Optimized Charge Dynamics of Sr2Fe2O5/rGO Composite Electrodes: Redefining Supercapacitor Efficiency

Abstract

Mixed transition metal oxides have become highly effective electrode materials due to their remarkable cyclic stability and improved capacitance, which has consequently led them to display exceptional electrochemical performance. In this work, a facile synthesis of Sr2Fe2O5/reduced graphene oxide composites was carried out through a solvothermal technique to investigate the electrochemical performance. X-ray diffraction patterns confirmed the cubic perovskite structure of Sr2Fe2O5. The morphological analysis revealed well-defined grains with sharp boundaries, having uniformly distributed porous regions. The stoichiometric ratios of sample compositions were confirmed using elemental analysis. The electrolyte employed for the electrochemical characterizations was 1 M potassium hydroxide (KOH), carried out using three-electrode cell. The composite sample Sr2Fe2O5/15% reduced graphene oxide showed excellent electrochemical performance compared to other samples. It demonstrated a maximum specific capacitance of ∼360.29 F g−1 at a lower scan rate of 0.01 V s−1, as observed using cyclic voltammetry. The electrochemical analysis of this electrode through the GCD system has a high value of capacitance ∼1110 F g−1 followed by a high energy density value of ∼32.76 Wh kg−1, respectively. The Nyquist plot revealed less barrier to charge transfer. Therefore, the comprehensive investigation of this electrode material suggested that this as-synthesized composite could be utilized in high-performance energy storage devices.