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

摘要

Electrochemical deposition and nucleation of aluminum on tungsten electrode from AlCl_3-NaCl melts were studied by cyclic voltammetry,chronopotentiometry and chronoamperometry.Cyclic voltammetry and chronopo- tentiometry analyses showed that Al(Ⅲ) was reduced at 200℃in two consecutive steps in an electrolyte of molten AlCl_3-NaCl system with a composition 52:48 molar ratio.The current-time characteristics of nucle- ation 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 AlCl_3-NaCl melt system that has technological importance in electrodeposition of metals as well as in rechargeable batteries.