The nitrogen and oxygen co-doped hollow carbon spheres（HCSs） were prepared via a simple pyrolysis of solid melamine-formaldhyde resin spheres. The carbonization temperature has an important influence on the specific surface area, pore-size distribution and heteroatom contents of HCSs. The synergistic effects of those physical and chemical properties on supercapacitor performance were systematically investigated. Among the HCSs obtained at different temperatures, HCSs-800（co-doped HCSs at 800℃） exhibits the best reversible specific capacitance in 2 mol/L H2SO4 electrolyte and meanwhile maintains a high-class capacitance retention capability. The nitrogen heteroatoms were confirmed to play a crucial role in improving capacitance in an acid medium. This kind of nitrogen doved HCSs is a potential candidate for an efficient electrode material for supercapacitors.
MA Fang-weiSUN Li-pingZHAO HuiLI QiangHUO Li-huaXIA TianGAO Shan
