Fabrication of high-performance electric double-layer capacitor using biomass derived activated carbon as electrode and 1,2,4-triazolium based ionic liquid as electrolyte

In this study, 1,4-dipropyl-1,2,4-triazolium hexafluorophosphate ionic liquid is used as an electrolyte, and activated carbon from Borassus flabellifer tree trunk biomass was prepared following our previously reported procedure and used as the electrode material. The objective of this work is to study the novel combination of electrode and electrolyte and analyse the electrochemical performance. The triazolium ionic liquids (ILs) were chosen for their good ionic conductivity and broad electrochemical stability window, which allowed for better ion transport and electrode–electrolyte interactions. Electrochemical studies additionally revealed enhanced ion transport and energy storage capacities, underscoring their promise within supercapacitors. Cyclic voltammograms yielded a specific capacitance of 179.8 F/g and specific capacity of 99.9 mAh/g at 2 mV/s scan rate and a 2 V potential window, with 10.9 Wh/kg and 656.25 W/kg specific energy and specific power, respectively, and 83% cyclic retention of its initial capacitance, demonstrating long-term stability. These results provide a sustainable method for transforming Borassus flabellifer solid waste into high-performing materials for energy storage and restoration of the environment.