Preparation method and application of a scale-like four-phase composite K-Mn-Mo oxide electrode material
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ANYANG INST OF TECH
- Filing Date
- 2026-06-11
- Publication Date
- 2026-08-07
AI Technical Summary
然而，锰氧化物本征导电性较差，电子传输能力有限，导致其在大电流密度下的倍率性能不佳；同时，在反复充放电过程中，离子的嵌入与脱出会引发显著的体积膨胀与收缩，易造成材料结构粉化和活性物质脱落，严重制约了其电化学性能的稳定性
[0019]该发明提供了鳞片状四相复合的K-Mn-Mo氧化物电极材料，该材料由MnMoO4、K2Mo4O13、MnO2和MoO3四相复合组成，质量占比分别分别为45.7%、20.2%、17.6%和16.5%。微观上呈现由纳米级薄片相互堆叠、定向排列而成的鳞片状结构。这种结构能够缓冲材料在充放电过程中的体积膨胀与收缩，减少结构粉化与脱落，从而在循环充放电过程中保持结构完整性，提升超级电容器的性能。制备过程也较为环保，不对环境产生污染。
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Abstract
Description
Technical Field
[0001] This invention discloses a flake-like four-phase composite K-Mn-Mo oxide electrode material, its preparation method and application, belonging to the field of supercapacitor technology in inorganic materials. Background Technology
[0002] Supercapacitors, as a novel energy storage device, have shown broad application prospects in fields such as electric vehicles and smart grids due to their high power density, rapid charge and discharge capabilities, long cycle life, and excellent safety. Based on their energy storage mechanisms, supercapacitors are mainly divided into two categories: electric double-layer capacitors and pseudocapacitors. Electric double-layer capacitors rely on electrostatic adsorption at the electrode-electrolyte interface to store charge, exhibiting excellent rate performance, but their specific capacitance is generally low due to limitations in the number of ions that can be adsorbed at the interface. Pseudocapacitors, on the other hand, utilize reversible redox reactions occurring on or near the surface of the electrode material to store energy, achieving a specific capacitance far exceeding that of electric double-layer capacitors. Therefore, the development of high-performance pseudocapacitive electrode materials has become a current research hotspot.
[0003] Among numerous pseudocapacitor materials, transition metal oxides have been extensively studied due to their diverse variable valence states, high theoretical specific capacitance, and good chemical stability. Manganese oxides, in particular, have attracted considerable attention due to their abundant resources, low cost, and environmental friendliness. However, manganese oxides exhibit poor intrinsic conductivity and limited electron transport capacity, resulting in poor rate performance at high current densities. Furthermore, during repeated charge-discharge cycles, ion insertion and extraction induce significant volume expansion and contraction, easily leading to material structure pulverization and active material shedding, severely restricting the stability of their electrochemical performance. These problems limit the practical application of manganese oxides in high-power, long-life supercapacitors. Summary of the Invention
[0004] To address the aforementioned technical problems, this invention provides a method for preparing a flake-like four-phase composite K-Mn-Mo oxide electrode material. Potassium permanganate, ammonium molybdate tetrahydrate, and ammonium fluoride are dissolved in pure water, and after a constant-temperature hydrothermal reaction, the product is filtered, then calcined in a muffle furnace. After cooling, the flake-like four-phase composite K-Mn-Mo oxide electrode material is obtained. This synthesis method is simple, easy to implement, and low in cost, making it suitable for large-scale industrial production.
[0005] The flake-like four-phase composite K-Mn-Mo oxide electrode material of this invention exhibits a flake-like structure at the microscopic level, consisting of nanoscale flakes stacked and oriented. In XRD, the 2θ values are 13.03°, 22.38°, 25.9°, and 27.45°; the XPS peak values are 641.87 eV, 653.42 eV, 232.29 eV, 235.42 eV, 530.32 eV, 292.65 eV, and 295.46 eV. The Mn element exhibits both +2 and +4 valence states, while the Mo element has a +6 valence state.
[0006] The preparation method of the flake-like four-phase composite K-Mn-Mo oxide electrode material of the present invention includes the following steps:
[0007] The first step is to disperse potassium permanganate in deionized water, then add ammonium molybdate tetrahydrate and ammonium fluoride in sequence, and stir until well mixed.
