The Mechanism of the Dendritic Electrocrystallization of Zinc

Measurements have been made of the growth rate of zinc dendrites in alkaline zincate solutions as a function of overpotential (η), concentration , and temperature . The tip radii have been measured by electron microscopy. At constant potential, an initiation time of between 5 and 100 min is observed, depending on η, c, and T. The dendrite grows linearly with time, at a rate depending on η, c, and T. The total current to base and dendrite was independent of time until a time , where (the time for initiation obtained from the growth rate vs. time relation). Thereafter, . A critical overpotential was determined, . Below this , sponge was formed. Dendrites were observed up to ; above this the deposition was heavy sponge. At a given , the growth rate of a given dendrite increased with η according to an exponential law. The growing tip is parabolic, where . No twinning was observed.