Conventional cathode catalysts in lithium–oxygen batteries typically follow the adsorbate evolution mechanism (AEM). In this study, we achieved effective activation of lattice oxygen on the surface of 2D MoO₃ through first-row transition metal doping and propose a lattice oxygen mechanism (LOM) for lithium–oxygen batteries. This mechanism expands the current understanding of reaction pathways and offers a new strategy for reducing the overpotential in lithium–oxygen systems.

Abstract

Lithium–oxygen batteries with ultra-high theoretical energy density are considered promising candidates for next-generation energy storage systems, yet they encounter practical challenges such as high overpotential and poor cycle stability. 2D metal oxides demonstrate promising catalytic performance in lithium–oxygen batteries with high specific surface area. However, the inherent wide bandgaps of 2D metal oxides and the limited microscopic understanding of catalytic processes impede the development of efficient catalyst. Herein, we successfully narrow the bandgap of 2D-MoO₃ by transition metal single-atom doping and unveil the correlation between the electronic property and the geometric distortion caused by the Jahn–Teller effect. Importantly, the lattice oxygen mechanism in lithium–oxygen batteries is first proposed based on the enhanced activity of lattice oxygen on the surface of doped 2D-MoO₃. Our findings offer novel insights into catalyst design for lithium–oxygen batteries, deepen the fundamental understanding of catalytic reaction mechanisms, and pave the way for further exploration in energy storage technology.