Applications of Ionic Liquids in Electrochemistry

Ionic liquids form a new class of solvents. They are salts melted at temperatures below 100°C. They have many interesting physico-chemical properties, and are used in many cutting-edge fields such as organic synthesis, catalysis, pharmaceuticals, metallurgy and many others. This article deals specifically with applications involving electrochemical techniques and concepts in the broadest sense: corrosion, energy, electrodeposition, electrosynthesis and analytical electrochemistry. The sheer number of applications in these sectors makes it impossible to cover all practical cases exhaustively. Similarly, several thousand ionic liquids have already been the subject of various studies and, theoretically, several million more could be synthesized. For these reasons, we have adopted an approach that consists of reviewing the essential properties of these new reaction media, highlighting the advantages and disadvantages of ionic liquids compared with more common solvents, dealing with examples that show what compromises have to be accepted in order to make the most of particular properties, and finally providing the reader with a bibliography, also not exhaustive, but which will serve as a starting point for delving deeper into one particular aspect or another. Properties examined include electrical conductivity, viscosity, melting, decomposition and glass transition temperatures, electroactivity range, density and surface tension.