A cobalt-manganese oxide flexible electrode and its preparation and application

Abstract

The present invention belongs to the field of air electrode materials for zinc-air batteries, and discloses a cobalt manganese oxide flexible electrode and its preparation and application. The present invention first performs a hydrothermal reaction and then calcines in a muffle furnace to obtain a MnCo2O4 electrode with a nano-array structure, and then calcines it at high temperature under an Ar / H2 atmosphere to finally obtain a Co / MnOx electrode. The present invention obtains a Co / MnOx electrode through a simple hydrothermal reaction, an air calcination, and an Ar / H2 calcination. The operation is simple and efficient, saving a lot of time and raw material resources. The cobalt manganese oxide flexible electrode material has both mechanical flexibility and electrocatalytic activity. It is used as an air cathode for liquid and all-solid-state zinc-air batteries and has high cycle stability. After cycling, it exhibits good cycle stability, can provide an open circuit voltage of up to 1.524V in a liquid zinc-air battery, and can cycle stably for several hours.

Description

Technical Field

[0001] The present invention belongs to the field of zinc-air battery air electrode materials, and in particular relates to a cobalt manganese oxide flexible electrode and its preparation and application. Background Art

[0002] Zinc-air batteries offer advantages such as high energy density, safety, reliability, environmental friendliness, and low cost. Flexible, rechargeable zinc-air batteries are particularly promising as a next-generation power source for wearable devices, and their research and development has garnered widespread attention in recent years. The zinc metal in the negative electrode of zinc-air batteries is inexpensive and readily available, the discharge product, zinc oxide, is fully recyclable, and the air in the positive electrode is free and infinitely available, far lower than that of lithium-ion batteries. Zinc-air batteries also have a lower current density, making them more suitable for applications with high energy density and low power requirements, such as power supplies for hearing aids and emergency lighting.

[0003] Despite significant progress in flexible zinc-air batteries, they still face numerous bottlenecks. The first is to further enhance electrochemical performance (capacity, rate, battery cycle life, and efficiency). The second is to increase the actual energy density of zinc-air batteries. While zinc-air batteries possess a high theoretical energy density, the slow redox reaction within them significantly reduces performance (far below the theoretical energy density). Therefore, oxygen catalysts in the air electrode play a crucial role in enhancing the redox reaction rate and energy conversion efficiency. Oxygen catalysts primarily catalyze the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in the air electrode. ORR catalysts interact with oxygen in the air, promoting the reduction of oxygen to hydroxide, thereby achieving catalytic activity by accelerating electron transfer between the electrode and oxygen. However, the catalytic mechanism of OER is completely opposite to that of ORR, making it difficult to obtain catalysts that are sufficiently active for both OER and ORR. Currently, mainstream commercial noble metal oxygen catalysts can only catalyze one of the OER / ORR reactions. For example, Pt-based oxidants primarily catalyze the ORR reaction, while Ru and its oxides catalyze the OER reaction. However, traditional noble metal oxygen catalysts have problems such as high cost and limited reserve resources. Therefore, it is necessary to develop new OER / ORR bifunctional oxygen catalysts to improve the catalytic activity of the electrode.

[0004] Compared to precious metals, transition metals offer advantages such as low cost, high reserves, and environmental friendliness. Transition metals have a variety of valence states and can form a variety of oxides with different crystal structures. Their electrocatalytic activity can be enhanced by adjusting their morphology, structure, and chemical composition. Strategies such as doping transition metals with heteroatoms or carbon composites can be used to increase the number of catalytically active sites in the material, thereby enhancing the bifunctional catalytic activity of the catalyst. This effectively improves the charge-discharge reaction rate and cycling stability in flexible zinc-air batteries, reduces the battery overpotential, and ultimately produces flexible zinc-air batteries with high specific energy density and excellent cycling performance. Summary of the Invention

[0005] In order to overcome the above-mentioned shortcomings and deficiencies of the prior art, the primary purpose of the present invention is to provide a method for preparing a cobalt manganese oxide flexible electrode material.

[0006] Another object of the present invention is to provide a cobalt manganese oxide flexible electrode material prepared by the above method.

[0007] Another object of the present invention is to provide an application of the above-mentioned cobalt manganese oxide flexible electrode material in zinc-air batteries.

