Natural Kapok fiber-derived two-dimensional carbonized sheets as sustainable electrode material

Natural biomass-derived carbon nanostructures have attracted research interest because of their unique surface and electrochemical properties. The present study embodied the carbonized micro-nano sheets derived from the low-cost natural source Kapok silk fiber. The material was obtained via a facile thermal pyrolysis process. Diffraction analysis showed a broad graphene structure-like peak, indicating the formation of graphene-like carbon nanosheets. Field emission scanning electron microscope (FESEM) and transmission electron microscopic (TEM) images confirmed the presence of fragmented carbon sheets, some of which were folded to form a tube-like structure. Raman study showed the presence of D and G band with the Id/Ig ratio of 0.96 which indicated the formation of few-layered carbon nanosheets. Furthermore, the electrochemical performance was evaluated for lithium-ion battery as well as supercapacitor. A specific capacity of 465 mAh.g^-1 at 0.1 C rate for Li-ion battery and a specific capacitance of 473.61 F.g^-1 for supercapacitor have been obtained with the capacitance retention of 95 %. This study provides insights into a strategy for the sustainable production and utilization of natural fiber-based carbon in energy storage systems.