Although conventional monometallic oxide coating on lithium nickel cobalt manganese oxide (NCM) cathode materials has been extensively investigated, there are still many issues, such as low electrical conductivity, poor mechanical properties and inferior chemical stability, that need to be addressed. Indeed, because of the single nature of monometallic oxides, it is difficult to achieve the synergistic effect of various properties. In this work, NiCo₂O₄ were rationally grown on the surface of commercial LiNi_0.8Mn_0.1Co_0.1O₂ (NCM811) to obtain a bimetallic oxide coated NCM811 as cathode material for Lithium ion batteries (LIBs). This cleverly designed coating with a higher electronic and ionic conductivity, better bulk modulus, and an outstanding interfacial stability, could improve the capacity retention to 90.97% after 200 cycles at 100 mA g⁻¹ and enhance the initial coulombic efficiency (CE) to 82.92%. The electrochemical characterization further clarifies the indisputable benefits of NiCo₂O₄ coating to enhancement of the cathode performance. Moreover, the theoretical calculations provide more explanations in three aspects, including mechanical stability, chemical stability and electrical properties, confirming the superiority of NiCo₂O₄ bimetallic oxide coating with multiple properties over the monometallic one. More importantly, this study has profound implications in the design of bimetallic and polymetallic oxide coatings for electrode materials, and even other bimetallic coatings, such as sulfides and selenides, in the future.

尽管已经对锂镍钴锰酸锂（NCM）阴极材料上的常规单金属氧化物涂层进行了广泛研究，但仍然需要解决许多问题，例如电导率低，机械性能差和化学稳定性差。实际上，由于单金属氧化物的单一性质，难以实现各种性质的协同作用。在这项工作中，NiCo ₂ O ₄合理地生长在商用LiNi _0.8 Mn _0.1 Co _0.1 O ₂的表面上（NCM811）获得涂覆双金属氧化物的NCM811作为锂离子电池（LIB）的阴极材料。这种设计巧妙的涂层具有更高的电子和离子电导率，更好的体积模量以及出色的界面稳定性，在100 mA g ^-1下200次循环后，容量保持率可提高至90.97％，并将初始库仑效率（CE）提高至82.92 ％。电化学表征进一步阐明了NiCo ₂ O ₄涂层对提高阴极性能的无可争议的好处。此外，理论计算在机械稳定性，化学稳定性和电性能三个方面提供了更多的解释，证实了NiCo ₂ O ₄的优越性。在单金属涂层上具有多种性能的双金属氧化物涂层。更重要的是，这项研究对电极材料的双金属和多金属氧化物涂层的设计，甚至将来的其他双金属涂层（例如硫化物和硒化物）的设计都具有深远的意义。