The doping of Ni-rich layered cathodes is an indispensable strategy for addressing their poor ability to support long-term cycling. However, the effect of dopants on the properties of cathode materials is difficult to predict, complicating the development of cathodes with optimized electrochemical performance. This study investigates the effect of dopant (Mo) content and lithiation temperature on the properties of a Ni-rich layered cathode material and electrochemical performance of the resulting cathode. The presence of sufficient Mo affords cathode materials with fine primary particles over a wide lithiation temperature range and increases the temperature at which their crystal structures form during lithiation. It is demonstrated that the electrochemical performance of Mo-doped Ni-rich layered cathodes is largely determined by the secondary particle morphology (primary particle size) and crystallinity of the cathode material. Higher crystallinity and finer primary particles correspond to higher capacity and better long-term cycling performance, respectively. The empirically optimized Mo-doped Ni-rich cathode developed in this study, which is based on a cathode material featuring fine and appropriately crystalline primary particles, is sufficiently mechanically and structurally stable to afford Li-ion batteries with a long cycle life.

富镍层状正极的掺杂是解决其支持长期循环能力差的不可或缺的策略。然而，掺杂剂对正极材料性能的影响难以预测，这使得开发具有优化电化学性能的正极变得复杂。本研究调查了掺杂剂 (Mo) 含量和锂化温度对富镍层状正极材料的性质和所得正极的电化学性能的影响。充足的 Mo 的存在使阴极材料在较宽的锂化温度范围内具有细小的初级颗粒，并增加了在锂化过程中形成晶体结构的温度。结果表明，Mo 掺杂富 Ni 层状正极的电化学性能在很大程度上取决于正极材料的二次粒子形态（一次粒径）和结晶度。更高的结晶度和更细的初级颗粒分别对应于更高的容量和更好的长期循环性能。本研究开发的经经验优化的 Mo 掺杂富镍正极基于具有精细且适当结晶的初级颗粒的正极材料，具有足够的机械和结构稳定性，可提供循环寿命长的锂离子电池。