High performance supercapacitor active electrode material by drop-casting of graphite and graphene synthesized from rice husk

A high performance supercapacitor was produced by synthesizing graphite using froth flotation and graphene from waste rice husk using the doped casting method. The composition of the graphene was kept constant (Gr0.3 g) and the graphite was varied (0.1–0.2 g). The supercapacitor was produced by the doping method. The microstructure, cyclic voltammetry, electrical impendence spectroscopy, and X-ray diffraction were determined. Increasing the concentration of graphite increases the specific capacitance of the graphene/graphite (Gr/G) composite electrode. Enhanced supercapacitors with a specific capacitance of 2842.43Fg⁻¹ at a scan rate of 5 mV/s can be made using 0.2 g graphite doped with 0.3 g graphene. An increase in the surface area of the composite material facilitated fast ion and electron transportation, thereby improving its electrochemical properties. This research has shown that high-quality supercapacitor electrodes may be made from waste rice husk and graphite ore using froth flotation, chemical methods, and doping.