High-efficiency supercapacitors based on V2O5/rGONR network from hierarchical nanoribbon assemblies

Nanostructured transitional metal oxides integrating with carbon-based materials have been extensively applied in energy storage owing to their high specific capacitance. However, it remains a great challenge to keep high active surface area and prevent from stacking or agglomeration for advanced performance. Herein we report a hierarchical design for high-efficiency supercapacitor with meso-holes in graphene nanoribbons, intertwined network of vanadium pentoxide (V2O5) nanoribbons and holey graphene nanoribbons (rGONR), and 3D interconnected macroporous structure. Such architecture effectively prevents the stacking or agglomeration of both nanoribbons due to their similar size and fast assembly time. The binary network exhibits high specific capacitance up to 712 F/g (@1 A/g) and good cycle performance mainly owing to the hierarchical porous structure which can facilitate the diffusion of electrolyte ions, rich active surface area of V2O5 nanoribbons for redox reactions and pseudocapacitance from the edge planes of holey graphene nanoribbons.