Electrochemical Deposition and Nucleation of Aluminum on Tungsten in Aluminum Chloride-Sodium Chloride Melts

Abstract

Electrochemical deposition and nucleation of aluminum on tungsten electrode from AlCl3-NaCl melts were studied by cyclic voltammetry, chronopotentiometry and chronoamperometry. Cyclic voltammetry and chronopotentiometry analyses showed that Al (III) was reduced at 200◦C in two consecutive steps in an electrolyte of molten AlCl3-NaCl system with a composition 52:48 molar ratio. The current-time characteristics of nucleation aluminum on tungsten showed a strong dependence on overpotentials. Chronoamperometry showed that the deposition process of aluminum on tungsten was controlled by an instantaneous nucleation with a hemispherical diffusion-controlled growth mechanism. The results could lead to a better understanding of the AlCl3-NaCl melt system that has technological importance in electrodeposition of metals as well as in rechargeable batteries.