Organic Material-Derived Activated Carbon for Eco-Friendly Mulberry Paper Supercapacitor

Paper has gained increasing attention as promising flexible substrate for deformable energy storage systems. However, since low mechanical strength and chemical resistance of commercial paper limited its practical application, mulberry paper (MP) has alternatively studied, which exhibits high holocellulose content, hydrophilicity, and strong bonding with active material. Herein, we prepared activated carbon (AC) using a one of common waste, orange peel (OP), and coated it on MP with additional coating of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), thereby, fabricating hybrid-coated MP for supercapacitor. The prepared AC exhibited enlarged surface area from 1.774 to 986.010 m²/g, and increased total pore volume of 0.639 cm³/g. Furthermore, additional coating of pseudocapacitive material enhanced electrochemical performance. Specific areal capacitance increased approximately 2.3 times, especially showing 78.95 ± 3.04 mF/cm² under scan rate of 100 mV/s. Moreover, fabricated electrode exhibited enhanced energy density of 3.01 µW h/cm² at current density of 0.5 mA/cm², thereby, complementing low energy density of electric double layer (EDL) capacitive material. This approach, which combines biomass-derived AC and MP with hybrid PEDOT:PSS coating, presents a promising pathway for next-generation sustainable energy storage systems.