[0008] The purpose of the present invention is achieved through the following solutions:

[0009] A method for preparing a cobalt manganese oxide flexible electrode material comprises the following steps:

[0010] (1) dissolving urea, ammonium fluoride, a soluble cobalt salt, and a soluble manganese salt in water, stirring uniformly to form a mixed solution, adding the mixed solution to a reactor, suspending a conductive substrate in the mixed solution, and performing a hydrothermal reaction. After the reaction is completed, taking out the conductive substrate, washing it with water and anhydrous ethanol, drying it, and placing it in a muffle furnace for calcining in air to obtain a product of MnCo2O4 / conductive substrate;

[0011] (2) The MnCo2O4 / conductive substrate is placed in a tube furnace and calcined in an Ar / H2 atmosphere to obtain a Co / MnOx electrode, i.e., a cobalt manganese oxide flexible electrode material.

[0012] The soluble manganese salt and the soluble cobalt salt described in step (1) are relatively independently at least one of nitrate, sulfate, and acetate;

[0013] The mass ratio of the soluble manganese salt to the soluble cobalt salt described in step (1) is 1:3-3.5, the mass ratio of the total mass of the soluble manganese salt and the soluble cobalt salt to urea is 2-2.5:1, and the mass ratio of the total mass of the soluble manganese salt and the soluble cobalt salt to ammonium fluoride is 4-4.5:1.

[0014] The amount of water used in step (1) satisfies: the mass concentration of soluble manganese salt in the mixed solution is 0.5-1g / L. The area of ​​the conductive substrate described in step (1) satisfies: one piece of 2*2.5cm conductive substrate is added to every 30-40mL of the mixed solution.

[0015] The stirring time for uniformly forming the mixed solution in step (1) is preferably 0.5 to 1 hour.

[0016] The hydrothermal reaction in step (1) is carried out at 90 to 110° C. for 6 to 10 hours.

[0017] The cleaning described in step (1) refers to repeated cleaning with water and anhydrous ethanol in sequence until there is no free precipitate on the surface of the sample; the drying described in step (1) refers to drying at 40-80° C. for 2-6 hours.

[0018] The calcination described in step (1) refers to calcination at 400° C. for 1 hour.

[0019] The volume percentage of H2 in the Ar / H2 atmosphere described in step (2) is 8%.

[0020] The calcination in step (2) refers to calcination at 300-450° C. for 1-3 hours.

[0021] A cobalt manganese oxide flexible electrode material prepared by the above method.

[0022] The aforementioned cobalt-manganese oxide flexible electrode material is used in zinc-air batteries. This cobalt-manganese oxide flexible electrode material combines mechanical flexibility with electrocatalytic activity. It is used as the air cathode in liquid and all-solid-state zinc-air batteries and exhibits high cycling stability. After cycling, it exhibits excellent cycling stability, providing an open-circuit voltage of up to 1.524V in liquid zinc-air batteries and maintaining stable cycling for several hours.

[0023] The present invention first conducts a hydrothermal reaction followed by calcination in a muffle furnace to produce a MnCo2O4 electrode with a nanoarray structure. This is then followed by high-temperature calcination in an Ar / H2 atmosphere to ultimately produce a Co / MnOx electrode. This method achieves the Co / MnOx electrode through a simple hydrothermal reaction, followed by air calcination and Ar / H2 calcination. The process is simple and efficient, saving significant time and raw material resources.

[0024] The cobalt-manganese nanostructured array, grown on a conductive substrate via a hydrothermal reaction, has an overall appearance resembling velvety needles and grows horizontally along the nickel foam, forming a dense array. The interlaced nanostructures create a porous structure, increasing the specific surface area of ​​the Co / MnOx. These pores facilitate electrolyte penetration and oxygen diffusion, thereby enhancing the kinetics of the oxygen catalytic reaction and increasing the number of surface active sites, thereby increasing the electrode's electrochemical catalytic effect and enhancing its bifunctional oxygen catalytic activity.

[0025] The cobalt manganese oxide flexible electrode of the present invention utilizes its three-dimensional self-supporting structure to form a porous network morphology, thereby promoting electrolyte penetration and oxygen diffusion. By combining transition metal diatomic complexes, the catalyst active sites are increased, and the staggered arrangement of linear nanoarrays further increases the electrode active surface area, resulting in a flexible electrode with efficient OER / ORR dual-functional catalytic activity.

[0026] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0027] (1) The cobalt manganese oxide flexible electrode material prepared by the present invention has high electrochemical activity and good cycle performance, and has good application development prospects.

[0028] (2) The cobalt manganese oxide flexible electrode material prepared by the method of the present invention has stable oxygen catalysis and oxygen reduction catalysis performance.