[0008] The second step is to place the mixed solution in 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 clean and filter the product in the hydrothermal reactor and then dry it in an oven.
[0010] The fourth step is to calcine the dried product in a muffle furnace and cool it down to obtain a flake-like four-phase composite K-Mn-Mo oxide electrode material.
[0011] Furthermore, in the above technical solution, in the first step, the molar ratio of potassium permanganate to ammonium molybdate tetrahydrate is 1:1.
[0012] Furthermore, in the above technical solution, in the first step, the molar ratio of ammonium molybdate tetrahydrate to ammonium fluoride is 1:3.
[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 10 hours.
[0014] Furthermore, in the above technical solution, in the third step, the reaction product is cleaned and filtered with pure water. The reaction product is placed in pure water to form a suspension, and then ultrasonicated in an ultrasonic cleaner for 4 minutes. The suspension is then filtered, and the product is cleaned a total of 4 times.
[0015] Furthermore, in the above technical solution, in the third step, the drying temperature is 85℃ and the drying time is 1 hour.
[0016] Furthermore, in the above technical solution, in the fourth step, the calcination temperature is 300℃, the constant temperature calcination time is 1 hour, wherein the heating program is set to 2 hours, and the cooling to below 200℃ takes 2 hours.
[0017] The present invention also provides the application of the aforementioned flake-like four-phase composite K-Mn-Mo oxide electrode material in supercapacitors.
[0018] Beneficial effects of the invention:
[0019] This invention provides a flake-like four-phase composite K-Mn-Mo oxide electrode material, which consists of MnMoO4 and K2Mo4O4. 13 The supercapacitor is composed of four phases: MnO2, MoO3, and MnO2, with mass percentages of 45.7%, 20.2%, 17.6%, and 16.5%, respectively. Microscopically, it exhibits a flake-like structure formed by stacked and oriented nanoscale flakes. This structure buffers the volume expansion and contraction of the material during charge and discharge, reducing structural pulverization and detachment, thus maintaining structural integrity during cyclic charge and discharge and improving the performance of the supercapacitor. The fabrication process is also relatively environmentally friendly and does not pollute the environment. Attached Figure Description
[0020] Figure 1 The image shows the XRD pattern of the flake-like four-phase composite K-Mn-Mo oxide electrode material in Example 1 of this invention.
[0021] Figure 2 XPS images of the flake-like four-phase composite K-Mn-Mo oxide electrode material in Example 1 of the present invention are shown below; (a) is the full XPS spectrum; (b) is the XPS spectrum of Mn2p; (c) is the XPS spectrum of Mo3d; (d) is the XPS spectrum of O1s; and (e) is the XPS spectrum of K2p.
[0022] Figure 3 This is a SEM image of the flake-like four-phase composite K-Mn-Mo oxide electrode material in Example 1 of the present invention;
[0023] Figure 4 This is the EDS image of the flake-like four-phase composite K-Mn-Mo oxide electrode material in Example 1 of the present invention;
[0024] Figure 5 The following is an elemental distribution diagram of the flake-like four-phase composite K-Mn-Mo oxide electrode material in Example 1 of the present invention; wherein: (a) is the distribution diagram of K element; (b) is the distribution diagram of Mn element; (c) is the distribution diagram of Mo element; and (d) is the distribution diagram of O element.
[0025] Figure 6 The infrared spectrum of the flake-like four-phase composite K-Mn-Mo oxide electrode material in Example 1 of this invention;
[0026] Figure 7This is the Raman spectrum of the flake-like four-phase composite K-Mn-Mo oxide electrode material in Example 1 of the present invention;
[0027] Figure 8 The flake-like four-phase composite K-Mn-Mo oxide electrode material in Example 5 of this invention is used at a current density of 0.001 A / cm². 2 GCD plot at time;
[0028] Figure 9 This is a specific capacity diagram of the flake-like four-phase composite K-Mn-Mo oxide electrode material in Example 5 of the present invention. Detailed Implementation
[0029] 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. In the following examples, unless otherwise specified, the reagents, materials, and instruments used are all conventional reagents, materials, and instruments, all of which are commercially available. The reagents involved can also be synthesized by conventional synthetic methods.
