Selective A‐Site Exsolution and Phase Transition in Perovskite Electrode for Efficient Flexible Znic‐Air Batteries

Abstract Zinc‐air batteries (ZABs) are highly promising for flexible electronics due to their high energy density and cost‐effective. However, their practical application is impeded by the sluggish kinetics of the oxygen evolution and oxygen reduction reactions (OER/ORR). This study presents a novel design featuring BaO nanoparticles anchored on layered perovskite PrBaMn _1.5 Co _0.5 O _6‐δ (PBMC) nanofibers, fabricated through a plasma method. Notably, the plasma treatment induces the selective exsolution of A‐site Ba onto the perovskite surface, while simultaneously driving the transformation of PBMC from a simple perovskite to a layered perovskite, resulting in a unique BaO/PBMC heterostructure. Theoretical calculations demonstrate that the construction of the BaO/PBMC heterojunction regulates interfacial electronic redistribution, thereby lowering energy barriers for both OER and ORR. Consequently, the BaO/PBMC air electrode exhibits superior peak power density and enhanced stability in flexible solid‐state ZABs, compared to the pristine PBMC cathode. Selective A‐site exsolution coupled with phase transition, featuring a unique alkaline‐earth metal oxide/perovskite heterostructure, may offer new insights for energy conversion technologies.