In this work, commercial Ni foams are directly oxidized into Ni@Ni(OH)(2) foams in a mild NH4NO3 solution at 80 degrees C. When used as binder-free electrodes, these Ni@Ni(OH)(2) electrodes demonstrate a high areal capacitance of 6.4 F/cm(2) at a current density of 2.5 mA/cm(2), or 1.62 F/cm(2) at a high current density of mA/cm(2). Nevertheless, they show a poor cycling ability with 70.4% (or 42%) capacitance retention after 2000 (or 5000) cycles at 30 mA/cm(2). This kind of electrodes has a promising application in low-cost, high-performance supercapacitor, if an effective strategy is found to improve their cycling ability. (C) 2016 Elsevier B.V. All rights reserved.