Graphene (G) and graphene oxide (GO)/carbon nanotubes (CNTs) hybrid films were fabricated as high performance electrode materials by a simple water solution casting method with different contents of single-wall CNT (SWCNT), multi wall CNT (MWCNT) and multi wall CNT with hydroxyl group (MWCNT-OH). The films with MWCNTs showed a layered, interconnected and well entangled structure at nano-scale. With increasing CNT contents, the capacitance of the G/MWCNT and GO/MWCNT films raised almost linearly and their resistance reduced. G/SWCNT and GO/SWCNT films did not form layered structures leading to a very low capacitance. Nonlinear behaviour of the capacitance with voltage has been observed in the G/MWCNT and GO/MWCNT hybrid films. The dimension of the hybrid film has significant influences on the specific capacitance. The specific capacitance increases with increasing the thickness and decreases with increasing the length of the hybrid films. For the application of graphene/CNT hybrid films as electrodes, these characters must be taken into account.

Graphene (G) and graphene oxide (GO)/carbon nanotubes (CNTs) hybrid films were fabricated as high performance electrode materials by a simple water solution casting method with different contents of single-wall CNT (SWCNT), multi wall CNT (MWCNT) and multi wall CNT with hydroxyl group (MWCNT-OH...