Electrochemical synthesis of highly corrugated graphene sheets for high performance supercapacitors

Abstract

Highly corrugated graphene sheets with low susceptibility to re-stacking were prepared by electrochemical reduction of graphene oxide (GO) in a molten salt bath. Oxygen functional groups were removed by depositing the reducing agent on a GO assembled cathode and also by direct electro-deoxygenation without generating reducing agents. The produced graphene derivative had electrical conductivity as high as 2300 S m⁻¹, and a specific surface area of 565 m² g⁻¹ making it ideal as a supercapacitor with maximum specific capacitance of 255 F g⁻¹ in 6 M KOH aqueous solution without the need for doping the graphene sheets. Further, the supercapacitor showed excellent cycling stability, retaining 95% of its initial capacitance after 5000 cycles of charge/discharge. Therefore, this material presents great promise for future design and large-scale production of affordable and high performance graphene electrodes for portable energy storage devices.