Preparation method of pistil-shaped lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material
By preparing lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite materials in the shape of flower stamens, the problems of poor conductivity and structural instability of manganese-based oxides in aqueous zinc-ion batteries were solved, realizing the low-cost preparation and application of high-performance cathode materials.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ANYANG INST OF TECH
- Filing Date
- 2026-02-14
- Publication Date
- 2026-05-15
AI Technical Summary
Existing manganese-based oxide cathode materials suffer from poor conductivity, manganese ion dissolution, and structural degradation in aqueous zinc-ion batteries. The synergistic regulation mechanism of multiphase composite materials has not been fully studied.
A method for preparing lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite materials with a stamen-like structure was adopted. Through hydrothermal reaction, filtration, drying and high-temperature calcination, combined with lanthanum doping, a fluffy cluster structure of densely aggregated nanoneedle-like units was formed, constructing a three-dimensional conductive network with high specific surface area and well-developed ion channels.
It significantly improves the electrochemical performance of the material, enhances the stability and capacity of the cathode in aqueous zinc-ion batteries, and enables low-cost, large-scale industrial production of green and environmentally friendly synthesis.
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Abstract
Description
Technical Field
[0001] This invention discloses a method for preparing a lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material in the shape of a flower stamen, which belongs to the field of aqueous zinc-ion battery technology. Background Technology
[0002] As the global energy structure shifts towards sustainability, developing efficient, safe, and low-cost electrochemical energy storage systems has become a key research task. Among numerous energy storage technologies, aqueous zinc-ion batteries have shown broad application prospects in large-scale energy storage due to their advantages such as high safety, environmental friendliness, abundant zinc resources, and high theoretical capacity. However, the commercialization of energy storage technologies is largely constrained by the development bottleneck of cathode materials. Ideal cathode materials must simultaneously satisfy high specific capacity, strong ion conductivity, and good structural stability. Among many candidate materials, manganese-based oxides have attracted much attention due to their abundant reserves and high theoretical capacity resulting from multi-valence state conversion mechanisms, but their practical application still faces challenges such as poor conductivity, manganese ion dissolution during cycling, and structural degradation caused by charge and discharge.
[0003] To overcome the aforementioned limitations, researchers have focused on improving the electrochemical performance of materials through modification. Current strategies mainly include heteroelement doping, nanostructure design, and composites. Notably, besides single manganese oxides, constructing multiphase composites has become another important direction. These materials, through the functional complementarity of different phases, are expected to synergistically enhance capacity, conductivity, and structural stability. Currently, most modification work focuses on single-phase systems or empirical composites. However, the synergistic regulation mechanism of each phase in a multiphase composite system to the overall performance is a problem worthy of attention. Summary of the Invention
[0004] To address the challenges of using composite manganese-based materials as cathode materials in aqueous zinc-ion batteries, this invention provides a method for preparing a stamen-shaped lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material. Using lanthanum chloride heptahydrate, manganese nitrate aqueous solution, and urea as raw materials, these are dissolved in pure water. The stamen-shaped lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material is obtained through hydrothermal reaction, filtration, drying, and high-temperature calcination. This synthesis method is simple, low-cost, and suitable for large-scale industrial production.
[0005] The lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material with a stamen-like shape as described in this invention is characterized by the following: XRD diffraction peaks at 24.65°, 31.73°, 33.02°, and 56.67°; XPS peaks at 285.69 eV, 287.34 eV, 529.03 eV, 641.58 eV, 834.65 eV, and 851.18 eV; lanthanum is in a +3 valence state, and manganese is in a coexisting +2, +3, and +4 valence states.
[0006] This invention also provides a method for preparing the lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material with a stamen-like shape, comprising the following steps:
[0007] The first step is to disperse lanthanum chloride heptahydrate in pure water, then add manganese nitrate aqueous solution and urea in sequence, and stir until well mixed.
[0008] The second step is to place the well-stirred solution into a hydrothermal reactor, react it at a constant temperature in an oven, and then allow it to cool down naturally.
[0009] The third step is to remove the product from the hydrothermal reactor, wash and filter it, and then put it into an oven to dry.
[0010] The fourth step involves calcination in a muffle furnace followed by cooling to obtain a lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material with a stamen-like structure.
[0011] Furthermore, in the above technical solution, in the first step, the molar ratio of manganese nitrate to urea is 97:300.
[0012] Furthermore, in the above technical solution, in the first step, the molar ratio of lanthanum chloride heptahydrate to manganese nitrate is 3:97.
