Electrochemistry in Molten Oxides: From Electrolyte Design to Oxygen Evolution

The future carbon-free electricity offers substantial promises for electrochemical engineering, in particular its application to materials processing. As a matter of fact, electricity and electrochemical phenomenon have already significantly contributed to modern metal extraction and manufacturing [1]. More developments are however needed to pursue such trends, in particular for the extraction of metals with limited environmental impact. In that respect, molten oxides electrolytes have a particular appeal identified more than a century ago [2], thanks to their remarkable chemical stability at a temperature range that allows the production of liquid metal. This presentation offers first to review the intrinsic performances of molten oxides as electrolytic medium, and their corresponding key physicochemical properties. In a second time, the most recent discoveries related to the oxygen evolution reaction in such electrolyte will be presented, in particular with respect to mass transfer limitations [3] and anode materials design [4].

[1] A. Allanore, Journal of Metals - JOM, vol. 65, issue 2, 131, (2013)

[2] R. H. Aiken, Process of making iron from the ore. US patent 816, 142 (1906)

[3] A. Allanore, Electrochimica Acta, 110, 587-592, (2013)

[4] A. Allanore, L. Yin and D.R. Sadoway, Nature, 497 (7449), 353–356, (2013)