Application of ionic liquids to the electrodeposition of metals

TLDR

Electrodeposition of technologically important metals from room‑temperature ionic liquids has been demonstrated, yet industrial‑scale processes remain undeveloped despite intense scrutiny of these molten salts. This review examines the practical and theoretical considerations for selecting ionic liquids for metal deposition and outlines the knowledge gaps that must be addressed to develop viable electroplating systems. It discusses how composition and temperature influence viscosity and conductivity and describes the fundamental strategies for synthesizing new ionic liquids.

Abstract

The electrodeposition of most of technologically important metals has been shown to be possible from a wide range of room temperature molten salts, more commonly known today as ‘ionic liquids’. These liquids are currently under intense scrutiny for a wide variety of applications some of which have already been commercialized. Despite the fact that electrodeposition was the first application studied in these liquids no metal deposition processes have as yet been developed to an industrial scale. This review addresses the practical and theoretical aspects that need to be considered when choosing ionic liquids for metal deposition. It details the current understanding of the physical and chemical properties of these interesting fluids and highlights the areas that need to be considered to develop practical electroplating systems. The effect of composition and temperature on viscosity and conductivity are discussed together with the fundamental approaches required to synthesise new liquids.