[0029] (3) The present invention adopts hydrothermal reaction synthesis technology, which is simple to operate, easy to control reaction conditions, strong operability, high repeatability, and can be widely used in industrialization. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a scanning electron microscope (SEM) image of the Co / MnOx electrode obtained in Example 1.

[0031] Figure 2 These are the OER performance diagrams and ORR performance diagrams of the Co / MnOx electrodes prepared in Example 1 and Example 2 under different reduction reaction temperatures in a three-electrode system.

[0032] Figure 3 These are the OER performance diagrams and ORR performance diagrams of the Co / MnOx electrodes prepared in Example 1 and Example 3 under different reduction reaction times in a three-electrode system.

[0033] Figure 4 These are the OER performance diagrams and ORR performance diagrams of the Co / MnOx electrodes prepared in Example 1 and Example 4 under different hydrothermal reaction temperatures in a three-electrode system.

[0034] Figure 5These are the OER performance diagrams and ORR performance diagrams of the Co / MnOx electrodes prepared in Example 1 and Example 5 under the three-electrode system at different hydrothermal reaction times.

[0035] Figure 6 The OER performance diagram and ORR performance diagram comparing the Co / MnOx electrode and the MnCo2O4 electrode obtained in Example 1.

[0036] Figure 7 2 is the XRD pattern of the Co / MnOx electrode prepared in Example 1 under the three-electrode system.

[0037] Figure 8 This is a cycle performance diagram of the Co / MnOx electrode obtained in Example 1 used as the air cathode of a liquid zinc-air battery in a constant current charge and discharge test.

[0038] Figure 9 This is an open circuit voltage diagram of the constant current charge and discharge test of the Co / MnOx electrode obtained in Example 1 as the air cathode of a liquid zinc-air battery.

[0039] Figure 10 This is a power density diagram of the constant current charge and discharge test of the Co / MnOx electrode obtained in Example 1 as the air cathode of a liquid zinc-air battery. DETAILED DESCRIPTION

[0040] The present invention will be described in further detail below with reference to the Examples and accompanying drawings, but the embodiments of the present invention are not limited thereto. Where specific conditions are not specified in the Examples, conventional conditions or conditions recommended by the manufacturer were followed. Reagents or instruments used, where the manufacturer is not specified, are commercially available conventional products.

[0041] The voltage (potential) values ​​described in the examples are all expressed with reference to the reversible hydrogen electrode (RHE).

[0042] Example 1

[0043] The present embodiment provides a method for preparing a cobalt manganese oxide flexible electrode material, and the specific preparation steps are as follows:

[0044] (1) Preparation of Co / MnOx electrode: 0.36g urea, 0.19g ammonium fluoride, 0.58g cobalt nitrate hexahydrate and 0.18g manganese nitrate were dissolved in deionized water and stirred to form a mixture. The concentration of manganese nitrate in the mixture was 0.9g / L. A portion of the mixture was taken into a reactor, and the pretreated 2*2.5cm nickel foam was suspended in 35ml of the mixture. The mixture was subjected to a hydrothermal reaction at 110°C for 6 hours. After the reaction, the nickel foam was removed, washed with deionized water and anhydrous ethanol, dried, and placed in a muffle furnace and heated to 400°C at 5°C / min and calcined in air for 1 hour to obtain the product MnCo2O4 / NF. Subsequently, the MnCo2O4 / NF was placed in a tube furnace and calcined at 450°C for 3 hours in an Ar / H2 atmosphere (H2 volume percentage 8%) to obtain a Co / MnOx electrode.

[0045] (2) At room temperature, the standard three-electrode system was used for testing on an electrochemical workstation. The synthesized Co / MnOx electrode (effective area 1*1cm 2 ) as the working electrode, platinum sheet (2*2cm 2 ) was used as the counter electrode and the Ag / AgCl electrode was used as the reference electrode. The OER and ORR performances of the Co / MnOx electrode were tested in 1 M KOH solution and 0.1 M KOH solution, respectively.

[0046] (3) The NEWARE battery testing system was used to test the charge and discharge performance (cycle performance, open circuit voltage, power density, etc.) of the battery (the battery was assembled using a traditional mold, the electrolyte was a mixture of 6M KOH and 0.2M zinc acetate, and the Co / MnOx electrode and zinc sheet were used as the cathode and anode of the zinc-air battery, respectively).

