Octahedral distortion enhances exceptional oxygen catalytic activity of calcium manganite for advanced Zn-Air batteries

Abstract

Calcium manganite (CMO) holds great potential for OER/ORR catalysis. But, the weak interaction between the oxygen intermediates and reaction sites leads to sluggish catalytic kinetics. Herein, to trigger the exceptional catalytic activity of CMO, we propose a thermal-induced MnO 6 octahedral distortion strategy to advance the absorption capability of intermediate reactants. Refined structural analysis and theoretical calculation reveal that the strong Jahn-Teller distortion of MnO 6 is capable of optimizing the surface electron redistribution and accelerating the electron transfer between the oxygen and Mn sites, which significantly boosts the intrinsic oxygen catalytic activities of the distorted CMO (D-CMO). Notably, the D-CMO functions as excellent bifunctional oxygen electrocatalysts and enables a high-performance solid-state Zn-air battery with satisfactory mechanical strength. Specifically, the as-assembled battery displays a remarkable open circuit voltage of 1.46 V and high peak power density of 149 mW cm −2 , even outstripping noble-metal-based counterparts. Modulating the octahedral units to ignite the intrinsic oxygen catalytic activity provides enlightening clues to design perovskite-type air cathodes. • A thermal-induced MnO 6 octahedral distortion strategy is proposed. • The octahedral distortion can optimize electron density and e g electron-filling states. • The octahedron-distortion CaMnO 3 (D-CMO) owns excellent oxygen catalytic activity. • The solid-state ZAB exhibits a high peak power density of 149 mW cm −2 .