Investigation of Supercapacitive Behaviour of Electrodeposited Cobalt Oxide Thin Film by Potentiostatic Mode

Abstract

Cobalt oxide films were prepared potentiostatically on stainless steel substrates. The as-deposited Co3O4 films were annealed at 400 °C, 500 °C, 600 °C and were analyzed. The structural analysis of films was carried out by X-ray diffraction technique and wettability parameters by Contact angle measurements at different annealed temperatures. The electrochemical supercapacitive behaviour of Cobalt oxide thin film was studied through Electrochemical properties using cyclic voltammetry and galvanostatic charge-discharge analysis which were carried out in 1 M aqueous KOH, 1 M aqueous NaOH and 1 M aqueous Na2SO4 electrolytes at a scan rate of 5 mV∙s – 1 with a three-electrode cell at different annealed temperatures. The film exhibited maximum specific capacitance of 284.4 Fg – 1 at a scan rate of 5 mV∙s – 1, specific energy 4.325 Whkg – 1, specific power 3 kWkg – 1 and coulomb efficiency 53.75 % in 1 M Na2SO4 electrolyte at optimized annealed temperature of 500 °C. In 1 M KOH electrolyte specific capacitance of Cobalt oxide electrode was 182.03 Fg – 1 at a scan rate 5 mV∙s – 1, specific energy 3.570 Whkg – 1, specific power 2.00 kWkg – 1 annealed at 500 °C. In 1 M NaOH electrolyte, annealed at 500 °C, the specific capacitance of Cobalt oxide electrode was 176.33 Fg – 1 at a scan rate 5 mVs – 1, specific energy 4.37 Whkg – 1, specific power 2.33 kWkg – 1.