Optimizing sponge-like activated carbon from Manihot esculenta tubers for high-performance supercapacitors

Abstract

Activated carbon plays a crucial role in enhancing supercapacitor performance by optimizing parameters such as surface area, pore structure, and morphology. This study investigates activated carbon derived from Manihot esculenta tubers, which offers a promising, sponge-like porous morphology suitable for supercapacitor electrodes. Activated carbon derived from Manihot esculenta tubers was synthesized utilizing chemical activation with varying concentrations of potassium hydroxide (KOH) as the activator 0 M (C-S0), 1 M (AC-S1M), 2 M (AC-S2M), and 4 M (AC-S4M). The AC-S4M sample variant achieved the highest surface area (471.645 m²g⁻¹) and total volume (0.253 cm³g⁻¹). Electrochemical characterization using symmetric coin cell supercapacitors demonstrated excellent specific capacitance of 146.570 Fg⁻¹ at 0.1 Ag⁻¹ in a 6 M KOH aqueous electrolyte. Notably, the highest energy density of 15.525 Whkg⁻¹ at a power density of 174.660 Wkg⁻¹ was achieved. These results underscore the potential of Manihot esculenta tubers-derived activated carbon as a sustainable, high-performance electrode material, advancing environmentally friendly energy storage technologies, which remain interesting for further studies.