Electrodeposition of indium and tin from molten chloride electrolytes

Abstract

Recycling of electronic waste to recover the metal value is of prime importance, especially for metals with limited resources. An electrochemical approach should be an interesting option to develop sustainable recycling processes. The electrochemical deposition of tin was studied by cyclic voltammetry at glassy carbon electrodes in molten LiCl-KCl at 450 °C. Tin deposition on glassy carbon was found to be diffusion controlled in molten LiCl-KCl containing 0.1 mol% SnCl2. At higher anodic voltage, Sn2+ was oxidised to Sn4+. The cathodic discharge of indium ions to form metallic indium was shown to take place by a consecutive two-step electrochemical process involving In3+, In+ and metallic indium. The direct deoxidation of solid ITO was studied by using different electrodes such as Mo wire and liquid Zn. An ITO covered glass electrode was investigated by electrochemical means in molten LiCl-KCl at 450 °C using a Mo wire current lead.