Trifunctional imidazolium bromide: a high-efficiency redox mediator for high-performance Li-O 2 batteries.

In this work, 1-aminopropyl-3-methylimidazolium bromide (APMImBr) is introduced in dimethyl sulfoxide-based Li-O 2 batteries. The Br - functions as a redox mediator to catalyze the decomposition of the Li 2 O 2 products. Meanwhile, the APMIm + serves as a scavenging agent for superoxide radicals as well as protects the lithium metal anodes via an in situ formed Li 3 N-rich solid electrolyte interface layer. As a result, the Li-O 2 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.