Collaboratively enhancing electrochemical properties of LiNi <sub>0.83</sub> Co <sub>0.11</sub> Mn <sub>0.06</sub> O <sub>2</sub> through doping and coating of quadrivalent elements
Zhaozhe Yu, Gui-Quan Zhao, Fangli Ji, Hao Tong, Qilin Tong, LI Hua-cheng, Yan Cheng
Abstract
Abstract Ni‐rich layered oxides (Ni ≥ 80%) with high energy density have become a mainstream cathode material for Li‐ion batteries. However, irreversible phase transitions and interface instability are deep‐seated challenges in commercializing Ni‐rich materials. This study used a collaborative modification strategy involving doping and coating with quadrivalent elements to construct Ni‐rich materials. In particular, introducing tetravalent Zr makes the valence change of Ni (2+ to 4+) more accessible to complete spontaneously during the charging and discharging processes, which significantly suppresses the cationic mixing and irreversible phase transition (H2 ↔ H3). Combining the strategy of constructing CeO 2 coatings on the surface and interfacial spinel‐like phases improves the Li + diffusion kinetics and interfacial stability. Simultaneously, part of the strongly oxidizing four‐valence Ce 4+ diffuses to the surface layer, further increasing the average valence state of Ni. Therefore, LiNi 0.83 Co 0.11 Mn 0.06 O 2 (NCM)‐Zr@Ce achieves 78.5% outstanding retention at 1.0C after 200 cycles within 3.0–4.3 V compared to unmodified NCM with 41.4% retention. The improved cyclic stability can be attributed to the collaborative modification strategy of the quadrivalent elements, which provides an effective synergistic modification strategy for developing high‐performance Li‐ion battery cathode materials.