Beaded manganese oxide (Mn2O3) nanofibers: preparation and application for capacitive energy storage

Abstract

Here, we report a surfactant-free electrospinning based method for the synthesis of beaded manganese oxide (Mn₂O₃) nanofibers and their application as supercapacitor electrodes. The beaded morphology of the fibers was confirmed through electron microscopic analysis. The highly crystalline nature and lattice strain of the fibers were verified by X-ray diffraction analysis while the chemical composition of the fibers was studied by using X-ray photoelectron and Raman spectroscopy. The electrochemical properties of the Mn₂O₃ nanofiber electrode were investigated using cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy in a 0.5 M Na₂SO₄ aqueous electrolyte. The specific capacitance of the Mn₂O₃ beaded nanofibers was found to be 358 F g⁻¹ at a current density of 0.5 A g⁻¹. Lattice strain-induced ionic and electronic defects enhanced the surface properties of the Mn₂O₃ nanofibers, thereby improving their electrochemical properties.