Influence of the complex formation on the morphology of lead powder particles produced by the electrodeposition processes

Abstract

The processes of lead electrodeposition from the basic (nitrate) and complex (acetate) electrolytes were mutually compared by the analysis of their polarization characteristics and by the scanning electron microscopic (SEM) analysis of the morphology of formed deposits. Although the polarization characteristics of lead recorded from these two electrolytes were relatively similar to each other, the shape of formed dendrites strongly depended on the type of electrolyte. The dendrites composed of stalk and weak developed primary branches (the primary (P) type) were predominantly formed from the basic electrolyte. On the other hand, the very branchy dendrites composed of stalk and of both primary and secondary branches (the secondary (S) type) were mainly electrodeposited from the complex electrolyte. Considering the fact that the application of lead powder in many technologies is closely related with its surface morphology, the special attention was given to the analysis of the type of electrolytes on formation of the different dendritic forms. It was shown that formation of more branchy dendrites from the acetate electrolyte can be ascribed to the lower exchange current density (or to the lower rate of electrochemical process) for this electrolyte than for the nitrate one due to the process of complex formation.