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Title: Multinuclear NMR Study of the Solid Electrolyte Interface Formed in Lithium Metal Batteries

Abstract

The composition of the solid electrolyte interphase (SEI) layers associated with a high performance Cu|Li cell using lithium bis(fluorosulfonyi)imide (LiFSI) in 1,2-dimethoxyethane (DME) as electrolyte is determined by a multinuclear (6Li, 19F, 13C and 1H) solid-state MAS NMR study at high magnetic field (850 MHz). This cell can be cycled at high rates (4 mA•cm-2) for more than 1000 cycles with no increase in the cell impedance at high Columbic efficiency (average of 98.4%) in a highly concentrated LiFSI-DME electrolyte (4 M). LiFSI, LiF, Li2O2 (and/or CH3OLi), LiOH, Li2S and Li2O are observed in the SEI and validated by comparing with the spectra acquired on standard compounds and literature reports. To gain further insight into the role of the solute and its concentration dependence on the formation of SEIs while keeping the solvent of DME unchanged, the SEIs from different concentrations of LiFSI-DME and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI)-DME electrolyte are also investigated. It is found that LiF, a lithiated compound with superior mechanical strength and good Li+ ionic conductivity, is observed in the concentrated 4.0 M LiFSI-DME and the 3.0 M LiTFSI-DME systems but not in the diluted 1.0 M LiFSI-DME system. Li2O exists in both low and high concentration ofmore » LiFSI-DME while no Li2O is observed in the LiTFSI system. Furthermore, the dead metallic Li is reduced in the 4 M LiFSI-DME system compared with that in the 1 M LiFSI-DME system. Quantitative 6Li MAS results indicate that the SEI associated with the 4 M LiFSI-DEME is denser or thicker than that of the 1 M LiFSI-DME and the 3 M LiTFSI-DME systems. These findings are likely the reasons for explaining the high electrochemical performance associated with the high concentration LiFSI-DME system.« less

Authors:
; ; ; ; ; ; ; ORCiD logo; ORCiD logo; ORCiD logo
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1364007
Report Number(s):
PNNL-SA-122289
Journal ID: ISSN 1944-8244; 48776; KC0208010
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: ACS Applied Materials and Interfaces; Journal Volume: 9; Journal Issue: 17
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 25 ENERGY STORAGE; Environmental Molecular Sciences Laboratory

Citation Formats

Wan, Chuan, Xu, Suochang, Hu, Mary Y., Cao, Ruiguo, Qian, Jiangfeng, Qin, Zhaohai, Liu, Jun, Mueller, Karl T., Zhang, Ji-Guang, and Hu, Jian Zhi. Multinuclear NMR Study of the Solid Electrolyte Interface Formed in Lithium Metal Batteries. United States: N. p., 2017. Web. doi:10.1021/acsami.6b15383.
Wan, Chuan, Xu, Suochang, Hu, Mary Y., Cao, Ruiguo, Qian, Jiangfeng, Qin, Zhaohai, Liu, Jun, Mueller, Karl T., Zhang, Ji-Guang, & Hu, Jian Zhi. Multinuclear NMR Study of the Solid Electrolyte Interface Formed in Lithium Metal Batteries. United States. doi:10.1021/acsami.6b15383.
Wan, Chuan, Xu, Suochang, Hu, Mary Y., Cao, Ruiguo, Qian, Jiangfeng, Qin, Zhaohai, Liu, Jun, Mueller, Karl T., Zhang, Ji-Guang, and Hu, Jian Zhi. Tue . "Multinuclear NMR Study of the Solid Electrolyte Interface Formed in Lithium Metal Batteries". United States. doi:10.1021/acsami.6b15383.
@article{osti_1364007,
title = {Multinuclear NMR Study of the Solid Electrolyte Interface Formed in Lithium Metal Batteries},
author = {Wan, Chuan and Xu, Suochang and Hu, Mary Y. and Cao, Ruiguo and Qian, Jiangfeng and Qin, Zhaohai and Liu, Jun and Mueller, Karl T. and Zhang, Ji-Guang and Hu, Jian Zhi},
abstractNote = {The composition of the solid electrolyte interphase (SEI) layers associated with a high performance Cu|Li cell using lithium bis(fluorosulfonyi)imide (LiFSI) in 1,2-dimethoxyethane (DME) as electrolyte is determined by a multinuclear (6Li, 19F, 13C and 1H) solid-state MAS NMR study at high magnetic field (850 MHz). This cell can be cycled at high rates (4 mA•cm-2) for more than 1000 cycles with no increase in the cell impedance at high Columbic efficiency (average of 98.4%) in a highly concentrated LiFSI-DME electrolyte (4 M). LiFSI, LiF, Li2O2 (and/or CH3OLi), LiOH, Li2S and Li2O are observed in the SEI and validated by comparing with the spectra acquired on standard compounds and literature reports. To gain further insight into the role of the solute and its concentration dependence on the formation of SEIs while keeping the solvent of DME unchanged, the SEIs from different concentrations of LiFSI-DME and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI)-DME electrolyte are also investigated. It is found that LiF, a lithiated compound with superior mechanical strength and good Li+ ionic conductivity, is observed in the concentrated 4.0 M LiFSI-DME and the 3.0 M LiTFSI-DME systems but not in the diluted 1.0 M LiFSI-DME system. Li2O exists in both low and high concentration of LiFSI-DME while no Li2O is observed in the LiTFSI system. Furthermore, the dead metallic Li is reduced in the 4 M LiFSI-DME system compared with that in the 1 M LiFSI-DME system. Quantitative 6Li MAS results indicate that the SEI associated with the 4 M LiFSI-DEME is denser or thicker than that of the 1 M LiFSI-DME and the 3 M LiTFSI-DME systems. These findings are likely the reasons for explaining the high electrochemical performance associated with the high concentration LiFSI-DME system.},
doi = {10.1021/acsami.6b15383},
journal = {ACS Applied Materials and Interfaces},
number = 17,
volume = 9,
place = {United States},
year = {Tue Apr 18 00:00:00 EDT 2017},
month = {Tue Apr 18 00:00:00 EDT 2017}
}
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