Surface Modification of Sputtered Carbon Supercapacitor Electrode by Hydrogen Annealing

Abstract

In the applications of renewable energy; use of energy in the electric vehicles and many other electronic devices such as mobile devices and computers; electrical energy storage is essential. Batteries are used to store electrical energy but have low power density and lower cycle life. Using extremely porous electrode materials for supercapacitors, based on quick ion transport, are specialized to provide high power density, long stability and effective energy storage. Using graphene-based electrode is the best way to boost the energy density of supercapacitor. Graphene synthesized by chemical exfoliation, ultrasonic exfoliation and solution based chemical reduction suffers agglomerations that tends to restack the graphene sheets. In the present work, we studied the option of hydrogen gas annealing to obtain graphene from amorphous carbon film, coated on Cu substrate using sputtering. For electrochemical assessment, in situ developed film was compared with graphene applied from other methods of graphene synthesis. Atomic force microscopy (AFM) results revealed that annealed carbon sputtered electrode has high route mean square (RMS) roughness i.e 181.5 nm, most probably because of graphene formation. Cyclic voltammogram (CV) results show less area curve for annealed electrode which depicts high active area for charge storage and enhanced conductivity due to deposited graphene layer.