▎ 摘　　要

A series of poly(sodium-4-styrene sulfonate) functionalized graphene/manganese dioxide (PSS-GS/MnO2) composites as electrode materials for supercapacitors are prepared via a simple and facile route. The morphology and microstructure of the as-prepared samples are characterized by field-emission scanning electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, Raman microscope and X-ray photoelectron spectroscopy. The electrochemical performances of the as-prepared composites are evaluated by cyclic voltammetry, galvanostatic charge/discharge experiments and electrochemical impedance spectroscopy in 1 M Na2SO4 electrolyte, demonstrating that the resulting composite materials exhibit excellent gravimetric capacitance and long cycle life. Moreover, the relationship of the specific surface areas and electrochemical performance is investigated and discussed. The results demonstrate that the specific capacitance increases with the increase of the specific surface area and the specific capacitance of PSS-GS/MnO2-2 with the highest specific surface area can reach 223 F g(-1) at the current density of 0.1 A g(-1). The enhanced specific capacitance can be attributed to the higher specific surface area and uniform pore size distribution, which enable effective electrolyte transport and active site accessibility.