Reduced graphene oxide/ Sr2Co2O5 composites as electrode material for supercapacitors

Composites of transition metal-oxides with graphene have grown as potential materials for electrodes, for supercapacitor applications. In this work, Sr2Co2O5 with different percentages of reduced graphene oxide (rGO) (0-15 %) has been prepared by a simple solvothermal technique. The electrochemical performance of composites is examined in comparison with pure Sr2Co2O5. Structural analysis exhibited the orthorhombic structure of Sr2Co2O5 whereas the morphological investigations revealed a variety of morphology for different compositions. The presence of all elements in the parent and derived compositions according to their stochiometric formula is ascertained by energy dispersive X-ray spectroscope. The investigations of electrochemical characteristics revealed the dominant pseudocapacitance behavior in the cyclic voltammetry technique. The value of specific capacitance, energy density, and power density are computed from GCD data. The Sr2Co2O5@15%rGO exposes the highest specific-capacitance of 230.95 F/g at the current density of 0.625 A/g, and high energy and power densities having values of 76.58 Wh/kg and 4.94 W/kg respectively at 12.5 A/g. The solution resistance and ion transportation resistance are examined through electrochemical impedance spectroscopy which exhibits the potential of these composites for supercapacitor electrode material.