Cerium ion doped manganese dioxide composite material, preparation method thereof and application of cerium ion doped manganese dioxide composite material in aqueous magnesium ion capacitor
By combining cerium ion-doped manganese dioxide composite materials with activated carbon, the problem of low insertion/extraction efficiency of magnesium ion battery cathode materials was solved, realizing the performance improvement of high-efficiency aqueous magnesium ion capacitors and environmentally friendly, low-cost energy storage devices.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-29
- Publication Date
- 2026-03-13
AI Technical Summary
Existing magnesium-ion battery cathode materials have difficulty achieving efficient magnesium ion insertion/extraction over a wide composition range, resulting in sluggish ion diffusion kinetics and low reversible specific capacity, which affects electrochemical performance and cycle stability.
A cerium ion-doped manganese dioxide composite material was used as the positive electrode material. The cerium ion-doped manganese dioxide composite material (Ce-MnO2) was prepared by hydrothermal reaction and combined with activated carbon to form an asymmetric aqueous magnesium ion capacitor. This optimized the diffusion channel of Mg2+ and improved the electrochemical performance of the material.
The specific capacitance of the aqueous magnesium ion capacitor was significantly improved, the discharge time was increased by about 4234 seconds, and the specific capacitance reached 254.64 F/g, an increase of about 1.9 times. The material stability and electron transfer performance were improved, and the synthesis process was simple, environmentally friendly and low cost.
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Figure CN121662616A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of electrode material technology, specifically relating to a cerium ion-doped manganese dioxide composite material, its preparation method, and its application in aqueous magnesium ion capacitors. Background Technology
[0002] Lithium-ion batteries currently dominate the electrochemical energy storage market due to their high energy density, rapid charge / discharge capabilities, and long cycle life. However, global lithium resources are limited and highly concentrated in a few countries, posing supply chain risks and raising concerns about their sustainability. To address the growing energy storage demands of the future, there is an urgent need to develop alternative battery technologies based on elements more abundant on Earth. Using divalent magnesium ions (Mg...) as an example... 2+ ) replaces monovalent lithium ions (Li + Magnesium-ion batteries are considered a highly promising candidate technology. Besides being approximately 1000 times more abundant than lithium in the Earth's crust, magnesium also has a lower reduction potential, and each magnesium ion can transfer twice the charge of lithium. Compared to lithium-ion batteries, magnesium-ion batteries also possess a higher theoretical volumetric capacity (approximately 3833 mAh / cm³). 3 Magnesium-ion batteries offer advantages such as high safety and low cost. However, a key challenge for magnesium-ion batteries is the lack of cathode materials capable of achieving efficient magnesium ion insertion / extraction across a wide composition range. For cathode materials, divalent magnesium... 2+ Strong electrostatic interactions exist between ions and the crystal lattice, which can lead to sluggish ion diffusion kinetics and low reversible specific capacity. Therefore, a material with a reasonable intercalation structure is designed, which involves increasing the interlayer spacing and optimizing Mg... 2+ The diffusion channels help reduce the ion migration energy barrier, promote the efficient insertion and extraction of magnesium ions, and thus significantly improve the electrochemical performance and cycle stability of the material. Summary of the Invention
[0003] To address the aforementioned technical problems, the present invention aims to provide a cerium ion-doped manganese dioxide composite material, its preparation method, and its application in an aqueous magnesium ion capacitor. By using the cerium ion-doped manganese dioxide composite material as the positive electrode material in an aqueous magnesium ion capacitor, the specific capacitance of the aqueous magnesium ion capacitor is significantly improved.
[0004] To achieve the above-mentioned objectives, the technical solution adopted by the present invention is: a cerium ion-doped manganese dioxide composite material, the preparation method of which includes: adding potassium permanganate, manganese sulfate monohydrate and cerium acetate to deionized water, stirring to dissolve and disperse evenly, transferring the resulting mixed solution to a high-pressure reactor lined with polytetrafluoroethylene for hydrothermal reaction, centrifuging and washing, drying, and obtaining cerium ion-doped manganese dioxide composite material (Ce-MnO2).
[0005] Furthermore, by mass ratio, potassium permanganate: manganese sulfate monohydrate: cerium acetate = (15 - 17): (2 - 4): 1.
[0006] Furthermore, the hydrothermal reaction is carried out at a temperature of 120 ℃ - 190 ℃ and for a time of 15 h - 17 h.
[0007] The present invention relates to the application of cerium ion-doped manganese dioxide composite material as a positive electrode material in aqueous magnesium ion capacitors.
