon nanotubes.

[0055] Figure 5 This is an elemental distribution map of the high-entropy alloy-based catalyst prepared by the method in Example 1. Figure 5 As can be seen, the various metal elements are evenly distributed.

[0056] Figure 6 This is a polarization curve of the high-entropy alloy-based catalyst prepared by the method in Example 1 and a commercially available RuO2 catalyst in 1 M KOH solution for the electrocatalytic oxygen evolution reaction (OER). Figure 6 As shown, the OER polarization curve of the high-entropy alloy-based catalyst prepared in Example 1 is significantly better than that of the existing commercially available RuO2 catalyst, with an OER overpotential of 280 mV, exceeding that of RuO2 (320 mV).

[0057] Figure 7 The diagram shows the specific capacity of a zinc-air battery assembled using the high-entropy alloy-based catalyst prepared by the method in Example 1, which has a high specific capacity of 793.7 mA·h / gZn (the theoretical value is 820 mA·h / gZn).

[0058] Figure 8 This is a rate performance diagram of a zinc-air battery assembled using the high-entropy alloy-based catalyst prepared by the method in Example 1. Figure 8 It can be seen that the zinc-air battery assembled with the high-entropy alloy-based catalyst prepared by the method in Example 1 has excellent rate performance.

[0059] The high-entropy alloy-based catalyst prepared by the scheme in Example 2 was tested and compared with the high-entropy alloy-based catalyst prepared by the scheme in Example 1, as shown in Table 1: Table 1 Table 1 shows the overpotential tests performed on the three high-entropy alloy-based catalysts prepared by the scheme in Example 2 and the high-entropy alloy-based catalyst prepared by the scheme in Example 1. The CV tests were conducted at scan rates of 20, 40, 60, 80, and 100 Mv / s, selecting non-Radidatic potential ranges, and Cdl was calculated. Table 1 shows that, compared to Example 1, the scheme in Example 2, during the preparation of the high-entropy alloy-based catalyst, (NH4)6Mo7O 24 Near the optimal ratio, its overpotential (OER) performance is worse than that of the high-entropy alloy-based catalyst prepared by the scheme in Example 1.

[0060] The high-entropy alloy-based catalyst prepared by the scheme in Example 3 was tested and compared with the high-entropy alloy-based catalyst prepared by the scheme in Example 1, as shown in Table 2: Table 2 In Table 2, overpotential tests were performed on the three high-entropy alloy-based catalysts prepared by the scheme in Example 3 and the high-entropy alloy-based catalyst prepared by the scheme in Example 1. CV tests were conducted by selecting non-Radidatic potential ranges at scan rates of 20, 40, 60, 80, and 100 Mv / s, and Cdl was calculated. As can be seen from Table 1, compared with Example 1, the overpotential (OER) performance of the scheme in Example 3, with SnCl2 near the optimal ratio during the preparation of the high-entropy alloy-based catalyst, was worse than that of the high-entropy alloy-based catalyst prepared by the scheme in Example 1.

[0061] In addition, the high-entropy alloy-based catalyst prepared by the preparation method provided in this application can be subjected to electrochemical testing, i.e., electrocatalytic oxygen evolution. Specifically, the electrochemical tests are all performed in a standard three-electrode glass cell of a CHI 760F electrochemical workstation, with the electrolytic cell filled with 1 M KOH solution. A glassy carbon electrode (GCE) coated with catalyst, a graphite electrode, and an Ag / AgCl electrode are used as the working electrode, counter electrode, and reference electrode, respectively. 2.5 mg of high-entropy alloy-based catalyst and 10 µL of 5% Nafion solution are dispersed in 490 µL of ethanol solution to prepare the catalyst ink required for overpotential (OER) testing. The mixture is sonicated for 30 min to form a uniform ink. Subsequently, an equal volume of 10 µL of catalyst ink is transferred to a glassy carbon electrode (0.5 cm in diameter, 0.196 cm in diameter). 2 The surface was adjusted to allow the catalyst loading on the electrode to be 0.25 mg / cm². 2The catalyst was then completely dried in air. To establish a benchmark for overpotential performance (OER), the same electrode preparation and testing methods were used for commercially available RuO2 catalysts. The overpotential of the high-entropy alloy-based catalyst prepared in this application was 280 mV, exceeding the 320 mV of RuO2, as shown by LSV curves. CV tests were performed at scan rates of 20, 40, 60, 80, and 100 Mv / s to calculate Cdl.

[0062] In this embodiment, nitric acid-based iron salts, nitric acid-based cobalt salts, nitric acid-based nickel salts, nitric acid-based manganese salts, ammonium molybdate, stannous chloride, and multi-walled carbon nanotubes are provided. These nitric acid-based iron salts, cobalt salts, nickel salts, manganese salts, ammonium molybdate, and stannous chloride are dissolved in a target solution to form an initial mixed solution. Multi-walled carbon nanotubes are added to the initial mixed solution to form an intermediate mixed solution. The intermediate mixed solution is heated until all liquid in the intermediate mixed solution evaporates to form an initial powder. The initial powder is then subjected to thermal shock to obtain a high-entropy alloy-based catalyst. That is, in this embodiment, the prepared high-entropy alloy-based catalyst has FeCoNiMnMoSn high-entropy alloy and Mo2C, which is equivalent to the high-entropy alloy-based catalyst having FeCoNiMnMoSn high-entropy alloy and Mo2C as dual active sites. The synergistic effect between the dual active sites promotes the catalytic activity and stability, resulting in the high-entropy alloy catalyst exhibiting good catalytic activity and stability. In addition, the introduction of Sn can cause lattice distortion, thereby promoting the improvement of catalytic performance. This results in a high-entropy alloy catalyst that not only has good catalytic activity and stability, but also good catalytic performance.

