Magnesium-Ion Cathode Materials based on the Barite Structure

The barite structure (mineral: BaSO4) is a common structure type for alkaline earth metals and is known to exist with many different electrochemically active cations. In this study we have evaluated the electrochemical activity of the barite-type material BaCrO4 as a charged cathode in a standard Mg-ion cell configuration. Electrochemical evaluation of the material, prepared in two different ways, indicated a reversible insertion plateau around 1.0 V (vs Mg/Mg+2) corresponding to the approximate composition Mg-0.1[BaCrO4]. The low inherent electronic conductivity of these insoluble but molecular materials is thought to be the underlying cause of the poor electrochemical performance.