High Energy Density Electrode Materials for Rechargeable Magnesium Batteries

The efficient management of energy sources is critical to addressing future global energy demands.  For example, the growing electrical energy storage needs of mobile and stationary devices demonstrate the need for rechargeable batteries with a variety of application-based performance capabilities, including sufficient energy density, appropriate voltage and current capabilities.  One of the most successful and broadly implemented rechargeable battery technologies developed to date is lithium ion.  However, questions regarding the future of using lithium ion technology for large scale applications center on the sustainability and high cost of lithium, especially due to the projected increase in demand for lithium based electrodes used in hybrid and plug in electric vehicles and stationary (grid) storage.

Of the possible alternatives to lithium ion, rechargeable magnesium-ion batteries are an intriguing candidate, and research into the technology has accelerated in recent years.  Magnesium ion technology is promising due to divalent nature of Mg ions, presenting a potential advantage in terms of high volumetric capacity, the high natural earth abundance of magnesium, and higher atmospheric and thermal stability for magnesium metal relative to lithium metal.  

One critical issue impeding progress in this area has been development of a suitable electrolyte-anode interphase which will enable reversible release of Mg²⁺ ions and reversible charge of Mg based anodes.  A second fundamental challenge is the strong polarization of the small divalent Mg²⁺, requiring mitigation of the inherently slow ion diffusion associated with magnesium-ion cathodes.  Progress toward viable Mg-ion battery systems will be described in this presentation, including recent achievements in the development of anodes, cathodes, and electrolytes.