[0008] Furthermore, the method includes the following steps:
[0009] 1) Preparation of positive electrode: After the cerium ion doped manganese dioxide composite material (Ce-MnO2) is mixed evenly with binder and conductive material, a small amount of NMP is added dropwise as a dispersion liquid. After mixing evenly, the resulting slurry is directly coated on the substrate and dried to obtain a positive electrode sheet coated with Ce-MnO2.
[0010] 2) Preparation of negative electrode: After the activated carbon, binder and conductive material are mixed evenly, a small amount of NMP is added dropwise as a dispersion liquid. After mixing evenly, the resulting slurry is directly coated on the substrate and dried to obtain a negative electrode sheet coated with activated carbon.
[0011] 3) Preparation of aqueous magnesium ion capacitor: The negative electrode plate coated with activated carbon is placed in the center of the negative electrode shell, then the separator is placed in the negative electrode shell, and electrolyte is added to fully wet the separator. Then the positive electrode plate coated with Ce-MnO2 is placed in contact with the wetted separator. Finally, the gasket and spring are placed in and sealed to obtain the aqueous magnesium ion capacitor.
[0012] Furthermore, the adhesive is carboxymethyl cellulose or polyvinylidene fluoride.
[0013] Furthermore, the conductive material is acetylene black or Super P.
[0014] Furthermore, the electrolyte is any one of MgSO4 solution, MgCl2 solution and Mg(NO3)2 solution.
[0015] Furthermore, the concentration of the electrolyte is 0.4 M - 0.6 M.
[0016] Furthermore, the diaphragm is any one of glass fiber diaphragm, polypropylene membrane, filter paper diaphragm, and polymer semi-permeable membrane.
[0017] The beneficial effects of this invention are:
[0018] 1. This invention prepares a novel aqueous magnesium ion asymmetric capacitor using cerium ion-doped manganese dioxide composite material and activated carbon as positive and negative electrode materials, respectively, and has the following advantages: First, Ce 3+ First, cerium ions possess high lattice energy, which, after doping, can stabilize the crystal structure of MnO2, suppress phase transformation or sintering at high temperatures, and improve the stability of the material during long-term use. Second, cerium doping can suppress the excessive growth of MnO2 grains, thereby obtaining smaller grain size and higher specific surface area, providing more active sites. Third, Ce... 3+ Doping can adjust the valence state distribution of manganese in MnO2 and promote electron transfer.
[0019] 2. The aqueous magnesium ion capacitor prepared by the present invention using cerium ion-doped manganese dioxide composite material has an increased discharge time of about 4234 seconds after cerium doping, and a specific capacitance of up to 254.64 F / g, which is about 1.9 times greater than that of the original MnO2.
[0020] 3. This invention uses a cerium ion-doped manganese dioxide composite material as the positive electrode and activated carbon as the negative electrode to construct an electrode assembly. This method features a simple synthesis process, convenient device assembly, and advantages of being environmentally friendly and low-cost, demonstrating good sustainability. This energy storage device has broad application prospects in the field of green energy conservation and is expected to become an ideal environmentally friendly energy storage device in the future.
[0021] 4. The cerium ion-doped manganese dioxide composite material prepared in this invention uses original synthetic materials that are low in cost, environmentally friendly, recyclable, and non-toxic. The prepared cerium ion-doped manganese dioxide composite material not only has a high specific capacitance but also exhibits excellent compatibility with the selected electrolyte, which is beneficial for improving the overall electrochemical performance of the device. Attached Figure Description
[0022] Figure 1 This is the XRD pattern of the MnO2 and Ce-MnO2 composite materials prepared in this invention.
[0023] Figure 2 This is the SEM spectrum of the Ce-MnO2 composite material prepared in this invention.
[0024] Figure 3 This is a time-voltage diagram of the asymmetric aqueous magnesium ion capacitor assembled with Ce-MnO2 composite material and activated carbon prepared in this invention.
[0025] Figure 4 This is a comparison diagram of the specific capacitance of the asymmetric aqueous magnesium ion capacitor assembled with Ce-MnO2 composite material and activated carbon prepared in this invention and the original asymmetric aqueous magnesium ion capacitor assembled with MnO2 and activated carbon. Detailed Implementation
[0026] Example 1: A cerium ion-doped manganese dioxide composite material (Ce-MnO2)
[0027] I. The preparation method is as follows:
[0028] 0.4 g potassium permanganate, 0.0783 g manganese sulfate monohydrate, and 0.025 g cerium acetate were added sequentially to 40 mL of deionized water. After magnetic stirring for 1 h, the mixture was fully dissolved. The resulting mixture was then transferred to a high-pressure reactor lined with polytetrafluoroethylene (PTFE) and subjected to a hydrothermal reaction at 160 °C for 16 h. After natural cooling to room temperature, the mixture was centrifuged, washed three times with deionized water and ethanol, and dried in a vacuum drying oven at 60 °C for 12 h to obtain the target Ce-MnO2 composite material.
