Electrochemical Properties of Magnesium Electrodes in Lithium Non-Aqueous Electrolytes. Perspective of High-Energy Hybrid Magnesium Batteries

Abstract

Magnesium is a promising alternative to the lithium as a negative electrode in primary and rechargeable power sources with non-aqueous electrolytes. Magnesium comparative to Lithium has a higher specific discharge capacity calculated per the volume (3833 mAh/cm3 for magnesium and 2029 mAh/cm3 for lithium) [1]. In addition, magnesium is more common in the earth’s crust (Mg ~ 2.35%, Li ~ 0.0065%), and 20 times cheaper than lithium. However, the main advantage of magnesium is the safety during the process the battery cycling. Charge-discharge cycling on the surface of magnesium, unlike metallic lithium, does not form dendrites [2]. Consequently, there is no danger of short circuits in the inter electrode space and ignition of power sources. Magnesium electrode is a promising anode for various batteries, including batteries with a cathode based on sulfur. The Mg-S batteries will have a much lower self-discharge compared to Li -S batteries.