Polyaniline (PANI) nanoparticles have been prepared by disperse polymerization of aniline in the presence of poly(4-styrenesulfonate). The PANI nanoparticles are further subjected to pyrolysis treatment and chemical-activation to prepare the activated nitrogen-doped carbon nanoparticles (APCNs). The porosity, structure and nitrogen-doped surface chemistry are analyzed by a varies of means, such as scanning electron microscopy, transition electron microscopy, N-2 sorption, X-ray diffraction and X-ray photoelectron spectroscopy. The capacitive performance of the APCNs materials are test in 6 M KOH electrolyte. Benefitting from the abundant micropores with short length, large specific surface area, hierarchical porosity and heteroatom-doped polar pore surface, the APCNs materials exhibit v exhibit very high specific capacitance up to 341 F g (1), remarkable power capability and excellent long-term cyclic stability (96.6% after 10 000 cycles). At 40 A g (1), APCN-2 carbon shows a capacitance of 164 F g (1), responding to a high energy and power densities of 5.7 Wh kg (1) and 10 000Wkg (1). (C) 2015 Elsevier Ltd. All rights reserved.