[0029] II. Comparative Example – The preparation method of raw manganese dioxide is as follows:
[0030] 0.4 g of potassium permanganate and 0.0783 g of manganese sulfate monohydrate were added sequentially to 40 mL of deionized water. After stirring magnetically for 1 h, the mixture was fully dissolved. The resulting mixture was then transferred to a high-pressure reactor lined with polytetrafluoroethylene and subjected to a hydrothermal reaction at 160 °C for 16 h. After cooling naturally to room temperature, the mixture was centrifuged, washed three times with deionized water and ethanol, and dried in a vacuum drying oven at 60 °C for 12 h to obtain the target MnO2 material.
[0031] III. Testing
[0032] Figure 1 This is the XRD pattern of the cerium ion-doped manganese dioxide composite material prepared in this embodiment. Figure 1 As can be seen, the material obtained after the hydrothermal reaction is a composite material of MnO2 (PDF#80-1098) and Ce-MnO2. After cerium doping, the XRD pattern of the sample did not show significant changes, the peak intensity weakened, and the shift of individual peaks indicated that cerium ions were successfully doped into MnO2.
[0033] Figure 2 This is the SEM spectrum of the cerium ion-doped manganese dioxide composite material prepared in this embodiment. Figure 2 As can be seen, the Ce-MnO2 composite material has a regular flower-like shape.
[0034] Example 2: A cerium ion-doped manganese dioxide composite material (Ce-MnO2)
[0035] The preparation method is as follows:
[0036] 0.4 g potassium permanganate, 0.0783 g manganese sulfate monohydrate, and 0.025 g cerium acetate were added sequentially to 40 mL of deionized water. After magnetic stirring for 1 h, the mixture was fully dissolved. The resulting mixture was then transferred to a high-pressure reactor lined with polytetrafluoroethylene (PTFE) and subjected to a hydrothermal reaction at 120 °C for 16 h. After natural cooling to room temperature, the mixture was centrifuged, washed three times with deionized water and ethanol, and dried in a vacuum drying oven at 60 °C for 12 h to obtain the target Ce-MnO2 composite material.
[0037] Example 3: A cerium ion-doped manganese dioxide composite material (Ce-MnO2)
[0038] The preparation method is as follows:
[0039] 0.4 g potassium permanganate, 0.0783 g manganese sulfate monohydrate, and 0.025 g cerium acetate were added sequentially to 40 mL of deionized water. After magnetic stirring for 1 h, the mixture was fully dissolved. The resulting mixture was then transferred to a high-pressure reactor lined with polytetrafluoroethylene and subjected to a hydrothermal reaction at 130 °C for 16 h. After natural cooling to room temperature, the mixture was centrifuged, washed three times with deionized water and ethanol, and dried in a vacuum drying oven at 60 °C for 12 h to obtain the target Ce-MnO2 composite material.
[0040] Example 4: A cerium ion-doped manganese dioxide composite material (Ce-MnO2)
[0041] The preparation method is as follows:
[0042] 0.4 g potassium permanganate, 0.0783 g manganese sulfate monohydrate, and 0.025 g cerium acetate were added sequentially to 40 mL of deionized water. After magnetic stirring for 1 h, the mixture was fully dissolved. The resulting mixture was then transferred to a high-pressure reactor lined with polytetrafluoroethylene (PTFE) and subjected to a hydrothermal reaction at 140 °C for 16 h. After natural cooling to room temperature, the mixture was centrifuged, washed three times with deionized water and ethanol, and dried in a vacuum drying oven at 60 °C for 12 h to obtain the target Ce-MnO2 composite material.
[0043] Example 5: A cerium ion-doped manganese dioxide composite material (Ce-MnO2)
[0044] The preparation method is as follows:
[0045] 0.4 g potassium permanganate, 0.0783 g manganese sulfate monohydrate, and 0.025 g cerium acetate were added sequentially to 40 mL of deionized water. After magnetic stirring for 1 h, the mixture was fully dissolved. The resulting mixture was then transferred to a high-pressure reactor lined with polytetrafluoroethylene and subjected to a hydrothermal reaction at 150 °C for 16 h. After natural cooling to room temperature, the mixture was centrifuged, washed three times with deionized water and ethanol, and dried in a vacuum drying oven at 60 °C for 12 h to obtain the target Ce-MnO2 composite material.
