Ni-rich cathode materials have become the main research focus in the field of Li-ion batteries due to the urgent need for cathode materials with higher weight and volume energy density for application of Li-ion batteries in electric vehicles. However, the conditions for the preparation of these materials are harsh, they are unstable during storage in air, and problems like capacity fading and structure deterioration are hard to overcome. All these drawbacks are related to Li/Ni disorder and NiO-like phases, which cover the surface of Ni-rich cathode materials. In this article, the influence of NiO-like phases on the electrochemical properties of Ni-rich cathode materials during preparation, cycling, and storage in air is studied, and a formation mechanism for NiO-like phases is proposed. The results confirm that the amount of NiO-like phases, especially on the surface, must be reduced for the preparation of Ni-rich cathode materials with high performance.

富镍正极材料已成为锂离子电池领域的主要研究重点，这是因为迫切需要用于电动汽车的锂离子电池具有更高重量和体积能量密度的正极材料。然而，这些材料的制备条件很苛刻，在空气中储存期间不稳定，并且难以克服容量衰减和结构劣化等问题。所有这些缺点与Li / Ni无序和类似NiO的相有关，这些相覆盖了富Ni阴极材料的表面。本文研究了NiO类相对富Ni正极材料在制备，循环和在空气中存储过程中电化学性能的影响，并提出了NiO类相的形成机理。结果证实了类似NiO的相的数量，