Fibrous and flexible supercapacitors with a hierarchical nanostructure comprised of carbon spheres and graphene

A simple electrochemical deposition method is introduced for the preparation of a hierarchical nanostructure comprised of graphene and carbon spheres. The carbon spheres are used as nano-spacers to separate graphene nanosheets, improving properties. This method allowed for the one-step preparation of a fibrous, flexible supercapacitor electrode. The fibrous, flexible supercapacitors fabricated based on this hierarchically nanostructured material achieved excellent electrochemical performance. With an areal capacitance of 60.02mF/cm² (two-electrode system) in aqueous electrolyte, this structure displayed an areal capacitance three times than that of pure-graphene supercapacitors. This method can be employed to fabricate various graphene-based fibrous and flexible composite electrodes for wearable electronics and energy storage applications.