Harnessing 4f Electron Itinerancy for Integrated Dual-Band Redox Systems Boosts Lithium-Oxygen Batteries Electrocatalysis.

In-depth comprehension and manipulation of band occupation at metal centers are crucial for facilitating effective adsorption and electron transfer in lithium-oxygen battery (LOB) reactions. Rare earth elements play a unique role in band hybridization due to their deep orbitals and strong localization of 4 f electrons. Herein, we anchor single Ce atoms onto CoO, constructing a highly active and stable catalyst with d-f a dual-band redox center. It is discovered that the itinerant behavior of 4 f electrons introduces an enhanced spin-orbit coupling effect, which facilitates ideal σ/π bonding and flexible adsorption between the Ce/Co active sites and *O. Simultaneously, the injection of localized Ce 4 f electrons strengthens the orbital bonding capacity of Co-O, effectively inhibits the dissolution of Co sites and improves the structural stability of the cathode material. Bracingly, the Ce1/CoO-based LOB exhibits an ultra-low charge-discharge polarization (0.46 V) and stable cyclic performance (1088 hours). This work breaks through the traditional limitations in catalyst activity and stability, providing new strategies and theoretical insights for developing high-performance LOBs powered by rare-earth elements.