Preparation of Manganese Oxide Nanoparticles with Enhanced Capacitive Properties Utilizing Gel Formation Method

Abstract

Development of efficient and environmentally benign materials is important to satisfy the increasing demand for energy storage materials. Nanostructured transition-metal oxides are attractive because of their variety in morphology, high conductivity, and high theoretical capacitance. In this work, the nanostructured MnO2 was successfully fabricated using a gel formation process followed by calcination at 400 °C (MNO4) and 700 °C (MNO7) in the presence of air. The suitability of the prepared materials for electrochemical capacitor application was investigated using graphite as an electrode substrate. The chemical, elemental, structural, morphological, and thermal characterizations of the materials were performed with relevant techniques. The structural and morphological analyses revealed to be a body-centered tetragonal crystal lattice with a nano-tablet-like porous surface. The capacitive performances of the MNO4- and MNO7-modified graphite electrodes were examined with cyclic voltammetry and chronopotentiometry in a 0.5 M Na2SO4 aqueous solution. The synthesized MNO7 demonstrated a higher specific capacitance (627.9 F g–1), energy density (31.4 Wh kg–1), and power density (803.5 W kg–1) value as compared to that of MNO4. After 400 cycles, the material MNO7 preserves 100% of capacitance as its initial capacitance. The highly conductive network of nanotablet structure and porous morphologies of MNO7 are most likely responsible for its high capacitive behavior. Such material characteristics deserve a good candidate for electrode material in energy storage applications.

Investigation on the Electrochemical Activities of Pristine and Cerium doped Manganese Dixide Nanoparticles for Supercapacitor Electrode Materials

“…Doped electrodes showed a monotonic reduction as the current density increases. Hence the generated electrode exhibits electrochemical double layer capacitor behaviour [54]. Among the resultant electrode material, 1% Ce doped MnO2 Sample revealed highest specific capacitance (158.30F/g) at 1A/g.…”

“…5(a-c), it can be seen that all the curves are in rectangular shape and symmetric nature which demonstrated the excel capacitive behaviour and good reversibility of the electrode. When the scan rate is lifted from 10mV/s to higher value, the electrode retains the same CV curve with enlarged area which suggests that the obtained electrode has high charge storage capacity and excellent rate capability [54][55][56]. The specific capacitance can be estimated by the formula mentioned below,…”

Review on Medical Applications of Manganese Oxide (Mn2+, Mn3+, and Mn4+) Magnetic Nanoparticles

“…The ternary oxides are formed by the reaction of alkaline cations (K + and Na + ) with manganese oxides [63]. Siddique et al [64] prepared manganese oxide nanoparticles using the redox reaction of glycerol and potassium, calcined at two different temperatures at 400-700°C. The surface morphology of the MnO 2 calcined at 700°C shows less aggregation than 400°C.…”

MnO/Mn2O3 Aerogels as Effective Materials for Supercapacitor Applications

“…Manganese also exhibits intercalation and deintercalation of electrolyte ions in the electrode material owing to the transition between Mn 4+ /Mn 3+ ions, which leads to enhanced charge storage properties [10]. The various methods used to produce MnO/Mn 2 O 3 include hydrothermal methods, thermal decomposition, pulsed laser deposition, microemulsion, template synthesis, wet chemical methods, electrodeposition, and sol-gel synthesis [11][12][13]. Among these methods, the sol-gel method is of great significance in terms of simplicity and cost-effectiveness [14,15].…”