Natural abundance 17O, 6Li NMR and molecular modeling studies of the solvation structures of lithium bis(fluorosulfonyl)imide/1,2-dimethoxyethane liquid electrolytes

JOURNAL OF POWER SOURCES

卷:307

Article

Wan, Chuan^1,2  Hu, Mary Y.¹  Borodin, Oleg³  Qian, Jiangfeng¹  Qin, Zhaohai²  Zhang, Ji-Guang¹  Hu, Jian Zhi¹ 

[1] Pacific NW Natl Lab, JCESR, Richland, WA 99354 USA

[2] China Agr Univ, Coll Sci, Beijing 100193, Peoples R China

[3] US Army, Electrochem Branch, Sensor & Electron Devices Directorate, Res Lab, Adelphi, MD 20783 USA

关键词: Natural abundance O-17 and Li-6 NMR;    Molecular modeling studies;    Electrolytes;    Lithium bis(fluorosulfonyl)imide;    1,2-Dimethoxyethane;    Solvation structure;   

DOI  :  10.1016/j.jpowsour.2015.12.120

来源: Elsevier

【 摘 要 】

Natural abundance O-17 and Li-6 NMR experiments, quantum chemistry and molecular dynamics studies were employed to investigate the solvation structures of Li+ at various concentrations of LiFSI in DME electrolytes. It was found that the chemical shifts of both O-17 and Li-6 changed with the concentration of LiFSI, indicating the changes of solvation structures with concentration. For the quantum chemistry calculations, the coordinated cluster LiFSI(DME)(2) forms at first, and its relative ratio increases with increasing LiFSI concentration to 1 M. Then the solvation structure LiFSI(DME) become the dominant component. As a result, the coordination of forming contact ion pairs between Li+ and FSI- ion increases, but the association between Li+ and DME molecule decreases. Furthermore, at LiFSI concentration of 4 M the solvation structures associated with Li+(FSI-)(2)(DME), Li-2(+)(FSI-)(DME)(4) and (LiFSI)(2)(DME)(3) become the dominant components. For the molecular dynamics simulation, with increasing concentration, the association between DME and Li+ decreases, and the coordinated number of FSI- increases, which is in perfect accord with the DFT results. (C) 2015 Published by Elsevier B.V.

【 授权许可】

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