Atomically dispersed Ir Lewis acid sites on (111)-oriented CeO₂ enable enhanced reaction kinetics for Li-O₂ batteries

Non-aqueous lithium-oxygen batteries are widely regarded as one of the most promising electrochemical energy storage systems, with their ultra-high theoretical energy density and environmental friendliness. However, the sluggish oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) kinetics hinder their practical application. In this study, we tailored an atomically dispersed Ir site on a CeO₂ support (Ir@CeO₂) with {111} facet-dependent activity to enhance cathode reaction kinetics. The charge interaction between Ir and Ce atoms results in the appropriate regulation of the d-band center of Ir sites leaping into the Fermi energy level, demonstrating a stronger Lewis acidity, which enables easier electron injection from the Ir d-orbitals into O 2p-orbitals of LiO₂. This facilitates the conversion kinetics, and as a result, the lithium-oxygen battery with Ir@CeO₂ catalyst delivers a minimal discharge/charge polarization and long-term cycle stability, outperforming most traditional catalysts reported. Our promising findings offer compelling insights into the precise manipulation of d orbital structures and the optimization of Lewis acidity, paving the way for advanced electrocatalyst design.