Bionic cocklebur fruit-shaped Mo modified Na2Mn8O16 nano material and preparation method thereof

Abstract

The invention discloses a bionic cocklebur fruit-shaped Mo modified Na2Mn8O16 nano material and a preparation method thereof, and belongs to the field of inorganic nano materials. The preparation method comprises the following steps: dissolving sodium molybdate dihydrate, potassium permanganate and urea in deionized water, and carrying out hydrothermal reaction, filtering, drying and calcining treatment to obtain a target product. The material presents a unique bionic multi-thorn structure in microstructure, the surface is provided with densely distributed burr-shaped protrusions, the length of the protrusions is about 30-50 nm, and the protrusions are radially arranged to form an open system with a high specific surface area. Through Mo modification and synergetic thorn morphology, the permeability of the electrolyte and the zinc ion migration rate are remarkably enhanced, and the conductivity and the structural stability of the material are effectively improved, so that the material shows excellent electrochemical performance. The process is simple, and the prepared material has a good application prospect in the field of zinc ion battery positive electrodes.

Description

Technical Field

[0001] This invention discloses biomimetic burdock-like Mo-modified Na2Mn8O 16 Nanomaterials and their preparation methods belong to the field of aqueous zinc-ion battery technology in inorganic materials. Background Technology

[0002] Against the backdrop of accelerated global energy structure transformation and the continued advancement of large-scale renewable energy applications, the development of efficient, safe, and low-cost energy storage technologies has become a research hotspot in the energy field. Among various energy storage systems, aqueous zinc-ion batteries show broad application prospects due to their safety, environmental friendliness, and abundant natural resources. However, this type of battery still faces the key challenge of insufficient cathode material performance in its commercialization process. Among these, manganese-based oxide materials are considered one of the most promising cathode material candidates due to their advantages such as high operating voltage, multi-electron reaction characteristics, and abundant resources.

[0003] Among various manganese-based oxides, sodium manganese oxides have attracted widespread attention due to their unique crystal structure, high theoretical capacity, and good structural stability. Their crystal structure, based on [MnO6] octahedral units, not only provides an ideal transport channel for zinc ion insertion and extraction but also effectively buffers volume changes during charge and discharge. However, sodium manganese oxide materials still suffer from poor conductivity, manganese dissolution, and slow interfacial reaction kinetics. During repeated sodium ion insertion and extraction, the material is prone to structural collapse, leading to capacity decay and decreased cycle stability. This is mainly attributed to the Jahn-Teller effect induced by the redox reaction of Mn ions. These problems severely restrict further improvements in their electrochemical performance.

[0004] In recent years, modifying electrode materials with transition metal elements has proven to be an effective strategy for improving their electrochemical performance. Among them, molybdenum (Mo) exhibits unique advantages in controlling the electronic structure and crystal morphology of materials due to its abundant valence states and large ionic radius. Introducing Mo... 6+ Electron doping can not only improve the intrinsic conductivity of materials but also induce lattice strain, thereby optimizing ion transport pathways. Therefore, developing a novel sodium-manganese oxide cathode material that can effectively suppress manganese dissolution and improve stability through elemental doping, while also providing abundant reactive sites through unique microstructure design to alleviate volume strain and promote ion transport, is of great significance for advancing aqueous zinc-ion battery technology. Inspired by the surface structure of burdock in nature, designing nanomaterials with biomimetic spiky structures is expected to significantly increase the electrode-electrolyte interface, enhance zinc ion storage capacity, and improve the structural stability of the material through its unique morphology. Summary of the Invention

[0005] To overcome the technical shortcomings of sodium manganese oxide in zinc-ion battery applications, this invention provides a biomimetic burdock-like Mo-modified Na2Mn8O 16 Nanomaterials and their preparation methods belong to the field of inorganic materials. Sodium molybdate dihydrate, potassium permanganate, and urea were dissolved in deionized water, followed by hydrothermal reaction, filtration, drying, and calcination to obtain biomimetic burdock-like Mo-modified Na₂Mn₈O₃. 16 Nanomaterials. This invention improves the electrochemical performance of nanomaterials through a one-step hydrothermal method and observes a biomimetic multi-spiky structure at the microscopic level. The synthesis method is simple, low-cost, and suitable for large-scale industrial production.

