Nanocrystalline intermetallic Mo2C has been synthesized via carbonizing of molybdenum oxides and studied as a capacitive material for electrochemical energy storage. A specific capacitance of 218 F g(-1) is found in aqueous 1 mol dm(-3) H2SO4 at 20 degrees C using a specific current density of 1 A g(-1), with 5.3% loss of capacitance being experienced after 10000 cycles of charging-discharging. 88.5% of the initial value remains at a specific current density of 10 A g(-1). Electrochemical capacitance of Mo2C may be attributed to its electrical conductivity and nanostructure that can promote the electrochemical performance observably and ensure a long cycle life and electrical charge transfer. The assembled asymmetrical Mo2C//AC electrochemical capacitor shows an energy and power density of 23.5 W h kg(-1) and 9028.8 W kg(-1), facilitating duty applications. (C) 2016 The Electrochemical Society. All rights reserved.