[0013] Furthermore, in the above technical solution, in the second step, the constant temperature reaction temperature is 160℃, and the constant temperature reaction time is 6 hours.
[0014] Furthermore, in the above technical solution, in the third step, the reaction product is cleaned with pure water. The reaction product is placed in pure water to form a suspension, and then ultrasonicated in an ultrasonic cleaner for 5 minutes. The suspension is then filtered, and the process is repeated a total of 5 times.
[0015] Furthermore, in the above technical solution, in the third step, the drying temperature is 80℃ and the drying time is 1 hour.
[0016] Furthermore, in the above technical solution, in the fourth step, the calcination temperature is 450℃, and the constant temperature calcination time is 5 hours, of which the heating program is set for 2 hours and the cooling to below 200℃ for 2 hours.
[0017] This invention also provides the application of lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material in aqueous zinc-ion batteries.
[0018] Beneficial effects of the invention
[0019] 1. This invention prepares a lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material with a stamen-like structure through a simple and low-cost synthesis process. The entire preparation process has low pollution and meets green environmental protection requirements.
[0020] 2. By introducing lanthanum as a dopant, the electronic structure and reactivity of the material were effectively controlled. Combined with its unique flower-like micro-nano composite morphology, the performance of the MnCO3-Mn2O3-MnO2 ternary composite material was significantly improved.
[0021] 3. This material possesses a loose, clustered structure formed by the dense aggregation of nanoneedle-like units. The clusters are tightly attached to the surface of micron-sized crystals, with abundant nanoscale gaps between the units. This structure constructs a three-dimensional conductive network with a high specific surface area and well-developed ion channels, enabling it to exhibit stable electrochemical performance when used as the cathode in aqueous zinc-ion batteries. Attached Figure Description
[0022] Figure 1 The image shows the XRD pattern of the lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material in Example 3 of this invention.
[0023] Figure 2 This is a SEM image of the lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material in Example 3 of the present invention.
[0024] Figure 3 XPS spectra of the lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material in the flower-like shape of Example 3 of the present invention; wherein: (a) is the full XPS spectrum; (b) is the XPS spectrum of La3d; (c) is the XPS spectrum of Mn2p; (d) is the XPS spectrum of O1s; and (e) is the XPS spectrum of C1s.
[0025] Figure 4 This is the EDS image of the lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material in Example 3 of the present invention;
[0026] Figure 5 The image shows the elemental distribution of the lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material in the flower-like shape in Example 3 of this invention; where: (a) is the La elemental distribution; (b) is the Mn elemental distribution; (c) is the O elemental distribution; and (d) is the C elemental distribution.
[0027] Figure 6 The infrared spectrum of the lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material in the stamen-like shape in Example 3 of this invention;
[0028] Figure 7 The Raman spectrum of the lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material in the stamen-like shape in Example 3 of this invention;
[0029] Figure 8 This is a cyclic charge-discharge diagram of the lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material in Example 5 of the present invention.
[0030] Figure 9 The cyclic voltammogram of the lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material in Example 5 of this invention is shown.
[0031] Figure 10 The AC impedance diagram is shown for the lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material in Example 5 of this invention. Detailed Implementation
[0032] 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.
[0033] 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.
[0034] Example 1
[0035] First, weigh 0.0891g of lanthanum chloride heptahydrate, dissolve it in 60mL of purified water, and stir for 0.5 hours.
[0036] The second step involves adding 8.5037g of a 50% manganese nitrate aqueous solution and 4.3243g of urea to the well-mixed solution and stirring for 1 hour.
[0037] The third step is to put the above-mentioned well-stirred mixed solution into a hydrothermal reactor and react it at a constant temperature of 160°C in an oven for 6 hours, followed by natural cooling.
[0038] The fourth step is to remove the reaction product from the hydrothermal reactor and perform a cleaning operation. Use pure water to clean and filter the reaction product, place the reaction product in pure water to form a suspension, and sonicate it in an ultrasonic cleaner for 5 minutes. Then filter the suspension. A total of 5 cleaning operations are performed.
[0039] Fifth step: Place the cleaned and filtered product into an oven and dry at 80°C for 1 hour.
[0040] The sixth step involves calcining the dried product in a muffle furnace. After calcination, the furnace is cooled to obtain the lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material with a flower-like structure. The calcination temperature is 450℃, with a heating program set for 2 hours, a cooling to below 200℃ for 2 hours, and a constant-temperature calcination time of 5 hours.
