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 supercapacitor application. The incorporation of Se into the CoWS2 atomic lattice and the resultant voids and vacancy defect on the basal plane are scrutinized by using the transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) analyses. Moreover, the Brunauer-Emmett-Teller (BET) and field emission scanning electron microscopy (FESEM) analyses confirm the higher specific surface area (972.90 ± 17.27 m2/g) and porous interconnected channels of BFS-AC. In electrochemical studies, the Se-CoWS2 modified nickel foam (NF) exhibits the lower charge transfer resistance (Rct) and higher specific capacitance (821.21 F/g at a current density of 0.5 A/g) than those of CoWS2 and WS2. Thus, Se-CoWS2 anode and BFS-AC cathode-based asymmetric device (Se-CoWS2//BFS-AC) are successfully fabricated and recorded a satisfactory energy density of 60 W h kg-1 at a power density of 1,800 W kg-1. Finally, this study addresses that the heteroatom incorporation with metal chalcogenides can be one of the suitable methods to prepare the active anode electrode materials with necessary electrochemical properties. In addition, the biomass-derived activated carbon can facilitate better charge balancing in the performance of asymmetric supercapacitor device