Cation Segregation of A-Site Deficiency Perovskite La_0.85FeO_3−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 α-Fe 2 O 3 from parent La 0.85 FeO 3−δ by a simple heat treatment. Compared to α-Fe 2 O 3 and La 0.85 FeO 3−δ, α-Fe 2 O 3 -LaFeO 3– 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 α-Fe 2 O 3 and LaFeO 3– x . During the cycling test, α-Fe 2 O 3 -LaFeO 3– 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−δ (51 cycles), α-Fe 2 O 3 (21 cycles), and mechanical mixing of LaFeO 3 and α-Fe 2 O 3 (26 cycles). In general, these results suggest a promising method to develop efficient lithium-oxygen battery catalysts via segregation.