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

Abstract

Abstract Designing high‐activity catalysts and revealing the in‐depth structure–property relationship is particularly important for Li–O 2 batteries. Herein, the self‐boosting catalysis of LiCoO 2 as an electrocatalyst for Li–O 2 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 LiCoO 2 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 LiCoO 2 acts as a catalyst to boost oxygen reduction reaction. During charging, the initial extraction of Li + from LiCoO 2 induces Li/oxygen vacancy and Co 4+ , which deforms CoO 6 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–O 2 batteries with the intercalation/extraction of alkali metal ions in traditional cathodes.