[0006] The biomimetic burdock-like Mo-modified Na2Mn8O of this invention 16 The nanomaterial exhibits characteristic diffraction peaks in its XRD pattern at 2θ angles of 12.52°, 18.46°, 28.31°, and 37.18°. In its XPS spectrum, the binding energies of Mo 3d orbitals are 231.49 eV and 234.65 eV, O 1s orbitals are 529.15 eV and 530.59 eV, Mn 2p orbitals are 641.47 eV and 653.37 eV, and Na 1s orbitals are 1070.71 eV. Mo has a +6 valence, while Mn exhibits both +3 and +4 valences.

[0007] This invention also provides biomimetic burdock-like Mo-modified Na2Mn8O 16 The preparation method of nanomaterials includes the following steps:

[0008] The first step is to disperse sodium molybdate dihydrate in deionized water, then add potassium permanganate and urea in sequence, and stir until the mixture is homogeneous.

[0009] The second step is to transfer the resulting mixed solution to a hydrothermal reactor, place it in an oven for constant temperature reaction, and allow it to cool naturally to room temperature after the reaction is complete.

[0010] The third step is to remove the reaction product, wash and filter it, and then dry it in an oven.

[0011] The fourth step involves calcining the dried product in a muffle furnace under air atmosphere, followed by cooling to obtain the biomimetic burdock-like Mo-modified Na2Mn8O. 16 Nanomaterials.

[0012] Furthermore, in the above technical solution, in the first step, the molar ratio of sodium molybdate dihydrate to potassium permanganate is 1:1.

[0013] Furthermore, in the above technical solution, in the first step, the molar ratio of urea to sodium molybdate dihydrate is 3:1.

[0014] Furthermore, in the above technical solution, in the second step, the temperature of the isothermal reaction is 160℃, and the reaction time is 6 hours.

[0015] Furthermore, in the above technical solution, in the third step, the reaction product is washed with pure water. Specifically, the product is placed in pure water to form a suspension, ultrasonically treated for 3 minutes, and then filtered. This washing process is repeated a total of 5 times.

[0016] Furthermore, in the above technical solution, in the third step, the drying temperature is 85℃ and the drying time is 1 hour.

[0017] Furthermore, in the above technical solution, in the fourth step, the calcination temperature is 450℃ and the constant temperature calcination time is 5 hours; wherein, the time to heat up to 450℃ is 2 hours, and the time to naturally cool down to below 200℃ after calcination is 2 hours.

[0018] The present invention also provides the above-mentioned biomimetic burdock-like Mo-modified Na2Mn8O 16 Application of nanomaterials in the cathode of aqueous zinc-ion batteries.

[0019] Beneficial effects of the invention:

[0020] 1. This invention prepares biomimetic burdock-like Mo-modified Na2Mn8O 16 Nanomaterials. The raw materials used are inexpensive and readily available, the synthesis methods are simple, and the preparation process is environmentally friendly with minimal pollution.

[0021] 2. This method constructs Na2Mn8O with a biomimetic cocklebur-like microstructure through Mo modification. 16 Nanomaterials. The surface of this material exhibits densely distributed radial, spiky protrusions, with protrusion lengths ranging from approximately 30 to 50 nm, forming an open structure with a high specific surface area. The synergistic effect of Mo modification and the spiky morphology not only significantly enhances the permeability of the electrolyte and the migration rate of zinc ions, but also effectively improves the conductivity and structural stability of the material, thus enabling it to exhibit excellent electrochemical performance.

[0022] 3. The process of this invention is simple and has good repeatability, and the prepared material has good application prospects in the field of zinc-ion battery cathode. Attached Figure Description

[0023] Figure 1 Na2Mn8O modified with biomimetic cocklebur-like Mo in Example 2 16 XRD patterns of nanomaterials;

[0024] Figure 2 Na2Mn8O modified with biomimetic cocklebur-like Mo in Example 216 SEM images of nanomaterials;

[0025] Figure 3 Na2Mn8O modified with biomimetic cocklebur-like Mo in Example 2 16 XPS spectra of nanomaterials; where: (a) is the full XPS spectrum; (b) is the XPS spectrum of Mo3d; (c) is the XPS spectrum of Na1s; (d) is the XPS spectrum of Mn2p; (e) is the XPS spectrum of O1s.

