环状磷酸酯作为电解液多功能添加剂的量子化学计算研究

Quantum chemical calculation on cyclic phosphate compounds as multifunctional electrolyte additives

环状磷酸酯作为锂离子电池电解液多功能添加剂倍受关注,研究其结构与性能的构效关系对于相关电解液的组成设计和应用具有重要意义。文章采用量子化学方法计算了15种环状磷酸酯的前线轨道能量、化学硬度、氧化还原电位等量子化学参数,从理论上预测其用作锂离子电池电解液添加剂的可能性。研究了环状磷酸酯分子结构与电化学稳定性之间的关系。计算结果表明:苯环取代不仅可以提高还原电位,还可以显著降低氧化电位和化学硬度,提高分子的反应活性;氟原子取代可以提高分子的还原电位,对氧化电位和化学硬度影响并不明显。

As multifunctional electrolyte additives for lithium-ion batteries, cyclic phosphate com- pounds have attracted much attention. The study of their structure-performance relationship is of im- portance for the composition design and application of electrolyte. In this paper, quantum chemical calculations on 15 kinds of cyclic phosphate compounds were conducted, and the frontier orbital ener- gy, chemical hardiness and redox potentials of the cyclic phosphate compounds were obtained in order to discuss their possibility as multifunctional electrolyte additives in lithium-ion batteries. The rela- tionship between the electrochemical stability and structures of cyclic phosphates was investigated. The results show that phenyl substitution can not only increase the reduction potential of cyclic phos- phates, but also greatly reduce the oxidation potential and chemical hardiness. As a result, the reac- tivity of cyclic phosphates increases. Fluorine substitution can increase the reduction potential of cyclic phosphates, but has negligible effect on the oxidation potential and chemical hardiness.