Electrodeposition Of Magnesium In Ionic Liquids

Ionic liquids which are liquids at ambient temperature, are composed of organic cation and organic or inorganic anions. They have wide electrochemical windows, so many active metals can be electrodeposited from ionic liquids. Compared with conventional electrodeposition process, the magnesium electrodeposition in ionic liquids can reduce energy consumption and pollution.The solubility and dehydration of MgCl₂·6H₂O in various ionic liquids were investigated. The results showed that MgCl₂·6H₂O and MgCl₂ are soluble (20%⁷0%) in hydrophilic ionic liquids, especially those with chloride anion. The moisture content after dehydration was lower than 100ppm which satisfies the request of electrodeposition.The electrodeposition of magnesium from various MgCl₂-ILs systems was further studied. The cathodic limit of ionic liquids (including alkylimidazolium, trialkylimidazolium and quaternary ammonium ILs), the reduction potential of magnesium and deposition process were studied using cyclic voltammetry, scanning electron microscope(SEM) and energy dispersive spectrometer(EDS). It was showed that magnesium can be deposited from MgCl₂-ILs systems, but the reduction potential of magnesium is not more negative than that for the reduction of ionic liquids cation and reversibility of magnesium is not very well.