Mechanistic insights into LYNF perovskite zinc–air battery

In this work, we aimed to comprehend the mechanistic fundamental for the cathode catalyst La0.85Y0.15Ni0.7Fe0.3O3 (LYNF) in the zn-air battery. First, the LYNF was synthesized and explored for its electrochemical performance.The results reveal that the Y/Fe substitution significantly enhances the bifunctional catalytic behaviour of LaNiO₃, demonstrating a significantly high discharge capacity of 10477 mAhg-1catalyst at a current density of 50 mAg⁻¹ within the potential window of 1.0 – 2.0 V vs. Zn2+/Zn.Further to have mechanistic insight for the enhanced performance of LYNF, the in-situ Raman spectroscopy was performed, that depicts LYNF followed a bidentate pathway for the discharge phase and the corresponding lattice oxygen mechanism (LOM) for the charge phase attributed to the presence of superoxide peak (1130cm-1), during ZAB operation. The identified peak reveals the oxygen vacancies serve as the primary active centres in the double-perovskite.Moreover, to support the experimental observation, the computational approach has been employed by using density functional theory (DFT). The electronic structure was analysed in terms of DOS and PDOS of LaNiO3 and LYNF, which reveals that Y/Fe substitution enhances the metal–oxygen covalency and thus improved bifunctional activity of the LYNF.Thus, this work provides insight into the development of the next generation reversible zinc-air batteries, via comprehending the underlying mechanism during the battery operation, and opens up new opportunities to explore the perovskites for metal-air battery applications.