Interfacial Colocalized Nucleation of Li2O2 Regulated by Additive-Derived Oxides in Lithium-Oxygen Batteries.

Lithium-oxygen batteries are limited by the morphology of Li2O2 and its decomposition kinetics. Recently, in situ generation of oxides via electrolyte additives has been considered an effective strategy to regulate Li2O2 growth, while the relationship between such oxides and the electrode interface remains unclear. Here, La(NO3)3 is used as an electrolyte additive to generate electrochemically stable La2O3 in situ during discharge. On CNT, La2O3 and Li2O2 nucleate in a dispersed manner on the surface and grow independently, allowing Li2O2 to continuously grow into microsized particles. After introducing a small amount of nanosized Co3O4; however, the two species tend to undergo colocalized nucleation on the Co3O4 surface. Meanwhile, La2O3 imposes a confinement effect on Li2O2 growth, enabling nanosized Li2O2 to decompose at lower voltages and suppressing carbonate byproduct accumulation. As a result, the electrode exhibits lower polarization (reduced by 0.29 V) and more than twice the cycle life.