[0063] This application provides a high-entropy alloy-based catalyst, which is prepared by the preparation method in any of the above embodiments. The high-entropy alloy catalyst includes iron, cobalt, nickel, manganese, molybdenum and tin.

[0064] This application provides a zinc-air battery that includes the high-entropy alloy-based catalyst described in the above embodiments.

[0065] It should be noted that, in the embodiments of this application, the anode of the zinc-air battery is a polished zinc sheet, and the cathode consists of an anti-dendritic membrane, carbon cloth coated with a high-entropy alloy-based catalyst, nickel foam, and an air diffusion layer. The loading of the high-entropy alloy-based catalyst is 1.0 mg / cm³. 2 The electrolyte is a mixed solution of 6 M KOH and 0.2 M Zn(CH3COO)2 prepared from ultrapure water.

[0066] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0067] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A method for preparing a high-entropy alloy-based catalyst, characterized in that, The preparation method of the high-entropy alloy-based catalyst includes: It provides nitrate-based iron salts, nitrate-based cobalt salts, nitrate-based nickel salts, nitrate-based manganese salts, ammonium molybdate, stannous chloride, and multi-walled carbon nanotubes; The iron salt, cobalt salt, nickel salt, manganese salt, ammonium molybdate, and stannous chloride of the nitrate system are dissolved in the target solution to form an initial mixed solution. The multi-walled carbon nanotubes are added to the initial mixed solution to form an intermediate mixed solution; The intermediate mixture is heated until all the liquid in the intermediate mixture evaporates to form the initial powder; The initial powder was subjected to thermal shock to obtain a high-entropy alloy-based catalyst.

2. The method for preparing the high-entropy alloy-based catalyst according to claim 1, characterized in that, The molar ratio of the nitric acid-based iron salt, the nitric acid-based cobalt salt, the nitric acid-based nickel salt, the nitric acid-based manganese salt, the ammonium molybdate, and the stannous chloride is 1: 1: 1: 0.1: x: y; Where 1.2≤x≤1.8, 0<y≤0.

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3. The method for preparing the high-entropy alloy-based catalyst according to claim 1, characterized in that, The mass of the multi-walled carbon nanotube is M1, and the sum of the masses of the six nitrate-based iron salt, nitrate-based cobalt salt, nitrate-based nickel salt, nitrate-based manganese salt, ammonium molybdate, and stannous chloride is M2, satisfying: 1 / 5M2≤M1≤1 / 3M2.

4. The method for preparing the high-entropy alloy-based catalyst according to claim 1, characterized in that, The target solution includes at least one of anhydrous ethanol and deionized water.

5. The method for preparing the high-entropy alloy-based catalyst according to claim 1, characterized in that, The nitric acid-based iron salt, the nitric acid-based cobalt salt, the nitric acid-based nickel salt, the nitric acid-based manganese salt, the ammonium molybdate, and the stannous chloride are dissolved in the target solution to form an initial mixed solution, comprising: The iron salt, cobalt salt, nickel salt, manganese salt, ammonium molybdate, and stannous chloride of the nitrate system are dissolved in the target solution and subjected to ultrasonic treatment to obtain the initial mixed solution.

6. The method for preparing the high-entropy alloy-based catalyst according to claim 1, characterized in that, Heating the intermediate mixture until all the liquid in the intermediate mixture has evaporated includes: The intermediate mixture is placed in a heating device, and the temperature in the heating device is within a first set temperature range. The intermediate mixture is heated by the heating device until all the liquid in the intermediate mixture evaporates.

7. The method for preparing the high-entropy alloy-based catalyst according to claim 1, characterized in that, The thermal shock treatment of the initial powder includes: The initial powder is placed in a Joule thermal shock apparatus and subjected to thermal shock by the Joule thermal shock apparatus.

8. The method for preparing the high-entropy alloy-based catalyst according to claim 7, characterized in that, The initial powder is subjected to thermal shock using the Joule thermal shock apparatus, including: The duration of thermal shock of the initial powder by the Joule thermal shock device is within a set duration range, and the impact temperature of the Joule thermal shock device is within a second set temperature range.

9. A high-entropy alloy-based catalyst, characterized in that, The high-entropy alloy-based catalyst is prepared by the preparation method according to any one of claims 1-8, and the high-entropy alloy catalyst includes iron, cobalt, nickel, manganese, molybdenum and tin.

10. A zinc-air battery, characterized in that, The zinc-air battery includes the high-entropy alloy-based catalyst as described in claim 9.

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