In the past years, the nickel-metal hydride rechargeable battery is already been widely used in many application fields, and is now replacing the nickel-cadmium battery. Electrochemical impedance spectroscopy technique is extensively used to reveal the electrode process kinetics, for example, Pb-H2SO4 battery, Ni-Cd battery. There are few reports on the EIS of Ni-MH battery. In this paper, an extensive study is focused on the electrochemical impedance spectroscopy of metal hydride electrode, beta-Ni(OH)(2) electrode and Ni-MH battery with different states of charge. (C) 2003 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.