Trifunctional imidazolium bromide: a high-efficiency redox mediator for high-performance Li–O2 batteries

Abstract

In this work, 1-aminopropyl-3-methylimidazolium bromide (APMImBr) is introduced in dimethyl sulfoxide-based Li–O₂ batteries. The Br⁻ functions as a redox mediator to catalyze the decomposition of the Li₂O₂ 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 Li₃N-rich solid electrolyte interface layer. As a result, the Li–O₂ 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.