Unlocking Reversibility of LiOH-Based Li-Air Batteries

Abstract

In this issue of Joule, Clare Grey and colleagues report a nonaqueous electrolyte for Li-air batteries capable of achieving reversible reduction and evolution of oxygen to/from lithium hydroxide in the presence of a redox mediator and added water. Key to unlocking this reversibility is inclusion of ionic liquid, which solvates the redox mediator, modulating its oxidizing power toward LiOH and making O2 formation favorable while disfavoring side reactions. A record faradic efficiency of 99.5% is achieved over the first cycle.