Morphology and structure control of amine- functionalized graphene/polyaniline composite for high-performance supercapacitors

Over the past few years, supercapacitors based on graphene/polyaniline (rGO/PANI) composites have gained immense attention. The electrochemical performance of rGO/PANI composites can be improved by controlling their morphology and structure. However, very few studies have been carried out on amine-functionalized graphene/polyaniline (F-rGO/PANI) composites. In this study, amine-functionalized graphene (F-rGO) and mesoporous graphene (PF-rGO) were composited with PANI. The results showed that the specific capacitance of the F-rGO/PANI composites could be improved by controlling their morphology. The mesoporous structure of F-rGO contributed to the improvement in the cycling stability and energy density of the composites. At a current density of 0.5 A g−1, the specific capacitances of F-rGO/PANI20–0.5h and PF-rGO/PANI are 597 F g−1 and 489 F g−1, respectively; these values are remarkably higher than that of pure PANI (400 F g−1). F-rGO/PANI20-0.5th and PF-rGO/PANI maintained specific capacitances of 75% and 89%, respectively, which were significantly higher than that of pure PANI; this was observed even after 2000 cycles of charge and discharge had been completed at a current density of 1 A g−1. The energy density of PF-rGO/PANI reaches 34.9 W h kg−1 at the power density of 1.27 kW kg−1. This study is expected to provide an effective basis for the future research of graphene-based composite electrode materials for supercapacitors. •Amine-functionalized graphene (F-rGO) was synthesized.•The morphology of F-rGO/PANI composite was controlled.•Morphology control delivers excellent energy storage capability.•The cycling stability of mesoporous F-rGO/PANI significantly improved.•Controllable morphology coupled with mesoporous structure are beneficial for energy storage.