电解质
溶剂化
离子液体
化学
玻璃化转变
离子电导率
锂(药物)
酰亚胺
离子
分子动力学
无机化学
物理化学
计算化学
有机化学
聚合物
医学
电极
内分泌学
催化作用
作者
Drace Penley,H. Gerber,Mounesha N. Garaga,Nalinda P. Wickramasinghe,Steven Greenbaum,Edward J. Maginn,Yong Zhang,Burcu Gurkan
标识
DOI:10.1016/j.jpowsour.2023.233984
摘要
The thermal, physical, structural, and transport properties of ionic liquid (IL) electrolytes based on n-methyl-n-butylpyrrolidinium bis(trifluoromethanesulfonyl)imide [PYR14][TFSI] and Li-salts of lithium (nonafluorobutane)(trifluoromethanesulfonyl)imide [Li][IM14] and [Li][TFSI] (0 ≤ xLi ≤ 0.3), with addition of 1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether (TTE) (0 ≤ xTTE ≤ 0.45) were studied. While [IM14] increases glass transition, TTE improves conductivity over a wider liquidus range. Li+ is solvated primarily by [TFSI] with some contribution by [IM14]. However, both 7Li- 19F HOESY NMR and spatial distribution functions (SDFs) derived from molecular dynamics (MD) indicate short contacts between the fluorines of TTE and Li+. This is a result of tighter anion-solvated Li+ without aggregation of the Li+ solvates, consistent with Raman measurements, thus confirming the existence of fluorous domains in the bulk which leads to improved fluidity and a Li+ diffusivity of 1.26 × 10−12 m2/s at 0 °C (xLi = 0.20) with a Li+ transference of 0.16. Improved transport properties translated to a higher capacity of the TTE/IL electrolyte in a Li||LiFePO4 half-cell with 95mAh/g at 0.1C, compared to the IL electrolyte without TTE (60 mAh/g). This study demonstrates the tunability of solvation and transport properties in IL electrolytes by asymmetric fluorinated anions and hydrofluoroether co-solvents for low temperature Li-ion batteries.
科研通智能强力驱动
Strongly Powered by AbleSci AI