Co2MnO4/Co hydroxide chloride (CMO/CHC) nanocomposite is firstly obtained through an electrochemically alternating voltage methodology for supercapacitor applications. The CMO/CHC electrode materials display a high specific capacitance of 779 F g(-1) at 1 A g(-1) and an excellent rate behavior (77.5% and 63.6% at 20 and 40 A g(-1) compared with 1 A g(-1), respectively). An asymmetric supercapacitor based on CMO/CHC as cathode and activated carbon (AC) as anode presents a maximum energy density of 27.8 Wh kg(-1) at power density of 570.9 W kg(-1). (C) 2015 Elsevier Ltd. All rights reserved.