Magnesium batteries are a compelling alternative to lithium-ion batteries on the basis of safety, resource abundance, and energy density. Yet until recently magnesium battery research received little attention, and progress remains slow. The two main hurdles have been the poor performance of positive electrode materials and the dearth of magnesium electrolytes with which to study them.

This is attributable to the much more complicated electrochemistry of magnesium relative to well-established lithium-ion battery studies. Well documented examples include the passivation of magnesium metal[1], corrosion of current collectors[2], and low voltage stability of magnesium electrolytes[3]. Nevertheless, a critical look at the literature reveals that many magnesium studies are conducted using experimental designs that are either dubious or unlikely to yield encouraging results[4].

To address these discrepancies, we show that appropriate electrochemical design choices are crucial to the success of magnesium experiments. This study analyzes how different electrolytes, current collectors, and electrode materials work with (or against) each other. This work is intended to provide a platform for the search for high energy magnesium battery electrode materials.

References

[1] Z. Lu, A. Schechter, M. Moshkovich, D. Aurbach, On the electrochemical behavior of magnesium electrodes in polar aprotic electrolyte solutions, J. Electroanal. Chem. 466 (1999) 203–217. doi:10.1016/S0022-0728(99)00146-1.

[2] D. Lv, T. Xu, P. Saha, M.K. Datta, M.L. Gordin, A. Manivannan, et al., A Scientific Study of Current Collectors for Mg Batteries in Mg(AlCl2EtBu)2/THF Electrolyte, J. Electrochem. Soc. 160 (2012) A351–A355. doi:10.1149/2.085302jes.

[3] J. Muldoon, C.B. Bucur, A.G. Oliver, J. Zajicek, G.D. Allred, W.C. Boggess, Corrosion of magnesium electrolytes: chlorides – the culprit, Energy Environ. Sci. 6 (2013) 482. doi:10.1039/c2ee23686a.

[4] R.C. Massé, E. Uchaker, G. Cao, Beyond Li-ion: electrode materials for sodium- and magnesium-ion batteries, Sci. China Mater. 58 (2015) 715–766. doi:10.1007/s40843-015-0084-8.