The present paper reports a new catalytic electrolysis method to prepare NiOOH. KMnO(4) is proposed as a catalyst to play the role of electron-transfer medium in the electrolysis preparation of NiOOH for the first time. Through the self-redox reaction of KMnO(4), the highly efficient electron-transfer process between the electrolyte and the electrode of the spherical Ni(OH)(2) is realized, thus resulting in a high electrolytic efficiency and short electrolysis time. The mechanism of catalytic electrolysis is preliminarily discussed. The experimental results show that the electrode prepared with the NiOOH powders by catalytic electrolysis offers a discharge capacity of 267 mAh g(-1) at a current density of 120 mA g(-1) and exhibits good cycling performance. (C) 2008 Elsevier Ltd. All rights reserved.