High-performance solid-state asymmetric Supercapacitor based on α-Fe₂O₃/r-GO/GCN composite electrode material for energy storage application

Herein, a 3D/2D/2D of α-Fe₂O₃/r-GO/GCN composites were synthesized by combined reflux condensation and sonochemical-assisted wet-impregnation techniques. The physicochemical properties of the prepared materials were inspected by various analytical techniques. Morphology analysis techniques of different electron microscopes were employed to confirm the rhombohedral (3D) and two-dimensional (2D) sheets' morphology. The electrochemical behaviour of the as-synthesised electrode materials was assessed for use in a redox electrolyte-based energy storage system. Electrochemical measurements in a 6M KOH solution revealed that the electrode exhibited good supercapacitive behaviour. The 3D/2D/2D -α-Fe₂O₃/r-GO/GCN composite had a higher capacitance rate of roughly 810 F g⁻¹ than α-Fe₂O₃ nanoparticles at 1Ag⁻¹. From cyclic stability, ternary composite has good cyclic retention (98.9%) after 10,000 cycles at 10 Ag⁻¹. The surface characteristics of metal oxide nanostructures and the efficient conductive networks of r-GO and GCN sheets are primarily responsible for the ternary α-Fe₂O₃/r-GO/GCN composite's superior electrochemical performance. Asymmetric supercapacitor (ASC) devices were constructed using 3D/2D/2D anodic material and activated carbon as a cathode material with a power density of 929 Wkg⁻¹, energy density of 40 WhKg⁻¹, and 92 % of capacity retention.