Engineering considerations for practical lithium-air electrolytes

Lithium-air batteries promise exceptional energy density while avoiding the use of transition metals in their cathodes, however, their practical adoption is currently held back by their short lifetimes. These short lifetimes are largely caused by electrolyte breakdown, but despite extensive searching, an electrolyte resistant to breakdown has yet to be found. This paper considers the requirements placed on an electrolyte for it to be considered usable in a practical cell. We go on to examine ways, through judicious cell design, of relaxing these requirements to allow for a broader range of compounds to be considered. We conclude by suggesting types of molecules that could be explored for future cells. With this work, we aim to broaden the scope of future searches for electrolytes and inform new cell design. We consider the requirements to be placed on an electrolyte for it be used in a practical lithium-air battery. Ways to ease these requirements by refining cell design and improving transport as well as motifs for future electrolytes are discussed.