S-doped activated mesoporous carbon derived from the Borassus flabellifer flower as active electrodes for supercapacitors

Abstract

A successful transformation of Borassus flabellifer flower into activated carbon (AC) with the highest intakes of sulfur (S) contents in the S-doped AC process turned the materials to be a potential candidate for supercapacitor applications. The suitable proportion of KOH during activation and the effect of thiourea as a precursor were other major factors in the transformation process. Many experiments have left the possibility of the effects of the high S content of the materials unnoticed; this attempt explored the result of the high content S-doped mesoporous AC via hydrothermal method. Moreover, doping sulfur and oxygen functionalities on its carbon matrix helps to improve its electrochemical properties. HRSEM/EDX with elemental mapping evidenced the porous sheetlike morphologies. XRD, Raman spectra and nitrogen adsorption/desorption isotherm analysis were studied. The reported specific surface area of the AC (PM6) is found to be 474.99 m2/g with the highest 10 wt% of S at an activation temperature of 600 °C for 1 h with 30 wt% of KOH. This S-doped AC exhibits high specific capacitance of 275 F/g at a current density of 1 A/g. The symmetric supercapacitors cell (SSC) exhibited specific capacitance of 137.7 F/g at 1 A/g, with enhanced superior cycling stability with 95.4% retention after 3000 cycles at 1 A/g. The SSC delivers energy density of 9.345 Wh/kg and power density of 687 W/kg.