Electrochemical Properties of Flexible Reduced Graphene Oxide (rGO)/Single-walled Carbon Nanotubes (SWCNTs) Composite Electrode for Energy Storage Device

Acid-treated single-walled carbon nanotubes (ASWNTs) were obtained from single-walled carbon nanotubes functionalized by nitric acid. The flexible electrodes based on reduced graphene oxide (rGO) and ASWCNTs were fabricated via spray coating technique. The electrochemical properties of the flexible electrodes were evaluated using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge/discharge (GCD) measurements in the aqueous electrolyte of 1 M H2SO4. The flexible rGO/ASWCNTs (optimal weight ratio between rGO and SWCNTs= 1: 9) electrode exhibited the highest electrochemical performance. The specific capacitance value of the unbent flexible rGO/SWCNTs electrode was 115 F g (-1), which decreased to 112 F g (-1) (97% retention) after 1000 GCD cycles. The initial capacitance value (115 F g (-1)) decreased to 107 F g (-1) (93% retention) after 500 bending with application of 6000 GCD cycles.