(514i) Nanostructured Graphene Composite for Supercapacitor

Graphene materials show great potential for application in energy storage applications, in which every carbon atom is on the surface.  When incorporated with appropriate transition metal oxides, those graphene materials can provide high pseudocapacitance, hence enhances their energy storage capability.  However, the lower electric and ionic conductivities of transition oxide-based electrodes, hinders the charge transfer and consequently limited their energy storage performance.   In this work, we show that by slight sulfurizing the oxides, we were able to significantly increase the specific capacitance of a graphene-based supercapacitor and achieve of the specific capacitance of ~1100F/g. Such high performance is mainly from the combined effect from improved electric conductivity provided by the nickel structures, along with improved ion diffusion by the porous electrodes structures.  The approach developed in this method provides another venue enhancing the energy storage performance of transition metal oxide-based electrochemical supercapacitors.