Nickel(II) ions-intercalated manganese dioxide (Ni/MnO2) film with a layered structure on Pt electrode was subjected to repetitive steps between anodic (+0.8 V) and cathodic (0.0 V) potentials in different conditions. Current response during the repetitive steps varied drastically, depending on the number and duration of steps and the type of electrolyte. This behavior was accompanied by an irreversible morphological transformation of the MnO2 film with retaining the layer structure itself. The potential steps with time durations of 10 and 10 s at +0.8 and 0.0 V, respectively, resulted in thick plates with micrometer-scale consisting of hierarchically clustered MnO2 nanolayers. They were grown vertically to the surface of electrode. The structure thus formed exhibited much improved pseudocapacitive properties, resulting from intercalation/deintercalation of not only monovalent cations but also divalent cations. That is, the film had specific capacitances of 225 and 318 F g(-1) at a scan rate of 2 mV s(-1) in Na+- and Ca2+-containing electrolytes, respectively. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.069204jes] All rights reserved.