Copper phosphate-assisted silkworm waste-derived biochar composite for energy storage application

Biochar has gained widespread recognition as a potential material for meeting global demands for sustainable energy. The current study revealed an efficient method for making biochar from waste silk worms. This synthesized biochar (SBC) was doped with hydrothermally synthesized copper phosphate (CPh) in various ratios. The prepared materials are analyzed by advanced physical characterisations. The synthesized SBC/CPh composites materials were used for energy storage (supercapacitor) application. The electrochemical performance of the materials was investigated by galvanostatic charge discharge (GCD), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) studies. The prepared composite materials have excellent specific capacitance of 243 F/g at 0.5 A/g of current density with good cyclic stability (84% after 4000 cycles). In addition, the calculated energy density and power density of the prepared composite material show 30.3 Wh kg −1 and 225 W kg −1, respectively, at the current density of 0.5 A/g. This study highlights an efficient and low-cost methodology for the utilization of silkworm waste for energy storage application. Graphical Abstract