Uncovering electrochemistries of rechargeable magnesium-ion batteries at low and high temperatures

Rechargeable magnesium ion batteries, which possess the advantages of low cost, high safety, high volumetric capacity, and dendrite free cycling, have emerged as one of the potential contenders alleviate the burden on existing lithium ion battery technologies. Within this context, the electrochemical performance of Mg-ion batteries at high and ultra-low temperatures have attracted research attention due to their suitability for use in extreme environments (i.e. military and space station purposes). To meet the requirements for operation over wide temperature ranges, extensive studies are being conducted to explore different cathodes, anodes, electrolytes, and interfacial phenomena. There is no review that compares the characteristics of magnesium ion batteries in terms of their working mechanism, current challenges, working voltages, possible cathode materials, and resultant electrochemistry at different temperatures. To fulfil this research gap, we summarize the recent advances made in the development of magnesium ion batteries, including high-capacity cathodes, nucleophilic and non-nucleophilic electrolytes, hybrid ion tactics, working mechanisms, their high temperature and ultra-low temperature electrochemical performances. Future recommendations for the development of magnesium ion batteries with high energy densities capable of operating under extreme environmental conditions are also presented.