Structural Reconstruction Driven by Oxygen Vacancies in Layered Ni‐Rich Cathodes

Abstract

Abstract Structure reconstruction induced by the migration of Li, O, and transition metal (TM) ions plays a key role in the performance of Ni‐based cathodes, yet their interactions are still poorly understood. This work investigates systematically the structure transformation of the high‐temperature lithiation in air and oxygen rich atmosphere, charging process, and long‐term storage. Structural and electrochemical characterization of Li‐free/Li‐containing phases (Ni 0.92 Co 0.04 Mn 0.04 (OH) 2 and Li x Ni 0.92 Co 0.04 Mn 0.04 O y ) and a series of detailed analyses provide an in‐depth understanding of the structural reconstruction induced by the interaction of Li, O, and TM ions, i.e., the shift of Li/TM ions in the lattice leads to structural reconstruction via a layered structure with oxygen vacancies.