Different Phase and Morphology Effect of Manganese Oxide on Electrochemical Performance for Supercapacitor Application

Abstract

Nanostructures of manganese oxides are a promising pseudocapacitive electrode material due to its eco-friendly, low cost, and intrinsically high capacity. In this work, we prepared monometallic manganese oxide Mn₃O_4, and MnO₂ using a facile, one-step hydrothermal method at low processing temperature. The structural, morphological, elemental analysis of manganese oxide (Mn₃O₄ nanoparticles (NPs) and one-dimensional MnO₂ nanowires (1-D NWs)) powders confirmed from XRD, TEM, SEM, and EDAX techniques. The prepared materials have the same crystal structure with different phase and morphology. The morphology information of prepared Mn₃O_4, MnO₂ powders visualized from an electron microscope of TEM and SEM techniques as particle and wire type morphology. The electrochemical performance of fabricated individual Mn₃O₄ and MnO₂ @ Ni foam electrodes exhibited specific capacitance around 182 and 243 F/g at a current density of 0.5 A/g from galvanostatic charge–discharge cycles measurement in presence of 1 M KOH compared with 0.5 M KOH electrolyte solution. Also, from these results, the morphology of MnO₂ (NWs) has better specific capacitance than Mn₃O₄ (NPs) in 1 M KOH electrolyte solution.