[0026] Figure 4 Na2Mn8O modified with biomimetic cocklebur-like Mo in Example 2 16 EDS plot of nanomaterials;

[0027] Figure 5 Na2Mn8O modified with biomimetic cocklebur-like Mo in Example 2 16 Elemental distribution diagrams of nanomaterials; where: (a) is the Mn elemental distribution diagram; (b) is the O elemental distribution diagram; (c) is the Na elemental distribution diagram; (d) is the Mo elemental distribution diagram;

[0028] Figure 6 Na2Mn8O modified with biomimetic cocklebur-like Mo in Example 2 16 Infrared spectrum of nanomaterials;

[0029] Figure 7 Na2Mn8O modified with biomimetic cocklebur-like Mo in Example 2 16 Raman spectra of nanomaterials;

[0030] Figure 8 Na2Mn8O modified with biomimetic burdock-like Mo as described in Example 5 16 Cyclic charge-discharge diagram of nanomaterials;

[0031] Figure 9 Na2Mn8O modified with biomimetic burdock-like Mo as described in Example 5 16 Cyclic voltammograms of nanomaterials;

[0032] Figure 10 Na2Mn8O modified with biomimetic burdock-like Mo as described in Example 5 16 AC impedance diagram of nanomaterials. Detailed Implementation

[0033] The present invention is further described below through specific examples. However, these examples are merely exemplary and are not limited to the scope of protection of the present invention; they are merely embodiments.

[0034] In the following embodiments, unless otherwise specified, the reagents, materials and instruments used are all conventional reagents, materials and instruments, and are commercially available. The reagents involved can also be synthesized by conventional synthesis methods.

[0035] Example 1

[0036] The first step is to disperse 4.3551g of sodium molybdate dihydrate in 60mL of deionized water and stir for 0.5 hours.

[0037] The second step is to add 3.7927g of potassium permanganate and 4.3243g of urea to the solution and continue stirring for 1 hour.

[0038] The third step is to transfer the resulting mixed solution to a hydrothermal reactor, place it in an oven, and react it at a constant temperature of 160 °C for 6 hours, and then allow it to cool naturally to room temperature.

[0039] The fourth step is to remove the reaction product from the hydrothermal reactor and perform a cleaning operation. The reaction product is placed in pure water to form a suspension, and then ultrasonically cleaned for 3 minutes in an ultrasonic cleaner. The suspension is then filtered, and the process is repeated a total of 5 times.

[0040] Fifth step: Place the cleaned and filtered product into an oven and dry at 85°C for 1 hour.

[0041] The sixth step involves calcining the dried product in a muffle furnace. After calcination, the product is cooled to obtain biomimetic burdock-like Mo-modified Na2Mn8O. 16 Nanomaterials. The calcination temperature is 450℃, with the heating program set for 2 hours, cooling to below 200℃ for 2 hours, and the isothermal calcination time for 5 hours.

[0042] Example 2

[0043] The first step is to disperse 5.8068g of sodium molybdate dihydrate in 60mL of deionized water and stir for 0.5 hours.

[0044] The second step is to add 3.7927g of potassium permanganate and 4.3243g of urea to the solution and continue stirring for 1 hour.

[0045] The third step is to transfer the resulting mixed solution to a hydrothermal reactor, place it in an oven, and react it at a constant temperature of 160 °C for 6 hours, and then allow it to cool naturally to room temperature.

[0046] The fourth step is to remove the reaction product from the hydrothermal reactor and perform a cleaning operation. The reaction product is placed in pure water to form a suspension, and then ultrasonically cleaned for 3 minutes in an ultrasonic cleaner. The suspension is then filtered, and the process is repeated a total of 5 times.

[0047] Fifth step: Place the cleaned and filtered product into an oven and dry at 85°C for 1 hour.

[0048] The sixth step involves calcining the dried product in a muffle furnace. After calcination, the product is cooled to obtain biomimetic burdock-like Mo-modified Na2Mn8O. 16 Nanomaterials. The calcination temperature is 450℃, with the heating program set for 2 hours, cooling to below 200℃ for 2 hours, and the isothermal calcination time for 5 hours.

[0049] Figure 1 This demonstrates biomimetic burdock-like Mo-modified Na2Mn8O 16 XRD pattern of the nanomaterial. All diffraction peaks of the prepared material are associated with the tetragonal phase Na₂Mn₈O₃. 16 The product showed a perfect match to the standard diffraction card (PDF#29-1244), with no impurity diffraction peaks, confirming high purity. The characteristic diffraction peaks at 12.52°, 18.46°, 28.31°, and 37.18° corresponded to Na₂Mn₈O₃, respectively. 16 The crystal planes (110), (200), (310), and (211) of the crystal; the sharp peaks and intensity distributions of each diffraction peak are in high agreement with the standard spectrum, indicating excellent crystallinity of the sample. Mo-modified Na₂Mn₈O 16 The structural features of nanomaterials not only provide a rapid transport channel for zinc ion migration, but also effectively buffer the lattice strain generated during charge-discharge cycles, laying a structural foundation for improving the electrochemical performance of materials.