[0047] The SEM image of the Co / MnOx electrode obtained in Example 1 is as follows: Figure 1 As shown. Figure 1 The nanostructure of the electrode can be seen in the figure. The Co / MnOx grown on the nickel foam is in the shape of velvety nanowires, and the nanowires are closely arranged to form a porous structure.

[0048] Figure 6 The OER performance diagram of the Co / MnOx electrode and the MnCo2O4 electrode obtained in Example 1 is compared ( Figure 6 a) and ORR performance diagram ( Figure 6 b) in Figure 6 It can be seen that the Co / MnOx electrode after two heat treatments is 2At this current density, the corresponding potential is only 1.51 V, demonstrating superior OER performance compared to the single-heat-treated MnCo2O4 electrode. Furthermore, the Co / MnOx electrode exhibits an excellent half-wave potential (approximately 0.8 V), significantly higher than the MnCo2O4 electrode (approximately 0.61 V).

[0049] Figure 7 This is the XRD pattern of the Co / MnOx electrode prepared in Example 1. As can be seen from the figure, Co / MnOx has multiple diffraction peaks, which are consistent with the standard peaks of spinel Co, MnO2 and MnO. It can be seen that the electrode has high purity and good crystal structure.

[0050] The battery performance of Co / MnOx-based liquid zinc-air batteries was tested using the NEWARE battery testing system. Figure 8 This is a cycling performance diagram of the Co / MnOx electrode obtained in Example 1 as the air cathode of a liquid zinc-air battery undergoing a constant current discharge test. After 360 hours of cycling, the charge and discharge potential difference is 0.952 V, indicating that the Co / MnOx electrode as the air cathode of the zinc-air battery achieves excellent battery performance and high cycling stability. Figure 9 This is an open circuit voltage diagram of the constant current discharge test of the Co / MnOx electrode obtained in Example 1 as the air cathode of the liquid zinc-air battery. The open circuit voltage of the Co / MnOx-based liquid zinc-air battery is 1.524V. Figure 10 The power density diagram of the Co / MnOx electrode obtained in Example 1 as the air cathode of the liquid zinc-air battery in a constant current discharge test is shown. Co / MnOx achieves a power density of up to 111.37 mW cm -2 The power density of Co / MnOx electrode is shown to be excellent as the air cathode of Zn-air battery.

[0051] Example 2

[0052] The present embodiment provides a method for preparing a cobalt manganese oxide flexible electrode material, and the specific preparation steps are as follows:

[0053] (1) Preparation of Co / MnOx electrode: 0.36g urea, 0.19g ammonium fluoride, 0.58g cobalt nitrate hexahydrate and 0.18g manganese nitrate were dissolved in deionized water and stirred to form a mixed solution. The concentration of manganese nitrate in the mixed solution was 0.9g / L. A portion of the mixed solution was taken into a reactor, and the pretreated 2*2.5cm nickel foam was suspended in 35ml of the mixed solution. The mixture was subjected to a hydrothermal reaction at 90°C for 6 hours. After the reaction, the nickel foam was removed, washed with deionized water and anhydrous ethanol, dried, and placed in air calcined at a temperature of 5°C / min to 400°C for 1 hour to obtain the product MnCo2O4 / NF. Subsequently, the MnCo2O4 / NF was placed in a tube furnace and calcined at 450°C for 3 hours in an Ar / H2 atmosphere (H2 volume percentage 8%) to obtain a Co / MnOx electrode.

[0054] (2) At room temperature, the standard three-electrode system was used for testing on an electrochemical workstation. The synthesized Co / MnOx electrode (effective area 1*1cm 2 ) as the working electrode, platinum sheet (2*2cm 2 ) was used as the counter electrode and the Ag / AgCl electrode was used as the reference electrode. The OER and ORR performances of the Co / MnOx electrode were tested in 1 M KOH solution and 0.1 M KOH solution, respectively.

[0055] Figure 2 The OER performance diagram of the Co / MnOx electrode prepared in Example 1 under the three-electrode system ( Figure 2 a) and ORR performance diagram ( Figure 2 As can be seen from the figure, when the hydrothermal reaction temperature is 110 °C, the OER performance of the MnCoOx electrode is the best. -2 When the hydrothermal reaction temperature is 110℃, the corresponding potential is only 1.52V, showing its excellent OER performance; when the hydrothermal reaction temperature is 110℃, Co / MnOx has a higher half-wave potential (about 0.79V), showing good ORR performance.