[0030] Example 1
[0031] First, weigh 0.6322g of potassium permanganate, disperse it in deionized water and stir. Then add 4.9435g of ammonium molybdate tetrahydrate and stir for 1 hour.
[0032] The second step is to add 0.4445g of ammonium fluoride to the well-mixed solution and stir for 1 hour.
[0033] The third step is to place the above mixed solution into a hydrothermal reactor and react it at a constant temperature of 160°C in an oven for 10 hours, followed by natural cooling.
[0034] The fourth step involves removing the reaction product from the hydrothermal reactor and cleaning it using purified water. The reaction product is then placed in purified water to form a suspension, which is ultrasonically cleaned for 4 minutes. The suspension is then filtered, and the process is repeated a total of four times.
[0035] Fifth step: Place the cleaned and filtered product into an oven and dry at 85°C for 1 hour.
[0036] The sixth step involves calcining the dried product in a muffle furnace. After calcination, the furnace is cooled to obtain a flake-like four-phase composite K-Mn-Mo oxide electrode material. The calcination temperature is 300℃, with a heating program set for 2 hours, a cooling to below 200℃ for 2 hours, and a constant-temperature calcination time of 1 hour.
[0037] from Figure 1As can be seen, the flake-like four-phase composite K-Mn-Mo oxide electrode material synthesized by hydrothermal method consists of MnMoO4 (PDF#04-012-5000), K2Mo4O 13 The material is composed of four phases: MnO2 (PDF#01-073-6026), MnO2 (PDF#04-022-7426), and MoO3 (PDF#01-078-4613). The sharp diffraction peaks confirm the material's high crystallinity. MnMoO4 and K2Mo4O 13 The mass percentages of MnO2 and MoO3 were 45.7%, 20.2%, 17.6%, and 16.5%, respectively. The peak at 13.03° corresponds to K2Mo4O. 13 The (101) crystal plane, the peak at 22.38° corresponds to the (110) crystal plane of MnO2, the peak at 25.9° corresponds to the (220) crystal plane of MnMoO4, and the peak at 27.45° corresponds to the (021) crystal plane of MoO3.
[0038] Figure 2 This is an XPS image of a flake-like four-phase composite K-Mn-Mo oxide electrode material. Figure 2 Characteristic peaks of Mn 2p, Mo 3d, O 1s and K 2p can be observed in the full spectrum of (a). Figure 2 In the high-resolution spectrum of Mn 2p in (b), 641.87 eV is attributed to Mn 2p. 3 / 2 Mn in the energy level 4+ Species, 653.42 eV corresponds to Mn 2p 1 / 2 Spin-orbit splitting peaks, which are related to Mn 2p 3 / 2 The spacing between the main peaks is approximately 11.55 eV, consistent with Mn. 4+ The typical characteristics of manganese are clearly demonstrated by the synergistic appearance of the aforementioned characteristic peaks, which confirms that manganese in the composite electrode material is primarily Mn. 2+ With Mn 4+ Mixed valence states coexist. Figure 2 (c) is the high-resolution spectrum of Mo 3d, showing the Mo 3d spectrum. 6+ The typical spin-orbit splitting double peak, in which Mo 3d 5 / 2 The peak is located at 232.29 eV, Mo 3d 3 / 2 The peak is located at 235.42 eV, and the distance between the two peaks is 3.13 eV, indicating that the Mo element in the material mainly exists in the +6 valence form, with a simple chemical environment, and is associated with MnMoO4 and K2Mo4O. 13 Mo in the MoO3 crystal phase 6+ The coordination environment is consistent. Figure 2(d) is the O 1s high-resolution spectrum. The main peak at 530.32 eV corresponds to lattice oxygen, which originates from Mn–O and Mo–O bonds and is an important component of the oxide crystal framework. Figure 2 (e) is the high-resolution spectrum of K 2p. 3 / 2 The peak is located at 292.65 eV, K 2p 1 / 2 The peak at 295.46 eV confirms the presence of the ionic state K. + The existence of.
