Ni‐rich layered lithium metal oxides are the cathode active materials of choice for high‐energy‐density Li‐ion batteries. While the high content of Ni is responsible for the excellent capacity, it is also the source of interfacial instability, limiting the material's lifetime due to a variety of correlated in‐ and extrinsic factors. Hence, reconciling the opposing trends of high Ni content and long‐term cycling stability by modifying the material's surface is one of the challenges in the field. Here, we review various studies on surface modification of Ni‐rich (≥ 80 %) layered cathode active materials in order to categorize current research efforts. Broadly, the three strategies of coating, surface doping and washing are discussed, each with their advantages and shortcomings. In conclusion, we highlight new directions of research that could bring Ni‐rich layered lithium metal oxide cathodes from the laboratory to the real world.

中文翻译：

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提高富镍正极材料循环性能的表面改性策略

富镍层状锂金属氧化物是高能量密度锂离子电池的首选正极活性材料。虽然高含量的 Ni 是优异容量的原因，但它也是界面不稳定的来源，由于各种相关的内在和外在因素，它限制了材料的寿命。因此，通过改变材料表面来调和高镍含量和长期循环稳定性的相反趋势是该领域的挑战之一。在这里，我们回顾了对富镍（≥ 80 %）层状正极活性材料进行表面改性的各种研究，以便对当前的研究工作进行分类。从广义上讲，讨论了涂层、表面掺杂和洗涤三种策略，每种策略都有其优点和缺点。综上所述，