Fabrication of activated carbon electrodes derived from peanut shell for high-performance supercapacitors

In this work, the activated carbon (AC) is derived from the waste material of peanut shells. The obtained activated carbon has been synthesized using the chemical activation process via impregnation with NaOH at various proportions (1:2 and 1:3). The structural, morphological, and electrochemical properties of obtained AC are examined by X-ray diffraction (XRD), BET surface analysis, scanning electron microscopy (SEM), and electrochemical techniques. The resulting AC shows the enhancement in specific surface area (SSA) from 584 to 735 m2/g at 1:2 ratio and 826 m2/g at 1:3 ratio after the activation process. The electrodes are fabricated using derived activated carbon for electrochemical characterization. It has been observed through cyclic voltammetry and galvanostatic charge–discharge measurements that 1:3 NaOH-activated samples reveal the maximum value of specific capacitance (263 F/g at 10 mV/s and 290 F/gat 0.2A/g). The sample also conveys the pre-dominant ~ 98% of efficiency from 400 to 1000th cycle with fast and almost constant capacitance. The electrochemical impedance spectroscopy (EIS) result suggests the pure capacitive nature of the sample and indicates the dominating electric double-layer capacitive (EDLC) behavior. The obtained results demonstrate that the peanut shell–derived activated carbon is a potential candidate as an electrode material for supercapacitors.