Cation Segregation of A-Site Deficiency Perovskite La0.85FeO3-δ Nanoparticles toward High-Performance Cathode Catalysts for Rechargeable Li-O2 Battery

Cation segregation of perovskite oxide is crucial to develop high-performance catalysts. Herein, we achieved the exsolution of alpha-Fe2O3 from parent La0.85FeO3-delta by a simple heat treatment. Compared to alpha-Fe2O3 and La0.85FeO3-delta, alpha-Fe2O3-LaFeO3-x achieved a significant improvement of lithium-oxygen battery performance in terms of discharge specific capacity and cycling stability. The promotion can be attributed to the interaction between alpha-Fe2O3 and LaFeO3-x. During the cycling test, alpha-Fe2O3-LaFeO3-x can be stably cycled for 108 cycles at a limited discharge capacity of 500 mAh g(-1)at a current density of 100 mA g(-1) which is remarkably longer than those of La(0.85)Feo(3-delta )(51 cycles), alpha-Fe2O3 (21 cycles), and mechanical mixing of LaFeO3 and alpha-Fe2O3 (26 cycles). In general, these results suggest a promising method to develop efficient lithium-oxygen battery catalysts via segregation.