[0041] Example 2
[0042] First, weigh 0.1783g of lanthanum chloride heptahydrate, dissolve it in 60mL of purified water, and stir for 0.5 hours.
[0043] The second step involves adding 8.4178g of a 50% manganese nitrate aqueous solution and 4.3243g of urea to the well-mixed solution and stirring for 1 hour.
[0044] The third step is to put the above-mentioned well-stirred mixed solution into a hydrothermal reactor and react it at a constant temperature of 160°C in an oven for 6 hours, followed by natural cooling.
[0045] The fourth step is to remove the reaction product from the hydrothermal reactor and perform a cleaning operation. Use pure water to clean and filter the reaction product, place the reaction product in pure water to form a suspension, and sonicate it in an ultrasonic cleaner for 5 minutes. Then filter the suspension. A total of 5 cleaning operations are performed.
[0046] Fifth step: Place the cleaned and filtered product into an oven and dry at 80°C for 1 hour.
[0047] The sixth step involves calcining the dried product in a muffle furnace. After calcination, the furnace is cooled to obtain the lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material with a flower-like structure. The calcination temperature is 450℃, with a heating program set for 2 hours, a cooling to below 200℃ for 2 hours, and a constant-temperature calcination time of 5 hours.
[0048] Example 3
[0049] First, weigh 0.2674g of lanthanum chloride heptahydrate, dissolve it in 60mL of purified water, and stir for 0.5 hours.
[0050] The second step involves adding 8.3319g of a 50% manganese nitrate aqueous solution and 4.3243g of urea to the well-mixed solution and stirring for 1 hour.
[0051] The third step is to put the above-mentioned well-stirred mixed solution into a hydrothermal reactor and react it at a constant temperature of 160°C in an oven for 6 hours, followed by natural cooling.
[0052] The fourth step is to remove the reaction product from the hydrothermal reactor and perform a cleaning operation. Use pure water to clean and filter the reaction product, place the reaction product in pure water to form a suspension, and sonicate it in an ultrasonic cleaner for 5 minutes. Then filter the suspension. A total of 5 cleaning operations are performed.
[0053] Fifth step: Place the cleaned and filtered product into an oven and dry at 80°C for 1 hour.
[0054] The sixth step involves calcining the dried product in a muffle furnace. After calcination, the furnace is cooled to obtain the lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material with a flower-like structure. The calcination temperature is 450℃, with a heating program set for 2 hours, a cooling to below 200℃ for 2 hours, and a constant-temperature calcination time of 5 hours.
[0055] Figure 1 The XRD pattern of the lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material is shown. All diffraction peaks are assigned to rhombohedral MnCO3 (PDF#04-011-3970), orthorhombic Mn2O3 (PDF#04-007-0856), and tetragonal MnO2 (PDF#01-071-4824), with no impurity phase peaks. The peaks at 24.65° and 31.73° correspond to the (012) and (104) crystal planes of the MnCO3 phase; the peak at 33.02° corresponds to the (222) crystal plane of the Mn2O3 phase; and the peak at 56.67° corresponds to the (211) crystal plane of the MnO2 phase.
[0056] Figure 2 The image shows a SEM image of a lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material resembling a flower stamen. Microscopically, it exhibits a loose, clustered structure composed of densely grown and aggregated nanoneedle-like units. These clusters are tightly attached to the surface of micron-sized crystals, with abundant nanoscale gaps between the units, demonstrating significant micro-nano composite characteristics. This structure constructs a three-dimensional conductive network with high specific surface area and well-developed ion channels, effectively improving the electrochemical performance of the composite material when used as the cathode in aqueous zinc-ion batteries.
[0057] Figure 3 XPS image of lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material with a stamen-like shape. Figure 3 The full spectrum of (a) confirms that the material surface is mainly composed of Mn, O, C and La elements, and no other impurity elements were detected. Figure 3 (b) shows the La 3d spectrum at 834.65 eV. 5 / 2 The main peak and the La 3d at 851.18 eV 3 / 2The main peak, with a spin-orbit splitting value of 16.53 eV, and its corresponding satellite peaks at 838.25 eV and 855.14 eV, are La 3+ The typical characteristics indicate that the doped La exists in the +3 valence state. Figure 3 (c) shows the Mn 2p spectrum, indicating that Mn 2p 3 / 2 and Mn 2p 1 / 2 The main peaks are located at 641.58 eV and 653.10 eV, respectively, for Mn 2p 3 / 2 Peak fitting revealed three components with binding energies at 641.21 eV, 642.64 eV, and 644.43 eV, which were assigned to Mn, respectively. 2+ Mn 3+ and Mn 4+ . Figure 3 In (d), the peaks at 529.03 eV and 530.92 eV in the O 1s spectrum can be identified as lattice oxygen and oxygen in carbonate, respectively. Figure 3 The C 1s spectrum in (e) shows that the characteristic peak at 288.82 eV is clearly attributed to carbonate, while the peaks at 284.11 eV, 285.69 eV and 287.34 eV correspond to surface-adsorbed carbon, CO and C=O species, respectively.
