Electrochemically reduced graphene oxide with porous structure as a binder-free electrode for high-rate supercapacitors

Abstract

A binder-free electrode is prepared by directly depositing electrochemically reduced graphene oxide (ERGO) on the metal current collector. Fourier transform infrared spectroscopy and Raman spectrum have been used to demonstrate the effective reduction of graphene oxide on the electrode, and the porous structure of the ERGO film was further characterized by scanning electron microscopy. The electrochemical properties of ERGO were investigated by cyclic voltammetry, galvanostatic charge–discharge and electrochemical impedance spectroscopy (EIS). Electrochemical measurements showed that the binder-free ERGO electrode had high specific capacity, good cycle stability, as well as excellent high-rate capability. The specific capacitance of the constructed electrode was 131.6 F g⁻¹ at a scan rate of 10 mV s⁻¹ and maintained 66.9% of the initial value when the scan rate was increased up to 1000 mV s⁻¹. Owing to its favorable electrochemical performance, this binder-free ERGO electrode with porous structure has great potential in future commercial electrochemical supercapacitors.