锂盐与特定溶剂的相互作用机理研究

基于锂盐溶解于EC、EMC等有机溶剂会降低这些有机溶剂的氧化分解电位，从而导致锂离子电池电解液高电压耐受性差的事实。本项目从盐湖锂资源制备的锂离子电池电解质锂盐出发，制备高电压耐受溶剂，采用电化学石英微天平和在线红外光谱等手段，研究较高充电电压下，锂盐在特定的不同有机溶剂中的配位环境变化；利用溶剂分子轨道能量与其氧化分解电位之间的联系，通过分子模拟的方法研究电解质锂盐的溶解对溶液的氧化分解电位的影响，并探明其分解机理；同时选择合适的功能添加剂以提高制备的高电压电解液的电化学性能；最后研究电解液与正负极材料之间的相容性，以期得到体系优化的锂离子电池用高电压电解液材料。通过本项目的研究，将使得盐湖锂资源应用实现高值化开发，推动高能锂离子电池的发展。

Based on the fact that dissolving lithium salt in EC, EMC, and other organic solvents will reduce the oxidation decomposition potential of the organic solvent, result in the poor voltage tolerance of lithium ion battery electrolyte. Lithium resources from the Saline Lake will be prepared and used as raw material to prepare high voltage tolerance electrolyte for high energy lithium ion battery. Electrochemical quartz crystal microbalance and online infrared spectroscopy will be applied to detect the coordination environment changes of lithium ion in different specific organic solvents under high charging voltages. Considering the decomposition potential of solvent is impacted by its molecular orbital energy, molecular simulation will be employed to study the decomposition mechanism. Appropriate functional additives will be chosen to improve the electrochemical performance of high voltage electrolyte prepared. The compatibility between the electrolyte and the cathode and anode will be studies in order to optimize the composition of high voltage electrolyte for lithium ion battery system. Through the research of this project, it will make the development of the high value of lithium resources in Saline Lake, and promote the development of high energy lithium ion battery.