The influence of the deposition of a coating material on the electrode surface in an electrochemical cell on the current-voltage characteristics is investigated. The surface covering of particles is evaluated from the surface current density of the ions. The current-voltage characteristics for the cases when the surface deposition increases or reduces the surface resistance of the electrode are derived. The differential conductance, defined as the derivative of the current with respect to the applied voltage, is evaluated. The cases of small and large overpotential are considered. An extension of the model to a real situation in which the external potential applied to the cell is a step of a given amplitude is also considered. (C) 2015 Elsevier B.V. All rights reserved.