锂离子电池富镍正极基础科学问题：关键元素掺杂及其作用机理

Basic scientific problems of nickel rich cathode materials for Li-ion battery: key element substitution and its mechanism

摘要:

富镍层状氧化物因其相对较高的比容量成为高能量密度锂离子电池的首选正极，进一步提高Ni含量，材料特性趋向于LiNiO2，电化学和结构稳定性恶化。晶格元素掺杂是提升LiNiO2稳定性的有效策略。厘清LiNiO2正极材料结构并明晰掺杂元素对其影响及规律，对开发Ni含量大于90%的富镍正极材料具有重要意义。本文首先介绍了LiNiO2材料结构及面临的稳定性问题。然后综述了Co、Mn、Al、Mg、Ti、Zr、W等典型掺杂元素对LiNiO2的影响及规律，并讨论了阴离子和多元素掺杂以及有潜力的掺杂元素。本文旨在对LiNiO2掺杂提供一个新的视角，以期使用更有效的掺杂方案开发可用于动力电池的高容量稳定的富镍正极材料。

Abstract:

Nickel-rich layered oxides have become the preferred cathodes for high-energy-density Li-ion batteries due to their relatively high specific capacity, further increasing the Ni content, the material properties tend to be LiNiO2, and the electrochemical and structural stability deteriorate. Lattice element doping is an effective strategy to improve the stability of LiNiO2. Clarifying the structure of LiNiO2 cathode material and clarifying the influence and regularity of doping elements on it is of great significance for the development of nickel-rich cathode materials with Ni content greater than 90%. In this paper, the structure of LiNiO2 material and the stability problems it faces are firstly introduced. Then, the influences and laws of typical doping elements such as Co, Mn, Al, Mg, Ti, Zr, and W on LiNiO2 are reviewed, and anionic and multi-element doping and potential doping elements are discussed. This paper aims to provide a new perspective on LiNiO2 doping with a view to developing high-capacity stable Ni-rich cathode materials for power batteries using more efficient doping schemes.