Liao Caijian, Li Fangkun, Liu Jun
Guangdong Provincial Key Laboratory of Advanced Energy Storage Materials, School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641, China.
Nanomaterials (Basel). 2022 May 31;12(11):1888. doi: 10.3390/nano12111888.
Ni-rich cathode materials have become promising candidates for lithium-based automotive batteries due to the obvious advantage of electrochemical performance. Increasing the operating voltage is an effective means to obtain a higher specific capacity, which also helps to achieve the goal of high energy density (capacity × voltage) of power lithium-ion batteries (LIBs). However, under high operating voltage, surface degradation will occur between Ni-rich cathode materials and the electrolytes, forming a solid interface film with high resistance, releasing O, CO and other gases. Ni-rich cathode materials have serious cation mixing, resulting in an adverse phase transition. In addition, the high working voltage will cause microcracks, leading to contact failure and repeated surface reactions. In order to solve the above problems, researchers have proposed many modification methods to deal with the decline of electrochemical performance for Ni-rich cathode materials under high voltage such as element doping, surface coating, single-crystal fabrication, structural design and multifunctional electrolyte additives. This review mainly introduces the challenges and modification strategies for Ni-rich cathode materials under high voltage operation. The future application and development trend of Ni-rich cathode materials for high specific energy LIBs are projected.
由于具有明显的电化学性能优势，富镍正极材料已成为锂基汽车电池的理想候选材料。提高工作电压是获得更高比容量的有效手段，这也有助于实现动力锂离子电池（LIBs）高能量密度（容量×电压）的目标。然而，在高工作电压下，富镍正极材料与电解质之间会发生表面降解，形成具有高电阻的固体界面膜，释放出O、CO等气体。富镍正极材料存在严重的阳离子混合现象，导致不良的相变。此外，高工作电压会导致微裂纹，从而导致接触失效和反复的表面反应。为了解决上述问题，研究人员提出了许多改性方法来应对富镍正极材料在高电压下电化学性能的下降，如元素掺杂、表面涂层、单晶制备、结构设计和多功能电解质添加剂。本综述主要介绍了富镍正极材料在高电压运行下的挑战和改性策略。展望了高比能LIBs富镍正极材料的未来应用和发展趋势。
