Electron Itinerancy Mediated by Oxygen Vacancies Breaks the Inert Electron Chain to Boosts Lithium-Oxygen Batteries Electrocatalysis

Abstract

The complex interaction between dopants and oxygen vacancies (Vo) in metal oxides is crucial for enhancing the adsorption and electron transfer processes of Li-O2 batteries. However, the synergetic mechanism among Vo, dopants, and the host matrix remains unclear. Herein, Ru single-atom-modified TiO2 nanorod (Ru1-TiO2-x) with abundant Vo were fabricated, serving as an efficient catalyst for Li-O2 batteries. Experimental and theoretical investigations have demonstrated that Vo as an "electron pump", facilitating electron itinerant behavior, while Ru1 serves as an "electron buffer" to further activate the [Ru-O-Ti] electronic chain, implements the Li-O2 batteries highly active and stable in the process of circulation two-way self-adjusting characteristics. Consequently, the Ru1-TiO2-x-based Li-O2 batteries exhibit an ultra-low charge polarization and stable performance. Vo and Ru1 synergistically coordinate their control over the d-band center at the Ti site to establish a flexible and tunable Ru-Ti dual active site. This adjustment effectively balances the binding strength with the interface oxygen intermediate (*O), thereby significantly reducing the activation barrier. The Hamiltonian layout further revealed the crucial role of remote orbital coupling in maintaining the structural stability. This study provides insights into Vo-dependent electron transfer kinetics and introduces new strategies for activating catalytically inert materials.