Rational design of La0.6Ba0.4Ti0.2Fe0.3+xNi0.5-xO3-δ (x = 0, 0.2, 0.4) perovskite oxides as bifunctional electrocatalysts for high-efficiency zinc-air batteries

Perovskite oxides represent a class of cost-effective alternatives to precious metal catalysts (Pt, Ir, Ru) while demonstrating comparable catalytic performance. Their intrinsic dual-functional electrocatalytic capabilities for both oxygen reduction (ORR) and oxygen evolution reactions (OER) make them promising cathode candidates for rechargeable zinc-air batteries. In this work, a series of B-site modulated perovskite catalysts with the composition La 0.6 Ba 0.4 Ti 0.2 Fe 0.3+x Ni 0.5-x O 3-δ (denoted as LBTFN-x, where x = 0, 0.2, and 0.4) were synthesized via a sol-gel method to systematically investigate the Fe/Ni ratio optimization for enhanced battery performance. Structural and compositional characterization was performed using X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) specific surface area analysis, and X-ray photoelectron spectroscopy (XPS). The electrocatalytic activities toward ORR and OER were systematically evaluated through rotating disk electrode (RDE) measurements in alkaline electrolyte. Notably, the LBTFN-0 catalyst exhibited optimal electrochemical performance for ORR and OER, outperforming its counterparts with higher Fe/Ni ratios. When implemented as a cathode in zinc - air batteries under alkaline conditions, LBTFN-0 demonstrated superior charge-discharge performance and cycling stability. These findings highlight LBTFN-0 as a highly efficient and durable bifunctional catalyst for metal-air battery systems, providing new insights into the design of high-performance perovskite-based electrocatalysts for energy storage applications.