Supercapacitive Performance of Electrodeposited Cobalt Oxide Electrode

Abstract

AbstractMetal oxide based supercapacitors have emerged as one of the most elegant storage systems with exclusive characteristics with high power density and long‐term cycling stability. Cobalt oxide (Co3O4) has particularly obtained rising interest due to their natural abundance, environment friendly, low cost, and high specific capacitance. Co3O4 thin film electrodes were successfully deposited via a simple and easy galvanostatic electrodeposition technique on to cheap stainless steel substrate. As‐deposited thin films were heated at 500 °C for its conversion to Co3O4. These films were characterized for XRD, SEM, and CA to understand the structural, morphological and wettability properties of Co3O4 electrode. By using cyclic voltammetry, charge‐discharge study and supercapacitive behavior of Co3O4 electrode were examined. The Co3O4 electrode showed maximum specific capacitance of 554 F g–1 at 5 mV s–1 in 1 m NaOH electrolyte. The specific energy, specific power, and coulombic efficiency showed 16.32 Wh kg–1, 11.72 kW kg–1, and 94.2%, respectively. The results clearly evidenced that those devices based on Co3O4 electrodes are promising energy storage devices for microelectronic applications as well as high energy supercapacitors.