应用于锂离子电池的二氟草酸硼酸锂新型锂盐的合成

The synthesis of Lithium Difluoroxalate Borate for Lithium ion Electrolyte

二氟草酸硼酸锂(LiDFOB)作为一种新盐,具有独特的化学结构,在锂离子电池中表现出诸多优异的电化学性能,未来有望取代传统电解质六氟磷酸锂(LiPF6)。本文对市面上已存在的LiDFOB制备路线进行汇总与改进,根据可能的反应机理进行分析,通过探索与正交实验方法,探索一条在实验室完全可以重复的合成路线。通过傅里叶变换红外光谱、X射线衍射进行检测其化学结构,用X射线光电子能谱与化学滴定法定量检测产品纯度,对LiDFOB的制备、提纯与表征进行研究。该方法简易、使用常用玻璃仪器、重复性高,将工业合成方法进行合理简化和创新,本实验为本科生及早参与科研,了解科研最前沿研究内容有重要的推动意义。

Recently,a new type of electrolyte salt,lithium difluorooxalate borate(LiDFOB),is showed to replace the previous lithium hexafluorophosphate(LiPF6),which is sensitive to water,has poor thermal stability,and is not friendly to batteries.Meanwhile,it is synthesized by a variety of processes.However,the reaction conditions are relatively harsh,and the separation method is more complicated.This work utilizes common chemicals in the laboratory,and explores a simple,feasible as well as easy-to-produce route to obtain high-purity battery-grade LiDFOB product after purification.Besides,coming through X-ray diffraction and Fourier transform infrared spectroscopy,we can compare with standard samples.Furthermore,using X-ray photoelectron spectroscopy(XPS)and chemical titration to quantitatively detect product purity,study the preparation,purification and characterization of LiDFOB.Through the research in this article,it provides a theoretical basis for exploring a more convenient preparation route for lithium difluorooxalate borate,and at the same time provides a reference for the application of LiDFOB.