Stabilization of Lattice Oxygen in Li‐Rich Mn‐Based Oxides via Swing‐like Non‐Isothermal Sintering

Abstract

AbstractRedox from the holes at the O2p orbitals is a well‐known phenomenon in Li‐rich Mn‐based batteries. However, such an anionic redox process results in the formation of O2, leading to structural instability owing to unstable O2p holes. Herein, a swing‐like non‐isothermal sintering technique is used to stabilize the lattice oxygen by suppressing the formation of O2 during charging. It reduces both the number of intrinsic oxygen vacancies of the Li‐rich Mn‐based oxides and the formation of O2 during charging as compared with traditional constant high‐temperature sintering. Consequently, the number of holes generated during charging in the O2p orbitals increases, whereas the number of unstable O2p holes forming O2 decreases. Therefore, the sample prepared via swing‐like non‐isothermal sintering exhibited considerably slower voltage fading and better cycling stability. This study provides valuable guidelines for stabilizing the lattice oxygen and improving the structural stability of the oxide cathodes for electrochemical energy storage.