[0039] Figure 3 This is a SEM image of a flake-like four-phase composite K-Mn-Mo oxide electrode material. Microscopically, it exhibits a flake-like structure composed of stacked and oriented nanoscale flakes. The nanosheets have smooth surfaces and clear edges, with abundant gaps and wrinkles between the layers and on the particle surface, providing ample channels for electrolyte penetration and ion diffusion. This structure can buffer the volume expansion and contraction of the material during charging and discharging, reducing structural pulverization and detachment, thereby improving the performance of the supercapacitor.
[0040] Figure 4 The image shows the EDS spectrum of the flake-like four-phase composite K-Mn-Mo oxide electrode material. Peaks for K, Mn, Mo, and O elements can be observed in the EDS spectrum.
[0041] Figure 5 The image shows the elemental distribution of the flake-like four-phase composite K-Mn-Mo oxide electrode material. K, Mn, Mo, and O elements are uniformly distributed in the lamellar structure without obvious segregation. The uniformity of elemental distribution is conducive to the formation of a stable framework structure.
[0042] Figure 6 The image shows the infrared spectrum of a flake-like four-phase composite K-Mn-Mo oxide electrode material. The wavelength is located at 559.35 cm⁻¹. -1 The absorption peak at 721.38 cm⁻¹ is attributed to the stretching vibration of the Mn-O bond, confirming the presence of the MnO₆ octahedral structure in the material. -1 858.32 cm -1 956.70 cm -1 and 997.20 cm -1 The absorption peak at this point corresponds to the stretching vibration of the Mo-O-Mo bridging oxygen bond and the Mo=O terminal double bond, indicating the existence of the MoO6 / MoO4 coordination structure. This is consistent with the presence of MnMoO4 and K2Mo4O. 13 The skeletal structure of the isomolybdate phase is consistent. 1398.39 cm -1 and 1614.42 cm -1 The absorption peaks at 3423.64 cm⁻¹ are attributed to the bending vibrations of the OH bond and the HOH bending vibrations of the adsorbed water molecules, respectively.-1 The broad peak at that point corresponds to the stretching vibration of the OH bond.
[0043] Figure 7 Raman spectra of a flake-like four-phase composite K-Mn-Mo oxide electrode material are shown. The image is located at 125.35 cm⁻¹. -1 and 152.93 cm -1 The Raman peak at this location is attributed to the low-frequency framework vibrations of MnO6 octahedrons and MoO6 octahedrons, confirming the presence of the manganese oxide and molybdate framework. (196.42 cm⁻¹) -1 221.65 cm -1 and 240.13 cm -1 The characteristic peak at 240.13 cm⁻¹ corresponds to the bending vibration of the Mn-O-Mo bridging oxygen bond, indicating the formation of a bimetallic oxide heterostructure; among which... -1 The nearby peak position matches the Raman shift characteristics of MnO2. 287.11 cm⁻¹ -1 The peak at 336.8 cm⁻¹ corresponds to the bending vibration mode of the Mo-O-Mo bridged oxygen bond. -1 and 375.07 cm -1 The characteristic peak at 818.18 cm⁻¹ corresponds to the stretching vibration of the Mn-O-Mo bridging oxygen bond. -1 The peak at 848.88 cm⁻¹ belongs to the symmetric stretching vibration of the Mo-O-Mo bridged oxygen bond; -1 The peak at 929.39 cm⁻¹ corresponds to the Mo-O-Mo asymmetric stretching vibration. -1 961.39 cm -1 and 992.76 cm -1 The peak at that point is attributed to the stretching vibration of the Mo=O end double bond.
[0044] Example 2
[0045] First, weigh 0.6717g of potassium permanganate, disperse it in deionized water and stir. Then add 5.2525g of ammonium molybdate tetrahydrate and stir for 1 hour.
[0046] The second step is to add 0.4445g of ammonium fluoride to the well-mixed solution and stir for 1 hour.
[0047] The third step is to place the above mixed solution into a hydrothermal reactor and react it at a constant temperature of 160°C in an oven for 10 hours, followed by natural cooling.
