Kinetics of zinc electrocrystallization correlated with the deposit morphology

Abstract

A model for zinc electrodeposition, with interfacial reactions localized on particular sites of the metal surface, is proposed to account for the electrode kinetics studied by means of c.d. against potential plots and complex impedance measurements.

This mechanism allows one to establish a close correlation between the electrode kinetics and the deposit morphology. On one hand a coupling between the reactions and the surface diffusion of the adions Zn^I_ads is shown to be the origin of the spongy deposits which arise at low c.d. On the other hand a strong acceleration of the nucleation rate, as a result of the autocatalytic formation of the adions, plays an outstanding role in the formation of dendrites triggering at high c.d.