Layered perovskite oxide PrBaCo₂O_5+δ as a potential cathode for lithium–oxygen batteries: High-performance bi-functional electrocatalysts

Herein, a new type of perovskite oxide PrBaCo₂O_5+δ was synthesized and innovatively applied into Li-O₂ battery (LOB) system as a cathode catalyst, obtained a specific capacity of over 8000 mAh g⁻¹ and sustained more than 1000 cycles at a fixed capacity of 1000 mAh g⁻¹, the number of which approaches and even exceeds most carbon-based Li-O₂ batteries. The charge transfer resistance (R_ct) was tested and resulted in 71 Ω, which was obvious lower than that of BP2000, i.e., 145 Ω. The charging voltage of the PBCO cathode was less than 4 V, resulting in substantially enhanced voltage and energy efficiencies. All these results demonstrated that PrBaCo₂O_5+δ can be a potential bi-functional catalyst in LOB systems.