Solid state reactions: an electrochemical approach in molten salts

Solid state reactions play crucial roles in highly efficient electrochemical energy conversion and storage devices, typically lithium ion batteries and ruthenium oxide supercapacitors. Electrolytic processes may also involve solid-to-solid changes such as the anodisation of metals for designated surface nanostructures and functionalities. More recently, a novel and green route for the production of metals and alloys in molten salts has drawn worldwide attention. It is based on the electro-reduction of metal compounds, particularly oxides, to the respective metals or alloys in the solid-state. This article reviews recent advancement of this new process in terms of potential applications and fundamental understanding.