Incorporation of foreign elements into the cathode material is broadly adopted by both academia and industry to improve the battery performance. The lack of an in-depth understanding for the underlying mechanism, however, makes it a largely try-and-error process with unsatisfactory efficiency and effectiveness. This is particularly true for the electrochemical reaction kinetics that is heterogeneous over a broad range of length scales and is determined collectively by the cathode’s electronic structure, lattice configuration, and micro-morphology. Here we unveiled a facet-dependent dopant segregation effect in Zr-modified single-crystal LiNi_0.6Co_0.2Mn_0.2O₂ cathode. By forming kinetically favored corners on the cathode particles, the presence of a trace amount of Zr critically modulates the mesoscale reaction kinetics. Our findings suggest that a delicately controlled dopant distribution is a viable strategy for designing the next-generation battery cathode with superior structural and chemical robustness.

学术界和工业界广泛地将异质元素掺入正极材料中以改善电池性能。但是，由于对底层机制缺乏深入的了解，因此使其在很大程度上是一个反复试验的过程，其效率和效果均不令人满意。对于电化学反应动力学来说尤其如此，因为电化学反应动力学在很宽的长度范围内是不均一的，并由阴极的电子结构，晶格构型和微观形态共同决定。在这里，我们揭示了Zr改性单晶LiNi _0.6 Co _0.2 Mn _0.2 O _2中的面依赖性掺杂剂偏析效应阴极。通过在阴极颗粒上形成动力学上有利的角，痕量Zr的存在可关键地调节中尺度反应动力学。我们的发现表明，精心设计的掺杂剂分布是设计具有优异结构和化学稳定性的下一代电池阴极的可行策略。