Co(OH)(2) nanoparticles were synthesized using only CoSO4 center dot 7H(2)O and NaOH as reactants without other auxiliary reagents via a simple, low-cost and practical ball-milling technique and investigated as the active electrode materials for supercapacitors. The structure and morphology of the resulting Co(OH)(2) samples were examined by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and transmission electron microscopy (TEM). The observations revealed the formation of brucite-like phase of beta-Co(OH)(2), which had an irregular sphere-like shape with an average size of 50-100 nm. When investigated as electrode materials for supercapacitors, the beta-Co(OH)(2) exhibited good energy-storage performances in terms of high specific capacitance of 599 F g(-1) and excellent capacity retention, suggesting its potential application in the electrode material for supercapacitors. (C) 2011 Elsevier B.V. All rights reserved.