Hierarchical NiO nanoflowers with porous petals were created by calcining the isomorphological beta-Ni(OH)(2) precursor, which originated from the reaction between Ni(dmg)(2) (nickel dimethylglyoximate) and NaOH. Thus-prepared porous NiO flowers displayed a direct energy band of 3.59 eV and a first discharge capacity of 858 mAh g(-1) vs Li metal. Compared with that of the normal nanoparticles, the higher electrochemical lithium intercalation could be ascribed to their special nanoporous structure. (c) 2007 Elsevier B.V. All rights reserved.