Orbital Charge Exchange Transition Conceptually Activates Multi‐Bifunctional Li–O ₂ and Li–CO ₂ Pathways at Deep and Shallow Energy Levels in Li–Air Batteries

Abstract

Abstract In Li‐air batteries (LABs), the deep and shallow orbital distributions of reactants in Li–O 2 and Li–CO 2 pathways in ambient air pose a conceptual predicament for designing cathode catalysts that can precisely activate multi‐functional electrocatalysis at different energy levels with a large energy gap. Following the design guideline of optimizing deep and shallow band structures, an orbital charge exchange transition strategy was applied to tailor the electronic structure of Ce 2 Mo 3 O 12 as a potential catalyst. Theoretical investigation predicts the oxygen vacancy‐induced ligand rearrangement tendency and the orbital charge exchange transition from a f‐p‐f super exchange between Ce─O─Ce sites to a f‐p‐d double exchange mode between Ce─O─Mo hetero‐sites. This motivates the low‐lying Ce 2e orbitals for Li–O 2 pathways and gains a charge‐filled shallow Mo d‐band for Li–CO 2 pathways. Importantly, the XANES and related electronic and crystal structure analysis, quantitative electrocatalysis investigation and high battery performance perfectly identify the reliability of the theoretical prediction. Consequently, the Ce 2 Mo 3 O 12 cathode exhibited stable operation for nearly 600 cycles in ambient air with excellent humidity tolerance and an impressive energy density of 1560 Wh kg −1 for pouch cells as power sources of electric devices, marking a significant step for the practical application of LABs.