Microwave-assisted synthesis of cobalt-manganese oxide for supercapacitor electrodes

Abstract

Multi-electron surface facilitating swift movement of electrons on the surface of the electrode during the faradaic charge storage reaction establish transition metal oxides as desired electrode materials for supercapacitor application. Cobalt oxide and manganese oxide are electrochemically active materials whose theoretical capacitance is not yet achieved due to certain parameters which are expected to be resolved when they are put together as a single material. In the present work, cobalt manganese oxide, a mixed transition‐metal oxide is prepared via a facile microwave-assisted method. The crystalline phases, vibrational properties and surface morphology of the synthesized oxide are examined. The electrochemical properties of the synthesized oxide are explored in 1 M KOH aqueous electrolyte within a potential window of −0.2 V to 0.7 V. The prepared pseudocapacitive mixed transition metal oxide has a specific capacitance of 323 F g−1 at 0.5 A g−1 current density with 103.9% capacitance retention after 2000 consecutive redox cycles. The enhanced electrochemical properties of the material suggest that the prepared cobalt manganese oxide can be a note-worthy supercapacitor electrode material.