Three-Dimensional Hierarchical Porous Carbons Derived from Betelnut Shells for Supercapacitor Electrodes

Electrochemical energy storage (EES) systems are attracting research attention as an alternative to fossil fuels. Advances in the design and composition of energy storage materials are particularly significant. Biomass waste-derived porous carbons are particularly suitable for use in EES systems as they are capable of tuning pore networks from hierarchical porous structures with high specific surface areas. These materials are also more sustainable and environmentally friendly and less toxic and corrosive than other energy storage materials. In this study, we report the creation of a three-dimensional hierarchical porous carbon material derived from betelnut shells. The synthesized three-dimensional (3D) hierarchical porous carbon electrode showed a specific capacitance of 290 F g^-1 using 1 M KOH as an electrolyte at a current density of 1 A g^-1 in three-electrode systems. Moreover, it offered a high charge/discharge stability of 94% over 5000 charge-discharge cycles at a current density of 5 A g^-1. Two-electrode symmetric systems show a specific capacitance of 148 F g^-1, good cyclic stability of 90. 8% for 5000 charge-discharge cycles, and high energy density of 41 Wh Kg^-1 at the power density of 483 W Kg^-1 in aqueous electrolyte.