单晶高镍三元正极材料研究进展

Research Progress of Single Crystal Ni-rich Ternary Cathode Materials

高镍系三元正极材料(Ni≥60%)因高能量密度、低毒性、低污染性和低廉的价格成为当前锂离子电池体系中最具发展潜力的电池材料之一。目前,商用的高镍系三元正极材料多为团聚型的多晶材料,团聚型的多晶材料在充放电过程中由于体积膨胀会出现微裂纹,导致电极材料与电解液反应加剧,进而引起结构坍塌,研究表明,微裂纹的产生是高镍三元正极材料(Ni≥60%)在使用过程中容量衰退的主要原因。而单晶高镍三元正极材料由于无内部晶界可彻底解决微裂纹产生的问题,备受国内外广大专家、学者的关注。此外,其较高的压实密度、良好的热稳定性、长循环寿命也让其具有进一步替代多晶材料的潜力。本文结合单晶高镍正极材料行业现状,对其采用不同的制备方法进行归纳,为企业的前沿布局提供了借鉴和参考。

Ni-rich ternary cathode material(Ni≥60%)has become one of the most promising battery materials due to its high energy density,low toxicity,low pollution and low price.At present,most of the commercial Ni-rich ternary cathode materials are agglomerated polycrystalline materials.Polycrystalline materials will produce microcracks due to the volume expansion,which result in more side effects be-tween cathode materials and electrolyte,then,cause structural collapse.The research shows that microc-racks are the main reason for the capacity decline of Ni-rich ternary cathode materials(Ni≥60%).Sin-gle-crystal cathode materials can solve the problem due to the absence of internal grain boundaries.In ad-dition,because of the high compaction density and good thermal stability,the single crystal Ni-rich terna-ry cathode material has attracted the attention of experts and scholars at home and abroad.In this paper,based on the current situation of single-crystal Ni-rich cathode materials industry,the different prepara-tion methods are summarized,which provides reference for the cutting-edge layout of enterprises.