Direct synthesis of graphene-based hybrid films as flexible supercapacitor electrodes

Excellent carbon nanotubes and graphene have attracted more and more attention due to their fascinating properties of combining advantages. In this report, graphene/multi-walled carbon nanotube composite films (G/MWNTs) with excellent mechanical flexibility and high electrical conductivity were prepared by one-step and self-assembly strategy. Importantly, G/MWNTs were equipped with high specific surface areas, which are conductive to growing the micropores and active sites. The electrochemical measurement results indicate that G1/MWNTs exhibit a specific capacitance of 249.3 F g−1 at a current density of 200 mA g−1 and still remain 91.3% of the original specific capacitance after 8000 cycles, indicating an excellent electrochemical performance. Furthermore, the flexible and mechanically stable graphene-based films can be bent to various angles on demand, which is a necessary condition in practical application. The as-prepared G/MWNTs show enormous potential in supercapacitors as high performance electrodes and may be favorable for some other research fields as well.