Trifunctional imidazolium bromide: a high-efficiency redox mediator for high-performance Li-O batteries.

In this work, 1-aminopropyl-3-methylimidazolium bromide (APMImBr) is introduced in dimethyl sulfoxide-based Li-O batteries. The Br functions as a redox mediator to catalyze the decomposition of the LiO products. Meanwhile, the APMIm serves as a scavenging agent for superoxide radicals as well as protects the lithium metal anodes an formed LiN-rich solid electrolyte interface layer. As a result, the Li-O batteries containing APMImBr delivered an enlarged discharge capacity, a reduced charge overpotential of around 0.61 V and a prolonged cyclic life of over 200 cycles.