[0050] Figure 2 Na2Mn8O modified with biomimetic burdock-like Mo 16 SEM images of the nanomaterials clearly show nanospherical particles. These nanospheres exhibit a relatively uniform size distribution, with diameters ranging from approximately 100-200 nanometers, demonstrating a high specific surface area. The surface of these nanoparticles is actually composed of numerous tiny, bristle-like protrusions. These bristle structures are extremely fine in diameter, approximately 30-50 nanometers in length, and are radially distributed, resembling cocklebur seeds, forming a three-dimensional network structure with open pores. This unique surface morphology not only significantly increases the specific surface area of ​​the material but also provides an ideal interfacial environment for ion transport and electrolyte wetting.

[0051] Figure 3 Na2Mn8O modified with biomimetic burdock-like Mo 16 XPS full spectrum of nanomaterials. Figure 3 As can be seen in (a), the material surface is mainly composed of four elements: Mn, O, Na, and Mo. Figure 3In the Mo 3d fine spectrum of (b), a pair of characteristic double peaks with binding energies at 231.49 eV and 234.65 eV were observed, corresponding to Mo 3d... 5 / 2 and Mo 3d 3 / 2 The energy level, this binding energy position is related to Mo 6+ The typical characteristics are completely consistent. Figure 3 The Na 1s energy level spectrum in (c) shows that its main peak is located at 1070.71 eV, and this binding energy position clearly corresponds to the ionic bonding between Na and O. Figure 3 (d) The Mn 2p fine spectrum exhibits typical characteristics of manganese oxides, where Mn 2p 3 / 2 and Mn 2p 1 / 2 The binding energies are 641.47 eV and 653.37 eV, respectively, and the spin-orbit splitting energy is 11.9 eV. Through the analysis of Mn 2p... 3 / 2 Peak fitting revealed two characteristic sub-peaks at 641.73 eV and 644.04 eV, corresponding to Mn, respectively. 3+ and Mn 4+ The chemical state. In Figure 3 In the O 1s fine spectrum of (e), the main peak at 529.15 eV belongs to lattice oxygen, representing the Mn-O bond in the main structure of the material; the characteristic peak at 530.59 eV comes from the Na-O bond, further confirming the successful embedding and stable existence of Na ions in the tunnel structure; while the broader peak at 531.73 eV can be attributed to surface adsorbed oxygen species.

[0052] Figure 4 Na2Mn8O modified with biomimetic burdock-like Mo 16 The EDS diagrams of the nanomaterials showed characteristic peaks of Mn, O, Na, and Mo in the analytical region, confirming that Mo has been successfully introduced into the composite material system.

[0053] Figure 5 Na2Mn8O modified with biomimetic burdock-like Mo 16 Elemental distribution diagram of nanomaterials. In the nanosphere region, Mo exhibits a highly uniform distribution, completely overlapping with the distribution regions of Mn and O, indicating that Mo has been successfully doped into Na₂Mn₈O. 16 In the crystal lattice, the high reactivity and large specific surface area during nanoparticle formation are beneficial for the uniform doping of Mo species.

[0054] Figure 6 Na2Mn8O modified with biomimetic burdock-like Mo 16 Infrared spectrum of nanomaterials. Located at 536.21 cm⁻¹. -1The strong absorption peak at that point can be clearly attributed to Mn in the [MnO6] octahedral structure. 3+ The symmetric stretching vibration mode of the –O bond is a typical indicator of the presence of octahedral coordination units in manganese oxides. At 582.5 cm⁻¹ -1 The absorption peak at 740.66 cm⁻¹ originates from the asymmetric stretching vibration of the Mn–O bond in the [MnO₆] octahedron. -1 With 840.96 cm -1 The two observed intermediate-intensity absorption peaks can be clearly identified as Mn. 4+ The stretching vibration modes of the -O bond confirm the presence of high-valence Mn in the material. 4+ Ions, forming Mn 3+ / Mn 4+ A mixed valence system. 646.15 cm -1 The weak absorption peak appearing at this point corresponds to Mn 3+ The bending vibration mode of –O reflects the minute torsion of the octahedral structure. Furthermore, 464.84 cm -1 The vibration signal at the point can be attributed to the stretching vibration of the Na–O bond, indicating that the Na ion has been successfully embedded in the tunnel structure composed of manganese oxygen octahedra and has formed a stable ionic bond with the framework oxygen.

