Fabrication of nanoporous carbon constructions derived from young coconut husk fibers for symmetrical supercapacitor applications

Herein, we report the fabrication of young coconut husk fibers into activated carbon to generate nanoporous carbon constructs, including nanosheet-, nanorod- and nanosphere-like constructs. The fabrication of nanoporous carbon was carried out via ZnCl2 impregnation and high-temperature pyrolysis under CO2 protection using young coconut husk fibers (YCHFs). All the fabricated samples exhibited multiple benefits, including a high specific surface area; nanosheet-, nanorod-, and nanosphere-like porous carbon constructions; and high carbon and oxygen contents. The symmetrical supercapacitor device (YCHF-0.5) delivered an optimum gravimetric capacitance of 317 F/g with an excellent gravimetric energy density of 41.74 Wh/kg at a gravimetric power density of 379.47 W/kg. Considering the physico-chemical characteristics and capacitive performance results, this work could represent an essential benchmark for electrode material fabrication with different nanoporous constructs that have excellent gravimetric energy density from green and sustainable agricultural waste precursors for the development of advanced next-generation energy storage technologies.