Cobalt ferrite (CoFe2O4)–activated carbon fabric (ACF) based composite electrode material for supercapacitor application

Abstract

In the present article, rayon based activated carbon fiber/fabric (ACF) has been developed and explored as an active electrode material in combination with metal oxide for ultracapacitor application. Herein, the ACF is derived from rayon-based carbon fabric through activation and carbonization processes in a tubular furnace and prepared composite material of cobalt ferrite (CoFe2O4, Cof) and activated carbon fabric/fiber. The ACF, cobalt ferrite, and electrode material derived thereof are analyzed by FTIR, XPS, BET surface area analyzer, and XRD methods. The surface morphology and composition of prepared composite is examined by FESEM and EDX. The electrochemical properties of Cof-ACF composite are scrutinized by cyclic voltammetry. The composite material produces considerably high electrochemical supercapacitances in the order of 1287 F/g and 788 F/g at a potential sweep rate of 2 mV/s in 0.5 M phosphoric acid and 0.5 M sulphuric acid electrolytes, respectively. The electrochemical behavior of the cobalt ferrite decorated ACF electrode material exhibits a slightly higher energy density (176.98 Wh/kg) in H3PO4 than in H2SO4 (150.79 Wh/kg) electrolyte. The stability (~74 %) of electrode materials is retained even after 3500 cycles of charge/discharge in acid electrolytes. Thus, Cof-ACF composite material could be used as a cost-effective, compact, and light-weight electrode material with enhanced stability and improved performance for ultracapacitor and energy storage device applications in acid electrolytes.