A novel electrode material for supercapacitor composed of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT) and graphitic-phase C3N4 (g-C3N4) was prepared by a layer-by-layer assembly method. The resulting composite of PEDOT/g-C3N4 represented excellent electrochemical stability in neutral electrolyte and enhanced electrochemical performance of capacitance and average energy density in comparison with single PEDOT. The specific capacitance was 137 F g(-1) in H2SO4 and 200 F g(-1) in Na2SO4 at a current density of 2 A g(-1), respectively. More significantly, the average energy density was 9.65 W h kg(-1) at an average power density of 4001.86 W kg(-1) in H2SO4. While in Na2SO4, the average energy density reached 17.5 W h kg(-1) at an average power density of 5000W kg(-1). More than 89% and 96.5% of capacitance were retained in H2SO4 and Na2SO4 respectively, suggesting that PEDOT/g-C3N4 possessed an excellent cycling stability in view of capacity performance as electrode materials. The property improvement was attributed to the synergistic effects of the two components in the composite. (C) 2015 Elsevier B.V. All rights reserved.