Borassus flabellifer Fruit Flesh Derived Hierarchical Porous Partly Graphitic Carbon as a Sustainable Electrode for Supercapacitors

The present work provides a straightforward two-step strategy of carbonization, followed by KOH activation, for transforming Borassus flabellifer fruit flesh, one of the cost-effective and sustainable lignocellulose biomass to porous activated carbon for utilization in energy storage systems. The acquired activated Borassus flabellifer fruit flesh (ABFF) carbon exhibits features like high surface area (similar to 1087.8 m(2) g(-1)) with surface functionalities, hierarchical porous morphology (presence of micropores and mesopores), together with some partially graphitic domain, some of the prerequisites for demonstration of excellent electrochemical performance. Taking advantage of the structural features and chemical composition, the ABFF carbon, when assembled in a symmetrical two-electrode configuration, exhibits an impressive specific capacitance of 226 F g(-1) and 159 F g(-1) in 1 M H2SO4 and neat ionic liquid (IL) EMIMBF4 electrolyte. The as-fabricated symmetric device attained a maximum energy density of 8 Wh kg(-1) in the aqueous medium, while an enhanced energy density of 50 Wh kg(-1) was achieved in the nonaqueous medium.

Automated summary

This study presents a simple two-step strategy of carbonization and KOH activation to transform Borassus flabellifer fruit flesh into activated carbon with high surface area and hierarchical porous morphology, showing excellent electrochemical performance. The activated carbon exhibited specific capacitance of 226 F g(-1) in 1 M H2SO4 and 159 F g(-1) in neat ionic liquid EMIMBF4 electrolyte, achieving a maximum energy density of 8 Wh kg(-1) in aqueous medium and 50 Wh kg(-1) in non-aqueous medium.