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

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 (Ni0.92Co0.04Mn0.04(OH)2 and LixNi0.92Co0.04Mn0.04Oy) 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. Structural reconstruction during the synthesis, storage, and cycling of Ni‐rich cathode materials is mainly driven by oxygen vacancies in the layered structure. This result provides a theoretical guidance for the calcination and modification of cathode materials, i.e., the calcination environment should ensure sufficient oxygen, and the doped elements should be selected with strong TM‐O bonds.