(385e) Metal Dissolution in Molten Salts for Redox Control

Molten chloride salts have great potential for higher efficiency heat transfer compared to nitrate-based salts. The chloride-based salts can operate at higher temperatures and in turn produce more electricity. The redox potential of the chloride salts is much greater at higher temperatures and can easily corrode common alloys. In this study, the electrochemical effect of adding magnesium metal to a MgCl2-KCl-NaCl salt mixture was investigated. The solubility of the magnesium in the MgCl2-KCl-NaCl salt mixture was analyzed at different temperatures to determine the maximum saturation point. Through open circuit potentiometry it can be seen that the redox potential of the salt decreased when magnesium was added. Cyclic voltammetry shows both a reduction and oxidation peak, with the reduction peak being greater in size. These results signify that the addition magnesium metal could be an advantageous medium to control redox potential in the MgCl2-KCl-NaCl salt.