The effect of interfacial deformation on electrodeposition kinetics

Mullins-Sekerka linear stability analysis and the Barton and Bockris dendrite-propagation model are popular methods used to describe cathodic roughening and dendritic growth. These commonly cited theories employ kinetic relationships that differ in mathematical form, but both contain the effects of surface tension and local concentration deviations induced by surface roughening. Here, a kinetic model is developed which additionally includes mechanical forces such as elasticity, viscous drag, and pressure, showing their effect on exchange current densities and potentials at roughening interfaces. The proposed expression describes the current density in terms of applied overpotential at deformed interfaces with arbitrary three-dimensional interfacial geometry. Both the Mullins-Sekerka and the Barton-Bockris kinetics can be derived as special cases of the general expression, thereby validating the proposed model and elucidating the fundamental assumptions on which the two previous theories rely. (C) 2004 The Electrochemical Society.