[0048] The fourth step involves removing the reaction product from the hydrothermal reactor and cleaning it using purified water. The reaction product is then placed in purified water to form a suspension, which is ultrasonically cleaned for 4 minutes. The suspension is then filtered, and the process is repeated a total of four times.
[0049] Fifth step: Place the cleaned and filtered product into an oven and dry at 85°C for 1 hour.
[0050] The sixth step involves calcining the dried product in a muffle furnace. After calcination, the furnace is cooled to obtain a flake-like four-phase composite K-Mn-Mo oxide electrode material. The calcination temperature is 300℃, with a heating program set for 2 hours, a cooling to below 200℃ for 2 hours, and a constant-temperature calcination time of 1 hour.
[0051] Example 3
[0052] First, weigh 0.5927g of potassium permanganate, disperse it in deionized water and stir. Then add 4.6345g of ammonium molybdate tetrahydrate and stir for 1 hour.
[0053] The second step is to add 0.4445g of ammonium fluoride to the well-mixed solution and stir for 1 hour.
[0054] The third step is to place the above mixed solution into a hydrothermal reactor and react it at a constant temperature of 160°C in an oven for 10 hours, followed by natural cooling.
[0055] The fourth step involves removing the reaction product from the hydrothermal reactor and cleaning it using purified water. The reaction product is then placed in purified water to form a suspension, which is ultrasonically cleaned for 4 minutes. The suspension is then filtered, and the process is repeated a total of four times.
[0056] Fifth step: Place the cleaned and filtered product into an oven and dry at 85°C for 1 hour.
[0057] The sixth step involves calcining the dried product in a muffle furnace. After calcination, the furnace is cooled to obtain a flake-like four-phase composite K-Mn-Mo oxide electrode material. The calcination temperature is 300℃, with a heating program set for 2 hours, a cooling to below 200℃ for 2 hours, and a constant-temperature calcination time of 1 hour.
[0058] Example 4
[0059] First, weigh 0.5531g of potassium permanganate, disperse it in deionized water and stir. Then add 4.3256g of ammonium molybdate tetrahydrate and stir for 1 hour.
[0060] The second step is to add 0.4445g of ammonium fluoride to the well-mixed solution and stir for 1 hour.
[0061] The third step is to place the above mixed solution into a hydrothermal reactor and react it at a constant temperature of 160°C in an oven for 10 hours, followed by natural cooling.
[0062] The fourth step involves removing the reaction product from the hydrothermal reactor and cleaning it using purified water. The reaction product is then placed in purified water to form a suspension, which is ultrasonically cleaned for 4 minutes. The suspension is then filtered, and the process is repeated a total of four times.
[0063] Fifth step: Place the cleaned and filtered product into an oven and dry at 85°C for 1 hour.
[0064] The sixth step involves calcining the dried product in a muffle furnace. After calcination, the furnace is cooled to obtain a flake-like four-phase composite K-Mn-Mo oxide electrode material. The calcination temperature is 300℃, with a heating program set for 2 hours, a cooling to below 200℃ for 2 hours, and a constant-temperature calcination time of 1 hour.
[0065] Example 5
[0066] The flake-like four-phase composite K-Mn-Mo oxide electrode material was prepared as the working electrode of a supercapacitor grown in situ on nickel foam.
[0067] First, weigh 0.6322g of potassium permanganate, disperse it in deionized water and stir. Then add 4.9435g of ammonium molybdate tetrahydrate and stir for 1 hour.
[0068] The second step is to add 0.4445g of ammonium fluoride to the well-mixed solution and stir for 1 hour.
[0069] The third step involves stirring the above mixed solution evenly, then adding nickel foam with dimensions of 1 cm × 1 cm × 1.5 mm. The mixed solution and nickel foam are then placed together in a hydrothermal reactor and reacted at a constant temperature of 160°C in an oven for 10 hours, followed by natural cooling.
[0070] The fourth step involves removing the nickel foam from the hydrothermal reactor and cleaning it using purified water and filtering. The reaction product is then placed in purified water to form a suspension, which is ultrasonically cleaned for 4 minutes each time, for a total of 4 cleaning cycles.
