Nd Doping Inhibits Lattice Oxygen Loss to Enhance High‐Voltage Durability of Ni‐Rich Cathodes

Abstract Ni‐rich layered oxides (Ni > 90%) are promising next‐generation lithium‐ion battery cathodes, offering high specific capacity and low cost. However, their structural instability and oxygen evolution at high voltages limit practical application. Here, Nd‐doped LiNi₀.₉₀Co 0.05 ;Mn 0.05 O 2 (NCM9055‐Nd) is successfully synthesized via a facile sintering method. Combined sXAS, in situ XRD, TOF‐SIMS, in situ DEMS, and DFT analyses reveal that Nd 3 ⁺ doping effectively suppresses unit cell volume change and inhibits oxygen vacancy formation, even at a high cut‐off voltage of 4.6 V. Consequently, the NCM9055‐Nd cathode exhibits significantly enhanced cycling stability, retaining 65.6% capacity after 300 cycles at 2 C–a substantial improvement over the undoped material (46%). Moreover, it delivers an impressive high‐rate discharge capacity of 133.7 mAh g −1 at 5 C. This work demonstrates Nd doping as an effective strategy for developing high‐performance, structurally stable Ni‐rich, Co‐low cathodes for advanced lithium‐ion batteries.