Probing the Self‐Boosting Catalysis of LiCoO2 in Li–O2 Battery with Multiple In Situ/Operando Techniques

Designing high‐activity catalysts and revealing the in‐depth structure–property relationship is particularly important for Li–O₂ batteries. Herein, the self‐boosting catalysis of LiCoO₂ as an electrocatalyst for Li–O₂ batteries and the investigation of its self‐adjustment mechanism using in situ X‐ray absorption spectroscopy and other operando characterization techniques is reported. The intercalation/extraction of Li⁺ in LiCoO₂ not only induces the change in Co valence and modulates the electronic/crystal structure but also tunes the surface disorder degree, lattice strain, and local symmetry, which all affect the catalysis activity. In a discharge, highly ordered LiCoO₂ acts as a catalyst to boost oxygen reduction reaction. During charging, the initial extraction of Li⁺ from LiCoO₂ induces Li/oxygen vacancy and Co⁴⁺, which deforms CoO₆ octahedron as well as lowers the symmetry, and accordingly promotes oxygen evolution reaction. This article offers insights into tuning the activity of catalysts for Li–O₂ batteries with the intercalation/extraction of alkali metal ions in traditional cathodes.