[0046] Example 6: A cerium ion-doped manganese dioxide composite material (Ce-MnO2)
[0047] The preparation method is as follows:
[0048] 0.4 g potassium permanganate, 0.0783 g manganese sulfate monohydrate, and 0.025 g cerium acetate were added sequentially to 40 mL of deionized water. After magnetic stirring for 1 h, the mixture was fully dissolved. The resulting mixture was then transferred to a high-pressure reactor lined with polytetrafluoroethylene (PTFE) and subjected to a hydrothermal reaction at 170 °C for 16 h. After natural cooling to room temperature, the mixture was centrifuged, washed three times with deionized water and ethanol, and dried in a vacuum drying oven at 60 °C for 12 h to obtain the target Ce-MnO2 composite material.
[0049] Example 7: A cerium ion-doped manganese dioxide composite material (Ce-MnO2)
[0050] The preparation method is as follows:
[0051] 0.4 g potassium permanganate, 0.0783 g manganese sulfate monohydrate, and 0.025 g cerium acetate were added sequentially to 40 mL of deionized water. After magnetic stirring for 1 h, the mixture was fully dissolved. The resulting mixture was then transferred to a high-pressure reactor lined with polytetrafluoroethylene and subjected to a hydrothermal reaction at 180 °C for 16 h. After natural cooling to room temperature, the mixture was centrifuged, washed three times with deionized water and ethanol, and dried in a vacuum drying oven at 60 °C for 12 h to obtain the target Ce-MnO2 composite material.
[0052] Example 8: A cerium ion-doped manganese dioxide composite material (Ce-MnO2)
[0053] The preparation method is as follows:
[0054] 0.4 g potassium permanganate, 0.0783 g manganese sulfate monohydrate, and 0.025 g cerium acetate were added sequentially to 40 mL of deionized water. After magnetic stirring for 1 h, the mixture was fully dissolved. The resulting mixture was then transferred to a high-pressure reactor lined with polytetrafluoroethylene and subjected to a hydrothermal reaction at 190 °C for 16 h. After natural cooling to room temperature, the mixture was centrifuged, washed three times with deionized water and ethanol, and dried in a vacuum drying oven at 60 °C for 12 h to obtain the target Ce-MnO2 composite material.
[0055] Example 9: Application of cerium ion-doped manganese dioxide composite material as a positive electrode material in aqueous magnesium ion capacitors.
[0056] I. The preparation method is as follows:
[0057] 1. Preparation of the positive electrode:
[0058] After mixing 40 mg of the Ce-MnO2 composite material obtained in Example 1 with 5 mg of polyvinylidene fluoride and 5 mg of Super P, a small amount of NMP was added dropwise as a dispersion liquid to ensure that the polyvinylidene fluoride and other substances were thoroughly ground and mixed evenly. The resulting slurry was then directly coated onto a substrate carbon paper and dried in a vacuum drying oven at 60 °C. After being removed, the slurry was punched using a punching machine to obtain a positive electrode sheet coated with the Ce-MnO2 composite material.
[0059] 2. Preparation of the negative electrode:
[0060] After mixing 40 mg of activated carbon with 5 mg of polyvinylidene fluoride and 5 mg of Super P evenly, a small amount of NMP was added dropwise as a dispersion. After mixing evenly, the resulting slurry was directly coated onto a substrate carbon paper and dried in a vacuum drying oven at 60 °C for 12 h. After removal, the slurry was punched using a punching machine to obtain a negative electrode sheet coated with activated carbon.
[0061] 3. Preparation of aqueous magnesium ion capacitors:
[0062] The negative electrode sheet coated with activated carbon is placed in the center of the negative electrode shell, then the separator is placed in the negative electrode shell, and 150 µL of 0.5 M MgSO4 electrolyte is added. Then the positive electrode sheet coated with Ce-MnO2 composite material is brought into contact with the wetted separator. Finally, the gasket and spring are placed in, and the battery is assembled into a CR2032 button cell using a battery packaging machine to obtain an asymmetric aqueous magnesium ion capacitor Ce-MnO2 / / AC.
[0063] In addition, the comparative example uses MnO2 as the positive electrode material to prepare an asymmetric aqueous magnesium ion capacitor MnO2 / / AC assembled from raw MnO2 and activated carbon according to the above steps.
