▎ 摘　　要

Utilization of carbonaceous waste into energy storage applications not only solves the problem of waste man-agement but also promotes the circular economy. Any carbonaceous material with a high surface area and sheet -like nanostructure facilitates fast-ion transport due to which it can act as a suitable candidate for the electrode material in Supercapacitors. This work reports the preparation of few-layer graphene nanosheets from fruit waste: kinnow peel waste (KPW) for the first time, via two-step pyrolysis with activation using KCl as the activating agent followed by probe sonication. The confirmation of few-layer graphene (FLG) nanosheets from KPW was done with the help of RAMAN, XRD, FT-IR, SEM, and TEM. The high surface area with the presence of both the meso and micropores in synthesized FLG nanosheets was confirmed with the help of BET. The KPW-derived few-layer graphene (KPW-FLG) nanosheets were further investigated for high-performance super -capacitors by fabricating three different supercapacitor devices (SCs); SC-1, SC-2, and SC-3 corresponded to 6 M KOH, 1 M H2SO4 and 1 M H3PO4 respectively. The ideal and reversible capacitive behavior of the fabricated SC devices was analyzed with the help of Cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) techniques. The SC-2 displayed the highest gravimetric specific capacitance (Cs) value of 642 F/g at a scan rate of 5 mV/s in a 1 M H2SO4 electrolyte with the highest energy density of 48.9 Wh/Kg and better power density of 629.5 W/Kg. Our study revealed that the KPW-FLG can be used as the potential candidate for electrode material in fabricating the high-performance supercapacitor which showed the best results in capacitance, charge -discharge, cyclic stability, and energy density with 1 M H2SO4 electrolyte.