Self-assembling graphene-anthraquinone-2-sulphonate supramolecular nanostructures with enhanced energy density for supercapacitors

Boosting the energy density. of capacitive energy storage devices remains a crucial issue for facilitating applications. Herein, we report a graphene-anthraquinone supramolecular nanostructure by self-assembly for supercapacitors. The sulfonated anthraquinone exhibits high water solubility, a pi-conjugated structure and redox active features, which not only serve. as a spacer to interact with. and stabilize graphene but also introduce. extra. pseudocapacitance contributions. The formed. nest-like three-dimensional (3D) nanostructure. with. further hydrothermal treatment enhances the accessibility of ion transfer. and exposes the redox-active quinone groups in the. electrolytes. A fabricated all-solid-state flexible symmetric device delivers a high specific capacitance of 398.5 F g(-1) at 1 A g(-1) ( 1.5 times higher than graphene), superior energy density (52.24 Wh kg(-1) at about. 1 kW kg(-1)) and good stability (82% capacitance retention after 10 000 cycles).