[0056] Example 3

[0057] The present embodiment provides a method for preparing a cobalt manganese oxide-based flexible electrode material, and the specific preparation steps are as follows:

[0058] (1) Preparation of Co / MnOx electrode: 0.36g urea, 0.19g ammonium fluoride, 0.58g cobalt nitrate hexahydrate and 0.18g manganese nitrate were dissolved in deionized water and stirred to form a mixed solution. The concentration of manganese nitrate in the mixed solution was 0.9g / L. A portion of the mixed solution was taken into a reactor, and the pretreated 2*2.5cm nickel foam was suspended in 35ml of the mixed solution. The mixture was subjected to a hydrothermal reaction at 110°C for 10 hours. After the reaction, the nickel foam was removed, washed with deionized water and anhydrous ethanol, dried, and placed in a muffle furnace and heated to 400°C at a rate of 5°C / min and calcined in air for 1 hour to obtain the product MnCo2O4 / NF. Subsequently, the MnCo2O4 / NF was placed in a tube furnace and calcined at 450°C for 3 hours in an Ar / H2 atmosphere (H2 volume percentage 8%) to obtain a Co / MnOx electrode.

[0059] (2) At room temperature, the standard three-electrode system was used for testing on an electrochemical workstation. The synthesized Co / MnOx electrode (effective area 1*1cm 2 ) as the working electrode, platinum sheet (2*2cm 2 ) was used as the counter electrode and the Ag / AgCl electrode was used as the reference electrode. The OER and ORR performances of the Co / MnOx electrode were tested in 1 M KOH solution and 0.1 M KOH solution, respectively.

[0060] Figure 3 is the OER of Example 3 under the three-electrode system ( Figure 3 a) Performance graph and ORR( Figure 3 b) Performance diagram. It can be seen from the figure that the OER performance of Co / MnOx is optimal at 6 hours. -2 When the hydrothermal reaction time was 10 h, the corresponding potential was only 1.46 V, demonstrating its excellent OER performance. The ORR performance of Co / MnOx showed a higher half-wave potential of about 0.80 V when the hydrothermal reaction time was 10 h.

[0061] Example 4

[0062] The present embodiment provides a method for preparing a cobalt manganese oxide-based flexible electrode material, and the specific preparation steps are as follows:

[0063] (1) Preparation of Co / MnOx electrode: 0.36g urea, 0.19g ammonium fluoride, 0.58g cobalt nitrate hexahydrate and 0.18g manganese nitrate were dissolved in deionized water and stirred to form a mixed solution. The concentration of manganese nitrate in the mixed solution was 0.9g / L. A portion of the mixed solution was taken into a reactor, and the pretreated 2*2.5cm nickel foam was suspended in 35ml of the mixed solution. The mixture was subjected to a hydrothermal reaction at 110°C for 6 hours. After the reaction, the nickel foam was removed, washed with deionized water and anhydrous ethanol, dried, and placed in a muffle furnace and heated to 400°C at 5°C / min and calcined in air for 1 hour to obtain the product MnCo2O4 / NF. Subsequently, the MnCo2O4 / NF was placed in a tube furnace and calcined at 300°C for 3 hours in an Ar / H2 atmosphere (H2 volume percentage 8%) to obtain a Co / MnOx electrode.

[0064] (2) At room temperature, the standard three-electrode system was used for testing on an electrochemical workstation. The synthesized Co / MnOx electrode (effective area 1*1cm 2 ) as the working electrode, platinum sheet (2*2cm 2 ) was used as the counter electrode and the Ag / AgCl electrode was used as the reference electrode. The OER and ORR performances of the Co / MnOx electrode were tested in 1 M KOH solution and 0.1 M KOH solution, respectively.

[0065] Figure 4 The OER performance diagram of Example 4 in the three-electrode system ( Figure 4 a) and ORR( Figure 4 b) Performance diagram. It can be seen from the figure that when the reduction temperature is 300℃, the Co / MnOx electrode shows excellent electrochemical performance. -2 When the potential is 1.48V, the corresponding potential is only 1.48V. In the ORR performance test, Co / MnOx shows a half-wave potential of about 0.76V.

