Critical Overpotential and Induction Time of Dendritic Growth

Relationships developed earlier (1) for the dependence of the rate of appearance and propagation of dendrites on the properties of the system and overpotential, have been used to develop a quantitative theory of induction period and critical overpotential of dendritic growth. It has been shown that the thermodynamic concept of critical overpotential is applicable to metals of high exchange current density only. The limitations in the appearance of dendrites in metals of low exchange current density are of kinetic character and can be represented by a kinetically defined critical overpotential. The theory has been verified experimentally by following the yield of dendritic deposit of zinc from alkaline zincate solutions as a function of concentration of depositing ions, of overpotential, and of time of deposition.