Coral-like nanoporous beta-nickel hydroxide nanobars are fabricated by a facile and template-free coprecipitation approach using Na2O2 aqueous as the OH- source. The synthesis process is conducted without agitation at ambient temperature. The structural characteristic and formation mechanism of the corallike beta-Ni(OH)(2) nanomaterials are studied. The as-made beta-Ni(OH)(2) electrode is also characterized by FESEM and XRD. The electrochemical properties of the as-prepared beta-Ni(OH)(2) electrode are examined by cyclic voltammetry (CV), cyclic chronopotentiometry (CP) and electrochemical impedance spectroscopy (EIS) in 6.0 M KOH solution. A specific capacitance of 1780 F g(-1) is obtained at a charge-discharge current density of 1.0 A g(-1). The as-prepared beta-Ni(OH)(2) materials also exhibit excellent rate capability, improved energy density and power density. (C) 2013 Elsevier B.V. All rights reserved.