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

Abstract

Herein, a 3D/2D/2D of a-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 micro-scopes 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-a-Fe2O3/r-GO/GCN composite had a higher capac-itance rate of roughly 810 F g(-1) than a-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 a-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.