Conductive behaviour and self-conductance characteristic of carbon nanotubes/functionalized graphene hybrid films

Multi-walled carbon nanotubes (MWCNTs)/Functionalized graphite (FG) hybrid films were fabricated by a simple solution-casting method. The films showed a layered, well-entangled and interconnected porous structure at nanometer scale. Such the nanostructures resulted in the films having the relatively high bulk conductivity and self-conductance characteristics. With increasing MWCNT mass fraction, the conductivity rapidly increased from approximately 10(-9) S/m of the host FG to over 10(-1) S/m. The percolation threshold was found to be about 29.6 wt% of MWCNTs. For the film with 83 wt% MWCNTs the specific capacitance was about 1 F/cm3. The hybrid films are of much higher power factor compared to conventional dielectric capacitors. The energy density of the film with 50 wt% MWCNTs was found to be 0.1 Wh/m3 and the charge-discharge period was very short about 8 seconds. It is believed that the MWCNTs/FG hybrid films have great potential as electrode materials for applications to energy storage.