Investigation of Combined Dopants with Various Oxidation States on Synchronous Regulation of Microstructure and Lattice Robustness of Ni‐Rich Cathode for Lithium‐Ion Batteries

Herein, Ni‐rich‐layered oxides LiNi x Co y Mn 1− x − y O 2 ( x ≥ 0.9) are deemed to be one of the most prospective cathode materials for lithium‐ion batteries as they have the high specific capacity (>200 mAh g −1 ) and high voltage. Much research aiming to conquer capacity decay and thermal instability caused by microcracks is reported. However, the interactive influence of the combined dopants that can modify the oxygen framework robustness and crystallographic texture and are the main factors to inhibit microcracks, is not investigated. Herein, LiNi 0.92 Co 0.05 Mn 0.03 O 2 materials featuring B and dopants with oxidation states from +1 to +4 (Na + , Mg 2+ , Al 3+ , Zr 4+ ) are synthesized to explore the interactive influence of the combined dopants on the structural, morphological, and electrochemical properties and to figure out the optimized dopant combination. It is shown in the results that the modified cathodes with B and higher‐oxidation‐state dopant possess higher radially aligned microstructure and outperformed electrochemical performance, and the cathode with 0.32 mol% Zr and 1.63 mol% B has the initial capacity of 222.9 mAh g −1 and capacity retention of 83.1% after 100 cycles. Herein, a heuristic reference is provided for the development of attractive Ni‐rich cathodes by optimizing dopant combinations to the simultaneous realization of geometry engineering and oxygen framework robustness.