Fabrication of flexible free-standing reduced graphene oxide/polyaniline nanocomposite film for all-solid-state flexible supercapacitor

Graphene and polyaniline (PANI) are considered as promising electrode active materials. A rational design of composite structure for graphene and PANI is essential and prerequisite for obtaining excellent properties. In this paper, a flexible free-standing reduced graphene oxide (rGO)/PANI nanocomposite film has been successfully prepared through self-assembly and in situ polymerization of anilines in graphene oxide (GO) sheets. Owing to the formation of PANI nanoparticles, the electrochemical capacitance of rGO/PANI nanocomposite film is significantly enhanced. To evaluate electrochemical properties, an all-solid-state flexible supercapacitor is further fabricated through tailoring and assembling the flexible free-standing rGO/PANI nanocomposite film. The nanocomposite film shows high specific capacitance of 0.92 F/cm2 (>1314.3 F/cm3) and its specific capacitance exhibits no obvious fading under bending state or after bending 200 times. The excellent electrochemical performance can be readily ascribed to the synergistic effect between two-dimensional rGO and PANI nanoparticle in the nanocomposite film. This study demonstrates an efficient approach to prepare flexible free-standing active materials for flexible energy storage devices.