LAUSR

Nowadays, lithium-oxygen battery is receiving more and more research attention as the promising nextgeneration rechargeable battery system due to its high energy density (>3500 W h/kg)[1] that is about 10 times higher than that of current lithium-ion batteries. However, the application of lithium-oxygen battery is hindered by several issues such as poor cyclability, limited rate capability and high overpotential during the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER)[2]. What’s worse, the mechanisms of lithium-oxygen battery system are poorly understood due to the highly dynamic nature of this battery system as well as the air-sensitive charge-discharge products that disable most conventional ex situ characterization methods. Consequently, lots of questions are not well answered, such as the formation of complicated discharge products (LiOH, Li2O, Li2O2 LiO2),[3] the detailed nucleation, growth and dissolution processes of lithium oxides during charge and discharge, and the origins for large overpotential.