The measurements of charge space capacity versus potential have been carried out on passive nickel electrode. The Mott-Schottky relationship was obtained for different measurement frequencies. The shape of this characteristic depends on selection of the measurement frequency. Due to that fact, the accounted defect concentration depends on frequency also. The Mott-Schottky relationship obtained by means of dynamic electrochemical impedance spectroscopy does not possess this disadvantage. (c) 2005 Elsevier Ltd. All rights reserved.