[0064] II. Performance Testing:
[0065] Figure 3 This is a time-voltage diagram of an asymmetric aqueous magnesium ion capacitor assembled from the cerium ion-doped manganese dioxide composite material and activated carbon prepared in this invention. Figure 3 As can be seen, the discharge time of the cerium ion-doped manganese dioxide composite material obtained in Example 1 is significantly longer than that of the original single manganese-based material, increasing by approximately 4234 seconds.
[0066] Figure 4 This is a comparison chart of the specific capacitance of the asymmetric aqueous magnesium ion capacitor assembled with cerium ion-doped manganese dioxide composite material and activated carbon prepared in this invention, and the original asymmetric aqueous magnesium ion capacitor assembled with manganese dioxide and activated carbon. Figure 4 As can be seen, the cerium ion-doped manganese dioxide composite material obtained in Example 1 has a specific capacitance of up to 254.64 F / g compared to the original single manganese-based material, which is about 1.9 times higher than that of the original manganese dioxide.
[0067] III. The Influence of Cerium Ion-Doped Manganese Dioxide Composite Materials Obtained at Different Hydrothermal Temperatures on the Performance of Asymmetric Aqueous Magnesium Ion Capacitors as Cathode Materials
[0068] Examples 1-8 describe Ce-MnO2 composite materials obtained at hydrothermal temperatures of 120℃-190℃. These Ce-MnO2 composite materials obtained under different conditions were used as positive electrode materials, and asymmetric aqueous magnesium ion capacitors were assembled using the same method as in (I). Their electrochemical performance was then tested. Comparative analysis shows that the device prepared using the Ce-MnO2 composite material obtained in Example 1 exhibits the best performance.
Claims
1. A cerium ion-doped manganese dioxide composite material, characterized in that, The preparation method of the cerium ion-doped manganese dioxide composite material includes: adding potassium permanganate, manganese sulfate monohydrate and cerium acetate to deionized water, stirring to dissolve and disperse evenly, transferring the resulting mixed solution to a high-pressure reactor lined with polytetrafluoroethylene for hydrothermal reaction, centrifuging and washing, and drying to obtain the cerium ion-doped manganese dioxide composite material Ce-MnO2.
2. The cerium ion-doped manganese dioxide composite material according to claim 1, characterized in that, By mass ratio, potassium permanganate: manganese sulfate monohydrate: cerium acetate = (15 - 17): (2 - 4):
1.
3. The cerium ion-doped manganese dioxide composite material according to claim 1, characterized in that, The hydrothermal reaction is carried out at a temperature of 120 ℃ - 190 ℃ for a time of 15 h - 17 h.
4. The application of the cerium ion-doped manganese dioxide composite material according to any one of claims 1-3 as a positive electrode material in an aqueous magnesium ion capacitor.
5. The application according to claim 4, characterized in that, The method includes the following steps: (1) Preparation of positive electrode: After the cerium ion doped manganese dioxide composite material Ce-MnO2 is mixed evenly with binder and conductive material, a small amount of NMP is added as a dispersion liquid. After mixing evenly, the resulting slurry is directly coated on the substrate and dried to obtain a positive electrode sheet coated with Ce-MnO2. (2) Preparation of negative electrode: After the activated carbon, binder and conductive material are mixed evenly, a small amount of NMP is added as a dispersion liquid. After mixing evenly, the resulting slurry is directly coated on the substrate and dried to obtain a negative electrode sheet coated with activated carbon. (3) Preparation of aqueous magnesium ion capacitor: The negative electrode plate coated with activated carbon is placed in the center of the negative electrode shell, then the separator is placed in the negative electrode shell and electrolyte is added to fully wet the separator. Then the positive electrode plate coated with Ce-MnO2 is placed in contact with the wetted separator. Finally, the gasket and spring are placed in and sealed to obtain an aqueous magnesium ion capacitor.
6. The application according to claim 5, characterized in that, The binder is carboxymethyl cellulose or polyvinylidene fluoride.
7. The application according to claim 5, characterized in that, The conductive material is acetylene black or Super P.
8. The application according to claim 5, characterized in that, The electrolyte is any one of MgSO4 solution, MgCl2 solution and Mg(NO3)2 solution.
9. The application according to claim 8, characterized in that, The concentration of the electrolyte is 0.4 M - 0.6 M.
10. The application according to claim 5, characterized in that, The diaphragm is any one of glass fiber diaphragm, polypropylene membrane, filter paper diaphragm, and polymer semi-permeable membrane.