3D flower-like CoNi2S4 grown on graphene decorated nickel foam as high performance supercapacitor

Abstract

3D Flower-like CoNi2S4 is in situ grown on 3D graphene decorated nickel foam current collector as high performance supercapacitor. After the nickel foam is decorated by graphene using CVD method, then the flower-like CoNi2S4 is grown using two step hydrothermal processes. The structural characterizations indicate a uniform and numerous 3D flower-like CoNi2S4 anchored on graphene decorated nickel foam. The flower-like CoNi2S4 directly grown on graphene decorated nickel foam avoids the use of polymer or conductive additive binder which commonly adds in extra contact resistance and dead sites. In addition, the presence of graphene between CoNi2S4 and nickel foam can effectively improve ion/electron transportation and also provide large surface area with regular frame work for anchoring of flower-like CoNi2S4. Using these advantages the as-synthesized electrode exhibits a high areal capacitance of 6.528F/cm2 at current density of 6mA/cm2; excellent cycling stability of 85% after 3500cycles of charge discharge by applying current density of 20mA/cm2 and good rate capability of 71% as current increased from 6 to 60mA/cm2. Such impressive results suggest promising applications of flower-like CoNi2S4 supported on graphene decorated nickel foam as high-performance electrodes for supercapacitors.