Controlled synthesis of three-phase NixSy/rGO nanoflake electrodes for hybrid supercapacitors with high energy and power density

A three-phase nickel sulfide (NiS-Ni3S2-Ni3S4)/reduced graphene oxide was designed and successfully prepared, which delivered high specific capacity (807 C g−1 at 1 A g−1), and good rate capability. Importantly, a hybrid supercapacitor device was also fabricated based on the nickel sulfide/graphene positive electrode and graphene negative electrode, which demonstrated a high energy density and good cycling stability. Two such devices connected in series could power 37 commercial LEDs, demonstrating its great potential application in energy storage systems.181