Developing Synthetic Routes to Magnesium Battery Cathodes

Tuesday, 3 October 2017: 10:40
Maryland A (Gaylord National Resort and Convention Center)
A. Wustrow, J. T. Incorvati, J. Hancock (Northwestern University), J. T. Vaughey (JCESR at Argonne National Laboratory), and K. Poeppelmeier (Northwestern University)
Magnesium batteries are one of the most promising topics for next generation energy storage chemistries owing to their high theoretical energy density and similarities in testing and evaluation to more commonly studied lithium-ion systems. However they remain a relatively underexplored area due to limitations in our understanding of the storage mechanism among available electrolytes and cathode materials. While magnesium cations have been shown to reversibly intercalate into many known materials, for example Mo6S8, V2O5 and Ti2S4, expanding this work has proved difficult owning to the lack of suitable analogous structures for further study. We recently have made several advances in developing an understanding of the role of oxide lattice stability and intrinsic conductivity in creating a new generation of higher voltage cathode materials when we reported on the layered molybdenum oxide fluorobronze Mgx[MoO2.8F0.2]. In this example by developing active materials with stronger metal oxide bonds, the storage mechanism shifted from irreversible MgO formation by oxide abstraction (seen in MnO2) to true reversible intercalation. Electrochemical experiments were made possible by a new lower temperature, phase pure synthetic route which allowed us to easily scale the reaction. This talk will focus on the importance of synthetic chemistry to the advancement of the field and highlight new routes designed to expand the number of active cathode materials designed for multivalent cations.