An Assay of Electrodeposited Cobalt Oxide Thin Film as a Supercapacitor Electrode

Abstract The present research work is a humble effort to synthesize cobalt oxide supercapacitive electrode by electrodeposition method via potentiostatic mode of thin film deposition. The cobalt hydroxide material is deposited on stainless steel substrate at room temperature and annealed at 500°C to form cobalt oxide thin film electrode. The structural, morphological, and wettability investigation of the as‐deposited cobalt oxide thin film electrode is done by XRD‐analysis, SEM characterization, and contact angle measurement, respectively. The supercapacitive properties are investigated in aqueous 1M Na 2 SO 4 electrolyte by cyclic voltametry and galvanostatic charge–discharge analysis. The results of the investigations are maximum specific capacitance of 284.4 F g −1 at a scan rate 5 mV s −1 , specific energy 4.325 Wh kg −1 , specific power 3 kW kg −1 , and Coulomb efficiency 53.75%. The results so obtained promote cobalt oxide to be a challenging material for energy storage devices and supercapacitor applications.