A novel CuO electrode material with flower-like nanostructures was fabricated at a low temperature (80 degrees C) by a simple chemical precipitation method. Scanning electron microscopy (SEM) results showed that CuO with spherical and flower-like structure can be formed under a weak alkali (C(6)H(12)N(4)), and CuO with sheets structure can be obtained under a strong alkali (NaOH). A possible growth mechanism of CuO nanocrystals was discussed. The flower-like CuO electrode exhibited a higher specific capacitance (133.6 Fg(-1)) and an excellent cycle performance at a high current density of 10 mA/cm(2). Specific capacitance of flower-like CuO was 405.3% higher than globular CuO (26.44 Fg(-1)) at 2 mA/cm(2). (c) 2008 Elsevier Ltd. All rights reserved.