Chemically synthesized copper sulfide nanoflakes on reduced graphene oxide for asymmetric supercapacitors

Abstract

The present work describes the deposition of coppersulfide (Cu2S) nanoflakes onto reduced graphene oxide (rGO) on three dimensional (3D) nickel foam byinexpensive chemical methods. The nanohybrid structure exhibitedexcellent surface area (41.67 m2 g−1) with a porous structure (pore size 22.8 nm) and good electrical conductivity with a maximum specific capacitance of 1264 F g−1 at a scan rate of 5 mV s−1. The Cu2S@rGOcomposite exhibits a significantlyhigher specific capacitance. The nanohybrid structure showed outstandingcycling stability of 94 % after 10000cycles. The asymmetric supercapacitor (ASC) device, Cu2S@rGO//rGO exhibited a maximumspecific capacitance of 135 F g−1 withhighenergy and power densities of 50 Wh kg−1, and 7000 W kg−1, respectively.