Electrochemical evaluation of hybrid La2CoCrO6/Co3O4/rGO composite for enhanced supercapacitor performance

Abstract

The present work focuses on the synthesis of hybrid La₂CoCrO₆/Co₃O₄/rGO composite via solvothermal technique for supercapacitor application. X-ray diffraction, field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, Brunauer-Emmett-Teller (BET), and Barrett-Joyner-Halenda analyses are employed to assess phase structure, morphology, chemical state, surface area, and porosity of synthesized materials, respectively. The formation of mesoporous spheres is confirmed through FESEM and BET analysis. The inclusion of redox additive KMnO₄ in KOH electrolyte enhances the accessibility of electrochemical sites in the mesoporous spheres of the La₂CoCrO₆/Co₃O₄/rGO electrode, resulting in excellent charge storage. Electrochemical analysis of the La₂CoCrO₆/Co₃O₄ exhibits specific capacitance of 633.2 F/g at 2 A/g in a redox electrolyte (6 M KOH + 0.05 M KMnO₄) with capacitive retention of approximately 81 % over 5000 cycles. Furthermore, the addition of rGO improves the overall performance of La₂CoCrO₆/Co₃O₄/rGO composite (763.9 F/g at 2 A/g with capacitive retention of approximately 86 %). The electrochemical analysis of hybrid La₂CoCrO₆/Co₃O₄/rGO composite showed improved performance, owing to the synergy of double perovskite (La₂CoCrO₆), cobalt oxide (Co₃O₄), and reduced graphene oxide (rGO). These findings suggest promising applications for the material in advanced energy storage devices.