Atomically Asymmetrical Ruthenium-Oxygen-Cobalt Sites Accelerate Oxygen Redox and Suppress Side Reactions for Stable Lithium-Oxygen Batteries.

Li, Yajing; Qiu, Yuan; Wang, Yingli; Wang, Lei; Lv, Qingliang · ACS Nano · 2025

basic_science · Level V

Where this comes from

Abstract

Development of aprotic lithium-oxygen (Li-O<sub>2</sub>) batteries suffers from slow cathode reaction kinetics, numerous side reactions, and large polarization, which are intimately related to the discharge product of Li<sub>2</sub>O<sub>2</sub>. Here, we designed and prepared a modified Co<sub>3</sub>O<sub>4</sub> nanoparticle with atomic Ru substitution at octahedral Co sites supported by carbon nanocages (RuCoO<sub><i>x</i></sub>@HCNs) as a cathode catalyst. The asymmetrical octahedral Ru-O-Co units trigger a strong electron coupling effect, leading to charge redistribution and optimization of the d-orbital energy levels, thus facilitating oxygen activation and conversion into superoxide anions during discharging. More importantly, the Ru-O-Co units manifest high affinity for the intermediate LiO<sub>2</sub>, inducing the rapid formation of unique nanoneedle-like Li<sub>2</sub>O<sub>2</sub> on RuCoO<sub><i>x</i></sub>@HCNs, avoiding the accumulation of byproducts and accelerating its decomposition during charge. These merit the Li-O<sub>2</sub> battery with RuCoO<sub><i>x</i></sub>@HCNs to deliver a reduced polarization of 0.96 V and a prolonged lifespan of over 2200 h.