Effects of Cuprous Ion on Electrodeposition of Aluminum from AlCl 3 -BMIC Ionic Liquid

The effect of Cu(I) ions on electrodeposition of aluminum from AlCl 3 -BMIC (AlCl 3 -1-butyl-3-methylimidazolium chloride) ionic liquid was investigated. The cyclic voltammetry and cathodic polarization analyses showed that Cu(I) ions obviously decreased the nucleation overpotential of Al and promoted the reduction reaction of Al (III). The analysis of thechronoamperometric transients indicated that the presence of Cu(I) does not change the nucleation and growth mode of Al deposition, but affects nucleation rate. Besides, the addition of Cu(I) slightly decreased the cathodic current efficiency (CE), increased the power consumption (PC), and reduced the purity of Al deposit. X-ray diffractogram revealed the presence of Cu(I) ions in electrolyte affected the preferred orientations of the electrodeposited Al by promoting the growth of (220) plane. SEM images showed that the grain of the Al deposit was refined with the increase of Cu(I) ions.