[0058] Figure 4 The image shows the EDS spectrum of the lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material in the shape of a flower stamen. The elements Mn, O, C and La can be observed from this spectrum.
[0059] Figure 5 The elemental distribution diagram of the lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material with a stamen-like shape is shown. The signal distribution profiles of Mn and O elements highly coincide with the cubic particle morphology, indicating that they are uniformly distributed in the main structure. The signal of C is slightly weaker, while the signal of La is stronger in the stamen-like morphology.
[0060] Figure 6 The infrared spectrum of the lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material with a stamen-like shape is shown at 424.33 cm⁻¹. -1 The absorption peak at 513.06 cm⁻¹ can be attributed to the stretching and bending vibration modes of the Mn–O lattice; while the peak at 513.06 cm⁻¹... -1 and 572.86 cm -1 The two absorption peaks correspond to Mn in the Mn2O3 phase, respectively. 3+ –O and MnO2 are in phase with Mn 4+ The characteristic stretching vibration of –O directly confirms the coexistence of multivalent manganese oxides in the material. Located at 669.30 cm⁻¹ -1 727.16 cm-1 and 852.54 cm -1 The absorption peaks are all attributed to the out-of-plane and in-plane bending vibration modes of carbonate ions, providing evidence for the existence of the MnCO3 phase. The peak is located at 1465.90 cm⁻¹. -1 and 1514.12 cm -1 The double peaks correspond to the asymmetric stretching vibration of the carbonate ion.
[0061] Figure 7 The Raman spectrum of the lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material with a stamen-like structure is shown. It is located at 74.09 cm⁻¹. -1 160.76cm -1 and 194.9 cm -1 The signal can be attributed to La. 3+ The low-frequency lattice vibrations induced by doping indicate that La ions have been successfully introduced into the lattice and have induced local structural distortions. Located at 296.3 cm⁻¹ -1 The strong peak belongs to Mn in the Mn2O3 phase. 3+ –O stretching vibration, and 651.19 cm -1 The sharp peak at that point corresponds to Mn in the MnO2 phase. 4+ The symmetrical stretching vibration of –O, and both are related to 527.41cm. -1 The Mn–O vibrational signals at the location jointly confirmed that Mn 3+ With Mn 4+ Coexistence of oxides. Meanwhile, located at 747.23 cm... -1 789.24cm -1 and 880.85 cm -1 The multiple peaks are attributed to the in-plane and out-of-plane bending vibrations of carbonate ions, while the peak at 1061.34 cm⁻¹ is... -1 The peak at that point corresponds to the symmetrical stretching vibration of the carbonate ion.
[0062] Example 4
[0063] First, weigh 0.4456g of lanthanum chloride heptahydrate, dissolve it in 60mL of purified water, and stir for 0.5 hours.
[0064] The second step involves adding 8.1601g of a 50% manganese nitrate aqueous solution and 4.3243g of urea to the well-mixed solution and stirring for 1 hour.
[0065] The third step is to put the above-mentioned well-stirred mixed solution into a hydrothermal reactor and react it at a constant temperature of 160°C in an oven for 6 hours, followed by natural cooling.
[0066] The fourth step is to remove the reaction product from the hydrothermal reactor and perform a cleaning operation. Use pure water to clean and filter the reaction product, place the reaction product in pure water to form a suspension, and sonicate it in an ultrasonic cleaner for 5 minutes. Then filter the suspension. A total of 5 cleaning operations are performed.
[0067] Fifth step: Place the cleaned and filtered product into an oven and dry at 80°C for 1 hour.
[0068] The sixth step involves calcining the dried product in a muffle furnace. After calcination, the furnace is cooled to obtain the lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material with a flower-like structure. The calcination temperature is 450℃, with a heating program set for 2 hours, a cooling to below 200℃ for 2 hours, and a constant-temperature calcination time of 5 hours.
