Graphene/carbon nanotube films prepared by solution casting for electrochemical energy storage

Graphene oxide/carbon nanotube (GO/CNT) films with different CNT contents were prepared by a solution-casting method. The oxygen-containing groups on the GO/CNT films were removed by thermal annealing at 200°C and the corresponding hybrid graphene/CNT films were obtained. The graphene/CNT films have good mechanical and electrical properties as well as high stability in electrolyte due to the combination of the film-formation capability of graphenes and the excellent mechanical and electrical properties of CNTs. These graphene/CNT films could be directly used as a supercapacitor electrode without assistance of any binders and metal current collectors, demonstrating good electrochemical capacitance performance with the specific capacitance of 70-110 F/g at a low scan rate of 1 mV/s.