[0055] Figure 7 Na2Mn8O modified with biomimetic burdock-like Mo 16 Raman spectra of nanomaterials at 637.56 cm⁻¹ -1 The strong Raman peak appearing at [0.05] corresponds to the symmetric stretching vibration mode of the Mn–O bond in the [MnO6] octahedron. Meanwhile, at 294.27 cm⁻¹... -1 The Raman peaks observed at this location are mainly attributed to lattice vibration modes related to Na–O bond motion. This low-frequency vibration signal reflects the local vibrational environment of Na ions in the material's tunnel structure, and its position and intensity are related to Na… + Occupancy rate and migration capacity in tunnels are closely related.

[0056] Example 3

[0057] The first step is to disperse 7.2585g of sodium molybdate dihydrate in 60mL of deionized water and stir for 0.5 hours.

[0058] The second step is to add 3.7927g of potassium permanganate and 4.3243g of urea to the solution and continue stirring for 1 hour.

[0059] The third step is to transfer the resulting mixed solution to a hydrothermal reactor, place it in an oven, and react it at a constant temperature of 160 °C for 6 hours, and then allow it to cool naturally to room temperature.

[0060] The fourth step is to remove the reaction product from the hydrothermal reactor and perform a cleaning operation. The reaction product is placed in pure water to form a suspension, and then ultrasonically cleaned for 3 minutes in an ultrasonic cleaner. The suspension is then filtered, and the process is repeated a total of 5 times.

[0061] Fifth step: Place the cleaned and filtered product into an oven and dry at 85°C for 1 hour.

[0062] The sixth step involves calcining the dried product in a muffle furnace. After calcination, the product is cooled to obtain biomimetic burdock-like Mo-modified Na2Mn8O. 16 Nanomaterials. The calcination temperature is 450℃, with the heating program set for 2 hours, cooling to below 200℃ for 2 hours, and the isothermal calcination time for 5 hours.

[0063] Example 4

[0064] The first step is to disperse 8.7102g of sodium molybdate dihydrate in 60mL of deionized water and stir for 0.5 hours.

[0065] The second step is to add 3.7927g of potassium permanganate and 4.3243g of urea to the solution and continue stirring for 1 hour.

[0066] The third step is to transfer the resulting mixed solution to a hydrothermal reactor, place it in an oven, and react it at a constant temperature of 160 °C for 6 hours, and then allow it to cool naturally to room temperature.

[0067] The fourth step is to remove the reaction product from the hydrothermal reactor and perform a cleaning operation. The reaction product is placed in pure water to form a suspension, and then ultrasonically cleaned for 3 minutes in an ultrasonic cleaner. The suspension is then filtered, and the process is repeated a total of 5 times.

[0068] Fifth step: Place the cleaned and filtered product into an oven and dry at 85°C for 1 hour.

[0069] The sixth step involves calcining the dried product in a muffle furnace. After calcination, the product is cooled to obtain biomimetic burdock-like Mo-modified Na2Mn8O. 16 Nanomaterials. The calcination temperature is 450℃, with the heating program set for 2 hours, cooling to below 200℃ for 2 hours, and the isothermal calcination time for 5 hours.

[0070] Example 5

[0071] Na2Mn8O prepared in Examples 1-4 with biomimetic burdock-like Mo-modified form 16 Nanomaterials are used to prepare the positive electrode for aqueous zinc-ion batteries.

[0072] The first step is to weigh 0.16 g of biomimetic cocklebur-like Mo-modified Na2Mn8O. 16The nanomaterials and 0.02 g of acetylene black were thoroughly ground and mixed in an agate mortar.

[0073] The second step involves dissolving 0.02 g of polyvinylidene fluoride in 0.6 mL of N-methylpyrrolidone to prepare an adhesive. After stirring evenly, the adhesive is added to the mixed powder obtained in the first step and further mixed into a uniform slurry.

[0074] The third step is to coat the obtained slurry onto the surface of a stainless steel foil with a thickness of 0.01 mm and dry it in an oven at 80 ℃ for 1 h.

[0075] The fourth step is to cut the stainless steel foil into 10 mm diameter discs after the active material has dried completely, which will be used as the positive electrode of the battery.

