Electrodeposition of Aluminum from AlCl3-1-Ethyl-3-Methylimidazolium Fluoride

Abstract

The electrodeposition of aluminum was successfully achieved in AlCl3-1-ethyl-3-methylimidazolium fluoride (EmimF) at a potential of -0.3V (vs. Al/Al3+) and a temperature of 90 °. Cyclic voltammetry, chronopotentiometry and chronoamperometry were used to investigate the electrochemical behavior of Al2Cl7-. Cyclic voltammetry and chronopotentiometry measurements indicate that the reduction of Al2Cl7- to metallic Al in AlCl3-EmimF (molar ratio 2.7) is a one-step three-electron transfer and irreversible diffusion-controlled process. The chronoamperometry results show that the deposition of aluminum on a Pt electrode involves instantaneous three-dimension nucleation. In addition, X-ray diffraction (XRD) analysis confirmed that the deposit is pure aluminum, while scanning electron microscope (SEM) images reveal that dense and compact deposits were obtained at a more negative potential.