[0071] The fifth step is to place the cleaned nickel foam into an oven and dry it at 85°C for 1 hour.
[0072] The sixth step involves calcining the dried nickel foam in a muffle furnace. After calcination, the furnace is cooled to obtain nickel foam with a four-phase composite K-Mn-Mo oxide electrode material. The calcination temperature is 300℃, with a heating program set for 2 hours, a cooling program to below 200℃ for 2 hours, and a constant-temperature calcination time of 1 hour.
[0073] The seventh step involves assembling a three-electrode system, with a platinum electrode selected as the counter electrode, a mercuric oxide electrode as the reference electrode, and a 3 mol / L KOH solution as the electrolyte.
[0074] Figure 8 The image shows the GCD of the flake-like four-phase composite K-Mn-Mo oxide electrode material. The image reveals that this electrode material exhibits excellent charge storage and release capabilities, demonstrating superior electrochemical performance. Calculations show that at 0.002 A / cm²... 2 At the specified current density, the capacitance of the flake-like four-phase composite K-Mn-Mo oxide electrode material can reach up to 11.772 F / cm. 2 .
[0075] Figure 9 The specific capacitance diagram shows the four-phase composite K-Mn-Mo oxide electrode material grown in situ on nickel foam, at 0.003 A / cm². 2 、 0.005A / cm 2 At current density, the specific capacitance is 9.168 F / cm. 2 and 7.665 F / cm 2 This indicates that the material exhibits stable electrochemical performance when applied in supercapacitors.
[0076] Based on the description 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 four-phase composite K-Mn-Mo oxide electrode material, characterized in that: The material contains MnMoO4 and K2Mo4O 13 The mass percentages of MnO2 and MoO3 are 45.7%, 20.2%, 17.6%, and 16.5%, respectively. Microscopically, it exhibits a scale-like structure composed of stacked and oriented nanoscale flakes. In the XRD pattern, the 2θ characteristic diffraction peaks are located at 13.03°, 22.38°, 25.9°, and 27.45°. In the XPS pattern, the characteristic peaks are located at 641.87 eV, 653.42 eV, 232.29 eV, 235.42 eV, 530.32 eV, 292.65 eV, and 295.46 eV. Among them, Mn exists in both +2 and +4 valence forms, while Mo exists in +6 valence form.
2. The method for preparing the flake-like four-phase composite K-Mn-Mo oxide electrode material as described in claim 1, characterized in that, Includes the following steps: The first step is to disperse potassium permanganate in deionized water, then add ammonium molybdate tetrahydrate and ammonium fluoride in sequence, and stir until well mixed. The second step is to place the mixed solution in 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 clean and filter the product in the hydrothermal reactor and then dry it in an oven. The fourth step is to calcine the dried product in a muffle furnace and cool it down to obtain a flake-like four-phase composite K-Mn-Mo oxide electrode material.
3. The method for preparing the material according to claim 2, characterized in that: In the first step, the molar ratio of potassium permanganate to ammonium molybdate tetrahydrate is 1:
1.
4. The method for preparing the material according to claim 2, characterized in that: In the first step, the molar ratio of ammonium molybdate tetrahydrate to ammonium fluoride is 1:
3.
5. The method for preparing the material according to claim 2, characterized in that: In the second step, the constant temperature reaction temperature is 160℃, and the constant temperature reaction time is 10 hours.
6. The method for preparing the material according to claim 2, characterized in that: In the third step, the reaction product is washed and filtered with pure water. The reaction product is placed in pure water to form a suspension, and then ultrasonicated in an ultrasonic cleaner for 4 minutes. The suspension is then filtered, and the product is washed a total of 4 times.
7. The method for preparing the material according to claim 1, characterized in that: In the third step, the drying temperature is 85℃ and the drying time is 1 hour.
8. The method for preparing the material according to claim 1, characterized in that: In the fourth step, the calcination temperature is 300℃, and the constant temperature calcination time is 1 hour, of which the heating program is set to 2 hours and the cooling to below 200℃ takes 2 hours.
9. The application of the flake-like four-phase composite K-Mn-Mo oxide electrode material as described in claim 1 in supercapacitors.