Surface modification plays a vital role in improving the rate performance and cycling stability of layered Ni-rich LiNi_0.6Co_0.2Mn_0.2O₂ (NCM622) cathode materials for Li-ion batteries. In this study, Li₂MgTi₃O₈ (LMTO)-coated NCM622 was successfully synthesized by wet coating combined with sintering process. The results of morphological analysis showed a uniform LMTO layer coated on the surface of NCM622 materials. The dual ions of Ti⁴⁺ and Mg²⁺ on surface structure of NCM622 were identified by X-ray diffraction and X-ray photoelectron spectroscopy. The surface coating layer prevented the direct contact between the active cathode material and the electrolyte which significantly reduced the side reactions, and the doping of Ti⁴⁺ and Mg²⁺ improved the structural stability of the NCM622 materials. The electrochemical performance indicates that NCM622 cathode with a coating layer of 0.5 wt% LMTO exhibited excellent cycle stability and maintained a capacity retention up to 76% after 200 cycles at 25 °C at 1 C-rate, which was higher than the value of 52% for the NCM622.

表面改性在改善锂离子电池用层状富镍NiNi _0.6 Co _0.2 Mn _0.2 O ₂（NCM622）正极材料的倍率性能和循环稳定性方面起着至关重要的作用。本研究通过湿法涂层结合烧结工艺成功合成了Li ₂ MgTi ₃ O ₈（LMTO）涂层的NCM622。形态分析的结果表明，在NCM622材料的表面上涂覆了均匀的LMTO层。Ti ⁴⁺和Mg ²⁺的双离子用X射线衍射和X射线光电子能谱鉴定了NCM622的表面结构。表面涂层阻止了活性阴极材料与电解质之间的直接接触，从而大大减少了副反应，并且Ti ⁴⁺和Mg ²⁺的掺杂提高了NCM622材料的结构稳定性。电化学性能表明，具有0.5 wt％LMTO涂层的NCM622阴极表现出优异的循环稳定性，并在25°C下以1 C速率进行200次循环后，其容量保持率高达76％，高于52的值。 NCM622的％。