[0076] The fifth step involves assembling an aqueous zinc-ion battery using a zinc sheet as the negative electrode, glass fiber paper as the separator, and a mixed solution of 2 mol / L ZnSO4 and 0.2 mol / L MnSO4 as the electrolyte. After assembly, the battery is left to stand for 24 hours for subsequent electrochemical testing.

[0077] Figure 8 Na2Mn8O modified with biomimetic burdock-like Mo 16 The nanomaterials are used as the cathode material in an aqueous zinc-ion battery, and the charge / discharge cycles are shown. The charge / discharge test currents were set at 50 mA / g, 100 mA / g, 200 mA / g, 300 mA / g, and 500 mA / g. The nanomaterials prepared in Example 2 exhibited the highest discharge capacity of 365.96 mAh·g at a current density of 50 mA / g. -1 .

[0078] Figure 9 Na2Mn8O modified with biomimetic burdock-like Mo 16 Cyclic voltammogram of an aqueous zinc-ion battery with nanomaterials as the cathode. The oxidation and reduction peaks are sharp, and the potential difference between them is small, indicating that the electrode reaction has high reversibility and fast kinetic characteristics, and low polarization. This is attributed to the modification effect of Mo on the material.

[0079] Figure 10 Na2Mn8O modified with biomimetic burdock-like Mo 16 The AC impedance curves of an aqueous zinc-ion battery with nanomaterials as the positive electrode are shown. As the amount of sodium molybdate dihydrate added increases to 48 mmol, the total electrode impedance significantly increases, with both charge transfer impedance and interfacial film impedance showing increases. An addition of 24 mmol of sodium molybdate dihydrate exhibits the best effect in improving material capacity, stability, and reaction kinetics.

[0080] Based on the disclosure in the foregoing specification, those skilled in the art can make appropriate changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments described above, and some modifications and changes to the present invention should also fall within the protection scope of the claims of the present invention.

Claims

1. A biomimetic burdock-like Mo-modified Na2Mn8O 16 Nanomaterials, characterized by: Its XRD pattern shows characteristic diffraction peaks at 2θ angles of 12.52°, 18.46°, 28.31°, and 37.18°; in its XPS spectrum, the binding energies of Mo 3d orbitals are at 231.49 eV and 234.65 eV, the binding energies of O 1s orbitals are at 529.15 eV and 530.59 eV, the binding energies of Mn 2p orbitals are at 641.47 eV and 653.37 eV, and the binding energy of Na 1s orbitals is at 1070.71 eV; Mo has a +6 valence, while Mn has both +3 and +4 valences.

2. The biomimetic burdock-like Mo-modified Na2Mn8O as described in claim 1 16 The method for preparing nanomaterials is characterized by, Includes the following steps: The first step is to disperse sodium molybdate dihydrate in deionized water, then add potassium permanganate and urea in sequence, and stir until the mixture is homogeneous. The second step is to transfer the resulting mixed solution to a hydrothermal reactor, place it in an oven for constant temperature reaction, and allow it to cool naturally to room temperature after the reaction is complete. The third step is to remove the reaction product, wash and filter it, and then dry it in an oven. In the fourth step, the dried product was calcined in a muffle furnace under air atmosphere. After cooling, the biomimetic Xanthium-like Mo-modified Na2Mn8O 16 nanomaterials.

3. The preparation method according to claim 2, characterized in that: In the first step, the molar ratio of sodium molybdate dihydrate to potassium permanganate is 1:

1.

4. The preparation method according to claim 2, characterized in that: In the first step, the molar ratio of urea to sodium molybdate dihydrate is 3:

1.

5. The preparation method according to claim 2, characterized in that: In the second step, the isothermal reaction is carried out at a temperature of 160°C for 6 hours.

6. The preparation method according to claim 2, characterized in that: In the third step, the reaction product is washed with pure water. Specifically, the product is placed in pure water to form a suspension, sonicated for 3 minutes, and then filtered. This washing process is repeated a total of 5 times.

7. The preparation method according to claim 2, characterized in that: In the third step, the drying temperature is 85°C and the drying time is 1 hour.

8. The preparation method according to claim 2, characterized in that: In the fourth step, the calcination temperature is 450℃ and the constant temperature calcination time is 5 hours; of which, the time to heat up to 450℃ is 2 hours, and the time to cool down to below 200℃ after calcination is 2 hours.

9. The biomimetic caper-like Mo-modified Na2Mn8O 16 Application of nanomaterials in positive electrode of aqueous zinc-ion battery.

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