The Effect of Electrolyte Flow on the Morphology of Zinc Electrodeposited from Aqueous Alkaline Solution Containing Zincate Ions

Abstract

The effect of flowing electrolyte on the morphology of zinc electrode‐posited from aqueous alkaline solution has been investigated. Aqueous potassium hydroxide solution of 5.8N normality containing 19.1 g/dm³ of dissolved zinc oxide was circulated through a flow tube at flow velocities up to 1.7 m/s, corresponding to Reynold's numbers of up to 13,500. The morphologies of zinc electrodeposits formed on a zinc substrate in the wall of the flow tube were examined over a range of current densities and Reynold's numbers. The results showed that flowing electrolyte under both turbulent flow and laminar flow conditions greatly modified the deposit morphologies. It was possible to construct a morphology, current density, and Reynold's number “phase diagram” to describe the effects of flowing electrolyte on deposit morphology.