Defect rich Se–CoWS2 as anode and banana flower skin-derived activated carbon channels with interconnected porous structure as cathode materials for asymmetric supercapacitor application

We propose the Se heteroatoms incorporated CoWS2 (Se–CoWS2) as anode and banana flower skin-derived activated carbon (BFS-AC) as cathode for energy storage application. Herein, the Se–CoWS2 was prepared by using hydrothermal and selenization methods, while the BFS-AC was prepared by following the carbonization method. The formation of anode and cathode active materials were confirmed by using various analytical techniques. In electrochemical studies, the Se–CoWS2 modified nickel foam (NF) exhibits the lower charge transfer resistance (Rct) and higher specific capacity (452 C/g at current density of 0.5 A/g) and long term stability (96.15% retention after 2,000th cycles). Fortunately, the fabricated asymmetric device (Se–CoWS2//BFS-AC) has delivered a satisfactory energy density of 107.87 W h kg−1 at a power density of 1600 W kg−1. And also, the device retains its 95.33% of Coulombic efficiency up to 3000 continuous charge/discharge cycles. In light emitting diode (LED) tests, the device lights up the LED around 30 min, which indicates the practicability of proposed asymmetric device. Finally, this study addresses that the heteroatom incorporation with metal chalcogenides can be one of the suitable methods to prepare the electrode materials with necessary electrochemical properties. In addition, the biomass-derived carbon can facilitate better charge balance in asymmetric configuration.