锂离子电池正极材料生产技术的发展

Manufacturing method for cathode materials of Li-ion batteries

本文对锂离子电池正极材料生产制备技术的发展历史进行了回顾,对锂离子电池正极材料的发展方向进行了分析。20世纪末,从锂离子电池正极材料加工性能和电池性能的角度出发,清华大学研究团队提出了控制结晶制备高密度球形前驱体的技术,结合后续固相烧结工艺,提出了制备含锂电极材料的产业技术。其中,控制结晶方法制备前驱体,可以在晶胞结构、一次颗粒组成与形貌、二次颗粒粒度与形貌,以及颗粒表面化学4个层面对材料的性能进行调控与优化。利用该技术工艺生产的材料具有颗粒粒度及形貌易控制、均匀性好、批次一致性和稳定性好的特点,可以同时满足电池对于材料电化学性能和加工性能的综合要求。因材料的堆积密度高,尤其适用于高比能量电池。该技术工艺适用于多种正极材料,并适合于大规模生产,随着时间的推移,逐步被证明是锂离子电池正极材料的最佳生产技术工艺,得到了现今产业界的普遍接受和认可。这也是我国科学工作者对国际锂离子电池产业做出的重要贡献之一。

This paper reviews manufacturing technologies for cathode materials of lithium ion batteries and discusses the development trend of such materials. Specific attention is paid to the work at Tsinghua University where a novel solid state process was developed. The keys to such a process are an optimized precursor by controlled crystallization. The optimization of the material properties was done from four aspects of crystal cell structure, primary particle structure, secondary particle morphology and the surface chemistry, enabling the products with a controlled size, uniformity, consistency, scale-up and reproducibility. Moreover, the bulk density of the material is high and hence a high energy density of batteries. This technical route of controlling crystallization/solid state reaction has been accepted by the industry, which represents one of the most important contributions to the lithium-ion battery industry.