The Performance of Doped Mesoporous Carbon Electrodes as Electrochemical Capacitors in Optimized Alkaline Electrolyte

Nitrogen and sulfur dual-doped mesoporous carbons were prepared through a facile template-mediated pyrolyzing method using poly(ethyleneimine) (PEI) as sources of nitrogen (N) and carbon (C), ferrous sulfate (FeSO 4 7H 2 O) as both precursor of sulfur (S) and activation reagent along with nanoscaled silica as sacrificial supports. The as-prepared doped mesoporous carbons show perfect supercapacitive performances, which have been demonstrated by cyclic voltammetry and constant-current charge/discharge cycling techniques. The specific capacitance (SC) of the as-prepared electrode can reach 279 F/g at a current density of 1 A/g. Even at a high rate capability of 100 A/g, the electrode still shows the SC value as high as 240 F/g, retaining 86% of that at 1 A/g. Regarding the effect of electrolyte concentrations (1-6M KOH), 3 M KOH gives the best performance. The above results indicate that the doped mesoporous carbon electrodes developed in this work are promising for use in energy storage devices.