[0069] Example 5
[0070] The lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite materials with flower-like shapes prepared in Examples 1-4 were used to prepare the positive electrode of an aqueous zinc-ion battery.
[0071] The first step is to weigh 0.24g of the lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material and 0.03g of acetylene black, and grind them thoroughly using an agate mortar.
[0072] The second step involves adding a binder made from a mixture of 0.03g polyvinylidene fluoride and 0.6mL of N-methylpyrrolidone to the ground product.
[0073] The third step is to coat the mixed slurry onto a stainless steel foil with a thickness of 0.01 mm and dry it at a constant temperature of 80°C for 1 hour.
[0074] The fourth step is to process the stainless steel foil into a positive electrode sheet with a diameter of 10mm after the active material is completely dried.
[0075] 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 mixture of 2 mol / L ZnSO4 solution and 0.2 mol / L MnSO4 solution as the electrolyte. The battery is then left to stand for 24 hours before testing.
[0076] Figure 8This is a charge-discharge diagram of an aqueous zinc-ion battery using a lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material as the positive electrode. 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 composite material prepared in Example 3 exhibited the highest initial discharge capacity. At a current density of 50 mA / g, its discharge capacity showed an activation-increasing trend with cycling, reaching a maximum of 392.0 mAh / g. After cycling at different rates, when the current density returned to 50 mA / g, the capacity further increased to 459.4 mAh / g.
[0077] Figure 9 This is a cyclic voltammogram of an aqueous zinc-ion battery using a lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material as the positive electrode. The figure shows that the lanthanum-doped sample exhibits distinct oxidation and reduction peaks, indicating high electrochemical activity of the material.
[0078] Figure 10 The figure shows the AC impedance curves of an aqueous zinc-ion battery using a lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material as the positive electrode. The graph indicates that the charge transfer resistance increases monotonically with increasing La doping concentration, which may be due to excess La. 3+ This is due to lattice distortion caused by doping. Therefore, 3% doping is the optimal doping level for lanthanum.
[0079] 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 disclosed and 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 lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material with a stamen-like shape, characterized in that: XRD diffraction peaks are at 24.65°, 31.73°, 33.02°, and 56.67°; XPS peaks are at 285.69 eV, 287.34 eV, 529.03 eV, 641.58 eV, 834.65 eV, and 851.18 eV. Lanthanum is in the +3 valence position, while manganese is in the +2, +3, and +4 valence positions.
2. The method for preparing the lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material in the stamen shape as described in claim 1, characterized in that, Includes the following steps: The first step is to disperse lanthanum chloride heptahydrate in pure water, then add manganese nitrate aqueous solution and urea in sequence, and stir until well mixed. The second step is to place the well-stirred solution into a hydrothermal reactor, react it at a constant temperature in an oven, and then allow it to cool down naturally. The third step is to remove the product from the hydrothermal reactor, wash and filter it, and then put it into an oven to dry. The fourth step involves calcination in a muffle furnace followed by cooling to obtain a lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material with a stamen-like structure.
3. The method for preparing the lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material with a stamen-like shape according to claim 2, characterized in that: In the first step, the molar ratio of manganese nitrate to urea is 97:
300.
4. The method for preparing the lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material according to claim 2, characterized in that: In the first step, the molar ratio of lanthanum chloride heptahydrate to manganese nitrate is 3:
97.
5. The method for preparing the lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material with a stamen-like shape according to claim 2, characterized in that: In the second step, the constant temperature reaction temperature is 160℃, and the reaction time is 6 hours.
6. The lanthanum-doped MnCO3-Mn2O3-MnO with a stamen-like structure according to claim 2 22 The method for preparing ternary composite materials is characterized by: In the third step, the reaction product is washed with pure water. The reaction product is placed in pure water to form a suspension, and then ultrasonicated in an ultrasonic cleaner for 5 minutes. The suspension is then filtered. The washing is repeated a total of 5 times.
7. The method for preparing the lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material in the shape of a flower stamen according to claim 2, characterized in that: In the third step, the drying temperature is 80℃ and the drying time is 1 hour.
8. The method for preparing the lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material in the shape of a flower stamen 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 heating program is set for 2 hours and the cooling to below 200℃ takes 2 hours.
9. The application of the lanthanum-doped MnCO3-Mn2O3-MnO2 ternary composite material as described in claim 1 in an aqueous zinc-ion battery.