Carbon aerogel (CA) was prepared by a sol-gel polymerization of resorcinol and formaldehyde, and a series of activated carbon aerogels (ACA-X, X H3PO4, K2CO3, KOH, and ZnCl2) were then prepared by a chemical activation using different activation agent (X represented an activation agent). Specific capacitances of activated carbon aerogels were measured by cyclic voltammetry and galvanostatic charge/discharge methods in 6 M KOH electrolyte. Among the samples prepared, ACA-K2CO3 showed the highest specific capacitance (152 F/g). In order to combine excellent electrochemical performance of activated carbon aerogel with pseudo-capacitive property of manganese oxide, 7 wt% manganese oxide was doped on activated carbon aerogels (Mn/ACA-X) by an incipient wetness impregnation method. Capacitance measurements revealed that Mn/ACA-K2CO3 showed the highest specific capacitance (189 F/g). The enhanced capacitance of Mn/ACA-K2CO3 was attributed to the fine pore structure and outstanding electric properties of activated carbon aerogel as well as the faradaic redox reactions of manganese oxide. (C) 2012 Elsevier B. V. All rights reserved.