Chemical synthesis of spinel cobalt ferrite (CoFe2O4) nano-flakes for supercapacitor application

► The first time preparation of cobalt ferrite material in thin film form, using chemical method at low temperature. ► A nano-flake like morphology of the cobalt ferrite thin film. ► An application of the film as an electrode in supercapacitor cell. The present paper reveals the formation of cobalt ferrite (CoFe2O4) thin film on stainless steel substrate by simple chemical route from an alkaline bath containing Co2+ and Fe2+ ions. The films are characterised for structural, surface morphological and FT-IR properties. The XRD and FT-IR studies revealed formation of single phase of CoFe2O4. The formation of nano-flakes-like morphology is observed from scanning electron microscope. The electrochemical behaviour of CoFe2O4 film has been studied using cyclic voltammetry in 1M NaOH electrolyte. The maximum specific capacitance of 366Fg−1 is obtained at the scan rate of 5mVs−1. Using AC impedance technique equivalent series resistance (ESR) value is found to be 1.1Ω.