Boosting supercapacitor performance synergistically with Bi2O3/MnO2:rGO nanocomposites and redox additive electrolyte

Abstract

The contemporary surge in energy demand underscores the imperative for improvements in energy conversion and storage technologies. In response, supercapacitor devices were engineered using nanocomposites (NCs) of Bi2O3/MnO2:rGO (BMR), and their electrochemical performance was systematically documented. The BMR NCs were hydrothermally prepared and their physicochemical characteristics were analyzed. The working electrode was constructed employing BMR NCs, and tested in a three-electrode setup to explore its electrochemical properties using the aqueous electrolytes consisted of 1 M KOH and 0.1 M K4[Fe(CN)6] added 1 M KOH (referred as Redox additive electrolyte - RAE). BMR NCs loaded working electrode exhibited 1441.1 Fg−1 of specific capacitance at 5 mVs−1 in RAE. Subsequently, asymmetrical supercapacitor devices were assembled, incorporating a cathode comprised of BMR NCs modified Ni foam and rGO-loaded Ni foam as an anode. The supercapacitor performances were evaluated using KOH and RAE in a two-electrode setup. The BMR NCs loaded supercapacitors demonstrated 9.42 Whkg−1 and 2100 Wkg−1, of energy and power densities, respectively, in KOH. Obtained energy and power density values were improved to 16.08 Whkg−1 and 2800 Wkg−1, respectively, by the utilization of RAE. Since the synthesized BMR NCs exhibited superior performances in RAE, the suggested combination of BMR NCs and RAE emerged as a more promising option for energy storage applications in real-time.