A novel single-step microwave-assisted process has been developed to synthesize spherical beta-Ni(OH)(2) superstructures without using any templates. Structure characterizations show that the spherical beta-Ni(OH)(2) composed of twisted nanosheets was obtained. The electrochemical properties of the as-prepared materials were evaluated by cyclic voltammetry and chronopotentiometry technology in 2 M KOH solution. Due to the unique morphology, the prepared beta-Ni(OH)(2) electrode displays a high specific capacitance of 2147 F g(-1) at a discharge current of 1 A g(-1) and outstanding cycling stability (99.5% capacitance retained after 2000 cycles), suggesting its potential application as an efficient electrode material for high-performance electrochemical capacitors. (C) 2014 Elsevier B.V. All rights reserved.