Superheated steam-assisted nanoarchitectonics of red calliandra-delivered activated carbon for supercapacitor application

The interaction between the activated carbon pore structure and electrolyte species determines the performance of the supercapacitor. Herein, the pore texture of red calliandra-activated carbon, defined by activation retention and electrochemical behaviour, was investigated by a symmetric supercapacitor using LiPF₆ battery electrolyte. Activated carbon samples were physically activated in superheated steam conditions at 850 °C with different retention times of 30, 60, and 90 min (AC30, AC60, and AC90). Additionally, AC60 was left in the reactor without steam after the final retention (AC60Tt) to observe advanced pore formation. AC60Tt exhibited excellent pore development centered at 2–10 nm (78 %). The logical consequence was the highest iodine adsorption of 901 mg/g and BET area of 587 m²/g. Proximate and FTIR experiments indicated that AC90 had the highest carbon content and CC functional group. AC90 generates an impressive capacitance of 104 F/g at a scan rate of 1 mV/s by the voltammetry technique and 157 F/g, 196 Wh/kg, and 2941 W/g at a potential window of 3.0 V by charge-discharge analysis. AC90 benefits from the highest concentration of mesopores and double bonds, facilitating effective electrode/electrolyte interaction. Finally, the present study reports a facile, economical activated carbon production technique for enhanced supercapacitor performance.