富镍正极材料，具有原料来源广、理论比容量高、电压平台高等优点，被认为是汽车用动力电池的首选正极材料。随着镍含量提高，材料的理论比容量随之提升，但其结构稳定性变差，严重损害材料电化学性能。针对这一难题，本项目独辟蹊径，提出利用富镍材料中的“Li+/Ni2+阳离子混排”现象，通过在表面引入高价阳离子作为诱导源，基于电荷平衡，在特定条件下，诱导材料表层中部分Ni3+转变为Ni2+，使Ni2+与部分Li+发生混排，在表面形成NiO岩盐相结构。一方面利用表面形成的NiO作为缓冲层，隔绝材料与电解液的直接接触，抑制副反应；另一方面岩盐相NiO层具有特殊的锂离子传输性能，可提升富镍材料的导电性。重点研究原位诱导反应机理，明确支撑层中锂离子和电子的传输行为及调控规律，阐明岩盐相表层结构在稳定富镍材料结构及促进锂离子传输的作用机理。为合成结构稳定的高性能富镍材料提供理论参考和技术原型。

Nickel rich nickel rich cathode materials has been considered one of the most promising candidates of cathode material for next-generation electric vehicles. However, with the nickel increasing, the structure of the material become unstable, which will damage the electrochemical performance and increase the safety risk of battery. To solve this dilemma, a novel method has been proposed to stabilize the structure and improve the electrochemical performance of the material. “Cation mixing phenomenon” is taken use to solve the above dilemma by introducing high valence cation to the surface of the material, to induce some of the Ni3+ change to Ni2+, and form a stable NiO layer with a Fm-3m structure. The NiO can not only prevent the material from directly contact with electrolyte, but also improve the lithium diffusion efficiency. The NiO formation mechanism will be clarified, and the effect mechanism will be also revealed. The relationship between structure properties and the electrochemical performances will be built. This research will provide theoretical reference and technology prototype for understanding and synthesizing high performance nickel rich cathode materials for lithium ion battery.