Electrodeposition of Refractory Metals from Ionic Liquids

Abstract

Electrodeopostion of refractory metals from ionic liquids, including tantalum and niobium, has received a great deal of attention due to the potential of these coatings for a wide range of industrial applications. While deposition has been achieved from metal halide salts in both ionic liquids and classic high-temperature molten salt mixtures, these depositions have often resulted in the inclusions of sub-halide species in the coatings. Additionally, for ionic liquids, these processes have typically made use of high cost solvents that are not scalable for industrial applications. To improve the deposition process, we have explored the electrochemical process of producing refractory metal coating from a range of deep eutectic solvents and low cost ionic liquids. In order to understand the fundamental reaction mechanisms that govern the metal reduction and deposition, critical parameters, such as solvent coordination, have been modeled and characterized in solution. Moreover, analytical methods have been used to characterize the reduction process.