Advanced supercapattery materials: hydrothermally synthesized niobium sulfide/reduced graphene oxide composites

Supercapattery combines batteries with the advantages of supercapacitors. The hydrothermal method was employed to synthesize niobium sulfide (NbS), then doped them with reduced graphene oxide (rGO). A total surface area of 15.50 m2 /g was identified for NbS/N-GQDs by Brunauer-Emmett-Teller (BET). The composite niobium sulfide (NbS/rGO) displayed 858 Cg-1 regarded as a higher specific capacity (Cs) in the threeelectrodes assembly. To construct an asymmetric supercapacitor, battery-graded NbS/rGO was used as the +ve as well as AC as the -ve terminals respectively. The Nbs/rGO//AC demonstrated maximum Cs of 190 Cg-1 besides power and energy densities of 1510 WKg-1 and 34.6 WhKg-1 respectively. 90% of the initial capacity of NbS/rGO//AC remained after 5000 cycles. Future energy storage systems can use NbS/rGO as a nanostructured electrode due to its remarkable electrochemical efficiency.