AZ31 Magnesium Alloy foils as thin Anodes for Rechargeable Magnesium Batteries.

In recent decades rechargeable Mg batteries (RMB) technologies have attracted much attention because the use of thin Mg foils anodes may enable to develop high energy density batteries.  One of the most critical challenges for devolving  RMB is finding  suitable  electrolyte solutions that enable efficient and reversible Mg cells operation. Most RMB studies concentrate on the development of novel electrolyte systems, while only few studies have focused on the practical feasibility of using pure metallic Mg as the anode material. Pure Mg metal anodes have been demonstrated to be useful in studying the fundamentals of nonaqueous Mg electrochemistry. However, pure Mg metal may not be suitable for mass production of ultrathin foils (< 100 microns) due to its limited ductility. The metals industry overcomes this problem by using ductile Mg alloys. We demonstrate herein the feasibility of processing ultrathin Mg anodes in electrochemical cells by using AZ31 Mg alloys (3% Al; 1% Zn). Thin film Mg AZ31 anodes present reversible Mg dissolution and deposition behavior in complex ethereal Mg electrolytes solutions that is comparable to that of pure Mg foils. Moreover, we demonstrated that secondary Mg battery prototypes comprising ultrathin AZ31 Mg alloy  anodes (≈ 25 µm thick) and Mg x Mo 6 S 8 Chevrel phase cathodes exhibit cycling performance that is equal to that of similar cells containing thicker pure Mg foil anodes. The possibility of using of ultrathin processable Mg metal anodes is an important step in the realization of rechargeable Mg batteries.