High-performance supercapacitors based on reduced graphene oxide -wrapped carbon nanoflower with efficient transport pathway of electrons and electrolyte ions

Despite that a variety of carbon materials have been explored for electrochemical energy storage, rationally design the carbon structure for efficient electrons transfer and ions diffusion to further improve its performance is still a challenge. In this report, a novel three-dimension hybrid carbon material (NCNF/RGO) prepared from reduced graphene oxide (RGO) and N-doped carbon nanoflower (NCNF) consisting of carbon nanosheets has been fabricated by a hydrothermal treatment and freeze-drying method, and demonstrated as supercapacitor's electrode. Benefiting from such structure design with thin porous nanosheets, interworking mesoporous channel and RGO wrapping for efficient electrolyte ions diffusion and electrons transfer, the resulting hybrid electrode displays high specific capacitance of 344 F g−1 at a current density of 0.5 A g−1 and 179 F g−1 even at 50 A g−1 in the KOH electrolyte, and 152 F g−1 at 1 A g−1 in the ionic liquid electrolyte with a wide voltage range. Significantly, the assembled symmetric supercapacitor using the NCNF/RGO as electrode materials reaches a large energy density of 84.2 Wh Kg−1 at a power density of 1.0 kW kg−1, indicating its great potential application.