Corrosion of magnesium electrolytes: chlorides – the culprit

Abstract

Chloride containing magnesium electrolytes are corrosive towards non noble metals. Currently the development of non-corrosive magnesium electrolytes is a key challenge on the road to a rechargeable magnesium battery. The component responsible for corrosion of magnesium electrolytes has not been previously elucidated. Here we clarify that chlorides in the cation (Mg₂(μ-Cl)₃·6THF)⁺ are a major culprit for corrosion. We also corroborate the feasibility of ion exchange reactions as a suitable synthetic approach towards magnesium electrolytes which do not contain the cation (Mg₂(μ-Cl)₃·6THF)⁺. Our results indicate that magnesium organoborates are an interesting class of magnesium electrolytes which undergo magnesium deposition and dissolution and are non-corrosive in nature at high voltages.