Threefold Modification with Dual-Cation Doping and LiVO3Coating Boosts Long-Term Cyclability and Rate Capability of Li-Rich Cathode Materials for Lithium-Ion Batteries

Li-rich cathode materials are attracting widespread attention owing to their advantages such as high specific capacity and operating voltage. However, irreversible lattice oxygen loss and structural distortion hinder their further commercial application. Herein, a threefold modification strategy with LiVO3surface coating and Na and V dual-cation doping has been utilized to boost the electrochemical performance of Li-rich oxides Li1.2Mn0.54Co0.13Ni0.13O2, which is achieved simply by introducing NaVO3treatment. The LiVO3surface coating prevents interfacial side reactions, promotes Li-ion diffusion kinetics in the interphase, and inhibits irreversible O2release. Additionally, the Na and V dual-cation doping in the bulk can also contribute to boosting Li-ion transfer and restrain irreversible O2evolution. Na-ion doping with the pillar effect expands the lattice space for faster Li-ion intercalation/deintercalation, and V-ion doping by forming stronger V–O bonds further strengthens structural stability. Therefore, the treated Li-rich sample exhibits extended cycle durability and stable voltage stability, with an 82.4% capacity retention rate after 250 cycles and an average voltage fading of 2.4 mV per cycle at 2 C. Moreover, a pouch cell based on the modified Li1.2Mn0.54Co0.13Ni0.13O2@LiVO3cathode presents an outstanding cyclability, maintaining 80.4% of its initial capacity after 400 cycles at 1 C. Our results demonstrate a promising strategy for addressing the issues of Li-rich cathode materials.