锂离子电池高镍三元正极材料LiNi0.8Co0.1Mn0.1O2研究进展

锂离子电池具有循环寿命高、无记忆效应等优点, 被广泛应用于电子消费产品及电动汽车等诸多领域。伴随着国内电动汽车的快速发展, 对锂离子电池的能量密度、安全性能、成本、热稳定性、循环寿命等提出了更高的要求。电池性能的提升取决于电极材料的改善, 而正极材料作为锂离子电池的核心组成部分, 将直接影响整个电池的性能。高镍三元正极材料LiNi_0.8Co_0.1Mn_0.1O₂(以下简称为NCM811)由于极高的放电比容量(>200 mAh/g)而吸引了越来越多人的关注。但是, NCM811较差的热稳定性、循环倍率性以及安全性限制了它在实际中的大规模应用。本文结合NCM811的晶体结构、合成方法以及目前存在的主要问题, 阐述了近几年国内外改善NCM811的电化学性能研究, 并重点介绍表面包覆、离子掺杂和添加剂改性技术对NCM811电化学性能的影响。

Research Progress of High Nickel Ternary Cathode Material LiNi0.8Co0.1Mn0.1O2 for Lithium-ion Batteries

Lithium-ion batteries (LIBs) are widely used in many fields such as electronic products and vehicles due to their long-term cycling and no-memory effect. With the rapid development of domestic electric vehicles, higher requirements are put forward for the energy density, safety performance, cost, thermal stability, and cycle life of lithium-ion batteries. However, the battery performances depend deeply on the improvement of electrode materials. As the key component of LIBs, the cathode materials will directly affect the battery performances. Therefore, the nickel-rich LiNi_0.8Co_0.1Mn_0.1O₂ cathode (hereinafter referred to as NCM811) has attracted more and more attention owing to its extremely high discharge capacity (> 200 mAh/g). However, the poor thermal stability, cycle rate, and safety of NCM811 restrict its large-scale application in practice. Combining the crystal structure, synthesis method and current main problems of NCM811, the improving technology is summarized for electrochemical performance of nickel-rich NCM811 in recent years, focusing on the surface coating, ion doping and additive modification.