The current response in a chronoamperometric experiment on the alkaline manganese dioxide electrode has been modeled as a composite of two individual discharge processes using a spherical grain diffusion model. This analysis has provided us with the capacity and A root D values for each discharge process, as well as a quantitative means of comparing different EMD samples. This has led to the identification of the domains within the gamma-MnO2 structure in which structural defects such as cation vacancies and Mn(III) ions are most likely to be found. (C) 2008 Elsevier B.V. All rights reserved.