富镍三元正极材料的改性研究进展

随着便携式电子产品和电动车领域的高速发展，对高能量密度锂离子电池的性能提出了更高的要求。相比传统的钴酸锂正极材料，富镍层状金属氧化物具有较高能量密度和较低的原料成本，被视为理想的锂离子电池正极材料。然而，其结构缺陷和不稳定的表面化学特性会恶化材料的电化学性质、热力学稳定性和安全性能。本文主要回顾了近年来关于富镍三元正极材料的改性研究进展，旨在为今后富镍三元正极材料的设计提供重要思路，并实现其工业化应用。首先，介绍了富镍正极材料本身存在的固有缺陷和电化学性能衰减机制。然后，讨论了通过调控界面结构提升富镍材料性能的改性策略，包括包覆电化学惰性物质、设计元素全浓度梯度及核壳结构、构筑核壳异质结构和调控包覆物质厚度等。再然后，总结了通过元素的体相掺杂提升富镍正极材料性能的策略，包括碱金属位掺杂、过渡金属位掺杂、氧位掺杂和复合共掺杂。最后，我们对该领域的未来发展进行了总结和展望，希望能激发更多创新性的见解和策略，以促进富镍三元正极材料的实际应用。

Research Progress in the Modification of Nickel-rich Cathode Materials

With the rapid development of portable electronic products and electric vehicles, the performance of lithium ion batteries has been put forward higher requirements. Compared with traditional lithium cobalt oxide cathode materials, nickel-rich layered metal oxides have higher energy density and lower raw material cost, and are considered as ideal cathode materials for lithium-ion batteries. However, its structural defects and unstable surface chemical properties will deteriorate the electrochemical properties, thermodynamic stability and safety performance. This paper reviews the research progress of modification of nickel-rich ternary cathode materials in recent years, aiming at providing important ideas for future design of nickel-rich ternary cathode materials and realizing their industrial application. Firstly, the inherent defects of nickel-rich cathode materials and the degradation mechanism of electrochemical performanceare introduced. Then, the modification strategies to improve the properties of nickel-rich materials by adjusting the interface structure were discussed, including coating electrochemical inert substances, designing element concentration gradient and core-shell structure, constructing core-shell heterostructure and controlling the thickness of the coating materials. After that, the strategies to improve the performance of nickel-rich cathode materials by bulk doping of elements are also summarized, including alkali metal-sites doping, transition metal sites doping, oxygen sites doping and synergy co-doping. Finally, we summarized and prospected the future development in this field, expecting to inspire more innovative ideas and strategies to promote the practical application of nickel-rich cathode materials.