[0066] Example 5

[0067] The present embodiment provides a method for preparing a cobalt manganese oxide-based flexible electrode material, and the specific preparation steps are as follows:

[0068] (1) Preparation of Co / MnOx electrode: 0.36g urea, 0.19g ammonium fluoride, 0.58g cobalt nitrate hexahydrate and 0.18g manganese nitrate were dissolved in deionized water and stirred to form a mixture. The concentration of manganese nitrate in the mixture was 0.9g / L. A portion of the mixture was placed in a reactor, and the pretreated 2*2.5cm nickel foam was suspended in 35ml of the mixture. A hydrothermal reaction was carried out at 110°C for 6 hours. After the reaction was completed, the nickel foam was removed, washed with deionized water and anhydrous ethanol, dried, placed in a muffle furnace, heated to 400°C at 5°C / min, and calcined in air for 1 hour to obtain the product MnCo2O4 / NF. Subsequently, the MnCo2O4 / NF was placed in a tube furnace and calcined at 450°C for 1 hour in an Ar / H2 atmosphere (H2 volume percentage 8%) to obtain a Co / MnOx electrode.

[0069] (2) At room temperature, the standard three-electrode system was used for testing on an electrochemical workstation. The synthesized Co / MnOx electrode (effective area 1*1cm 2 ) as the working electrode, platinum sheet (2*2cm 2 ) was used as the counter electrode and the Ag / AgCl electrode was used as the reference electrode. The OER and ORR performances of the Co / MnOx electrode were tested in 1 M KOH solution and 0.1 M KOH solution, respectively.

[0070] Figure 5 The OER performance diagram of the Co / MnOx electrode prepared in Example 5 under the three-electrode system ( Figure 5 a) and ORR performance diagram ( Figure 5 As can be seen from the figure b), there is no obvious difference in OER performance at different times; the ORR performance shows a higher half-wave potential (0.79V) when the reduction time is 3h, which reflects good ORR electrochemical activity.

[0071] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A method for preparing a cobalt manganese oxide flexible electrode material for the air cathode of a zinc-air battery, characterized in that The following steps are involved: (1) Dissolve urea, ammonium fluoride, soluble cobalt salt, and soluble manganese salt in water, stir evenly to form a mixed solution, add the mixed solution into a reactor, suspend the conductive substrate in the mixed solution, and perform a hydrothermal reaction. After the reaction is completed, remove the conductive substrate, wash it with water and anhydrous ethanol, dry it, and place it in a muffle furnace for calcination in air to obtain a product of MnCo2O4 / conductive substrate; (2) placing the MnCo2O4 / conductive substrate in a tube furnace and calcining it in an Ar / H2 atmosphere to obtain a Co / MnOx electrode, i.e., a cobalt manganese oxide flexible electrode material; The volume percentage of H2 in the Ar / H2 atmosphere described in step (2) is 8%; The calcination in step (2) refers to calcination at 300-450°C for 1-3 hours.

2. The method for preparing the cobalt manganese oxide flexible electrode material for the air cathode of a zinc-air battery according to claim 1, characterized in that: The soluble manganese salt and the soluble cobalt salt described in step (1) are relatively independently at least one of nitrate, sulfate and acetate.

3. The method for preparing the cobalt manganese oxide flexible electrode material for the air cathode of a zinc-air battery according to claim 1, characterized in that: The mass ratio of the soluble manganese salt to the soluble cobalt salt described in step (1) is 1:3~3.5, the mass ratio of the total mass of the soluble manganese salt and the soluble cobalt salt to urea is 2~2.5:1, and the mass ratio of the total mass of the soluble manganese salt and the soluble cobalt salt to ammonium fluoride is 4~4.5:

1.

4. The method for preparing the cobalt manganese oxide flexible electrode material for the air cathode of a zinc-air battery according to claim 1, characterized in that: The amount of water used in step (1) satisfies the following conditions: the mass concentration of soluble manganese salt in the mixed solution is 0.5-1 g / L; the conductive substrate used in step (1) satisfies the following conditions: a 2*2.5 cm conductive substrate is added to every 30-40 mL of the mixed solution.

5. The method for preparing the cobalt manganese oxide flexible electrode material for the air cathode of a zinc-air battery according to claim 1, characterized in that: The hydrothermal reaction in step (1) is carried out at 90-110°C for 6-10 hours.

6. The method for preparing the cobalt manganese oxide flexible electrode material for the air cathode of a zinc-air battery according to claim 1, characterized in that: The calcination in step (1) refers to calcination at 400°C for 1 hour.

7. A cobalt manganese oxide flexible electrode material for the air cathode of a zinc-air battery prepared according to the method according to any one of claims 1 to 6.

8. Use of the cobalt manganese oxide flexible electrode material for the air cathode of a zinc-air battery according to claim 7 in a zinc-air battery.

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