skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Substituent-Stabilized Organic Dianions in the Gas Phase and Their Potential Use as Electrolytes in Lithium-Ion Batteries

Authors:
 [1];  [2];  [2]
  1. Department of Physics, School of Science, Beijing Jiaotong University, Beijing 100044 China, Department of Physics, Virginia Commonwealth University, Richmond Virginia 23284 USA
  2. Department of Physics, Virginia Commonwealth University, Richmond Virginia 23284 USA
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1401681
Grant/Contract Number:
AC02-05CH11231
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
ChemPhysChem
Additional Journal Information:
Journal Volume: 17; Journal Issue: 19; Related Information: CHORUS Timestamp: 2017-10-20 17:30:47; Journal ID: ISSN 1439-4235
Publisher:
Wiley Blackwell (John Wiley & Sons)
Country of Publication:
Germany
Language:
English

Citation Formats

Zhao, Hongmin, Zhou, Jian, and Jena, Puru. Substituent-Stabilized Organic Dianions in the Gas Phase and Their Potential Use as Electrolytes in Lithium-Ion Batteries. Germany: N. p., 2016. Web. doi:10.1002/cphc.201600467.
Zhao, Hongmin, Zhou, Jian, & Jena, Puru. Substituent-Stabilized Organic Dianions in the Gas Phase and Their Potential Use as Electrolytes in Lithium-Ion Batteries. Germany. doi:10.1002/cphc.201600467.
Zhao, Hongmin, Zhou, Jian, and Jena, Puru. 2016. "Substituent-Stabilized Organic Dianions in the Gas Phase and Their Potential Use as Electrolytes in Lithium-Ion Batteries". Germany. doi:10.1002/cphc.201600467.
@article{osti_1401681,
title = {Substituent-Stabilized Organic Dianions in the Gas Phase and Their Potential Use as Electrolytes in Lithium-Ion Batteries},
author = {Zhao, Hongmin and Zhou, Jian and Jena, Puru},
abstractNote = {},
doi = {10.1002/cphc.201600467},
journal = {ChemPhysChem},
number = 19,
volume = 17,
place = {Germany},
year = 2016,
month = 7
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1002/cphc.201600467

Save / Share:
  • The effects of lithium imide and lithium orthoborate dual-salt electrolytes of different salt chemistries in carbonate solvents on the cycling stability of lithium (Li) metal batteries are systematically and comparatively investigated. Two imide salts (LiTFSI and LiFSI) and two orthoborate salts (LiBOB and LiDFOB) are chosen for this study and compared with the conventional LiPF6 salt. Density functional theory calculations indicate that the chemical and electrochemical stabilities follow the order of LiTFSI-LiBOB > LiTFSI-LiDFOB > LiFSI-LiDFOB > LiFSI-LiBOB. The experimental cycling stability of the Li metal batteries with the electrolytes follows the order as LiTFSI-LiBOB > LiTFSI-LiDFOB > LiFSI-LiDFOB >more » LiPF6 > LiFSI-LiBOB, which is in well accordance with the calculation results. The LiTFSI-LiBOB can effectively protect the Al substrate and form a more robust surface film on Li metal anode, while the LiFSI-LiBOB results in serious corrosion to the stainless steel cell case and a thicker and looser surface film on Li anode. In conclusion, the key findings of this work emphasize that the salt chemistry is critically important for enhancing the interfacial stability of Li metal anode and should be carefully manipulated in the development of high performance Li metal batteries.« less
  • In this study, the effects of lithium imide and lithium orthoborate dual-salt electrolytes of different salt chemistries in carbonate solvents on the cycling stability of lithium (Li) metal batteries are systematically and comparatively investigated. Two imide salts (LiTFSI and LiFSI) and two orthoborate salts (LiBOB and LiDFOB) are chosen for this study and compared with the conventional LiPF6 salt. Density functional theory calculations indicate that the chemical and electrochemical stabilities follow the order of LiTFSI-LiBOB > LiTFSI-LiDFOB > LiFSI-LiDFOB > LiFSI-LiBOB. The experimental cycling stability of the Li metal batteries with the electrolytes follows the order as LiTFSI-LiBOB > LiTFSI-LiDFOBmore » > LiFSI-LiDFOB > LiPF6 > LiFSI-LiBOB, which is in well accordance with the calculation results. The LiTFSI-LiBOB can effectively protect the Al substrate and form a more robust surface film on Li metal anode, while the LiFSI-LiBOB results in serious corrosion to the stainless steel cell case and a thicker and looser surface film on Li anode. In conclusion, the key findings of this work emphasize that the salt chemistry is critically important for enhancing the interfacial stability of Li metal anode and should be carefully manipulated in the development of high performance Li metal batteries.« less
  • A bicyclic imidazolium ionic liquids, 1-ethyl-2,3-trimethyleneimidazolium bis(tri fluoromethane sulfonyl)imide ([ETMIm][TFSI]), and reference imidazolium compounds, 1-ethyl-3-methylimidazolium bis(trifluoromethane sulfonyl)imide ([EMIm][TFSI]) and 1, 2-dimethyl-3-butylimidazolium bis(trifluoromethane sulfonyl)imide ([DMBIm][TFSI]), were synthesized and investigated as solvents for lithium ion batteries. Although the alkylation at the C-2 position of the imidazolium ring does not affect the thermal stability of the ionic liquids, with or without the presence of 0.5 molar lithium bis(trifluoromethane sulfonyl)imide (LiTFSI), the stereochemical structure of the molecules has shown profound influences on the electrochemical properties of the corresponding ionic liquids. [ETMIm][TFSI] shows better reduction stability than do [EMIm][TFSI] and [DMBIm][TFSI], as confirmed by bothmore » linear sweep voltammery (LSV) and theoretical calculation. The Li||Li cell impedance of 0.5M LiTFSI/[ETMIm][TFSI] is stabilized, whereas that of 0.5M LiTFSI/[DMBIm][TFSI] is still fluctuating after 20 hours, indicating a relatively stable solid electrolyte interphase (SEI) is formed in the former. Furthermore, the Li||graphite half-cell based on 0.5M LiTFSI/[BTMIm][TFSI] exhibits reversible capacity of 250mAh g-1 and 70mAh g-1 at 25 C, which increases to 330 mAh g-1 and 250 mAh g-1 at 50 C, under the current rate of C/20 and C/10, respectively. For comparison, the Li||graphite half-cell based on 0.5M LiTFSI/[DMBIm][TFSI] exhibits poor capacity retention under the same current rate at both temperatures.« less
  • Rechargeable lithium (Li) metal batteries with conventional LiPF6-carbonate electrolytes have been reported to fail quickly at charging current densities of about 1.0 mA cm-2 and above. In this work, we demonstrate the rapid charging capability of the Li||LiNi0.8Co0.15Al0.05O2 (NCA) cells enabled by a dual-salt electrolyte of LiTFSI-LiBOB in a carbonate solvent mixture. It is found that the thickness of solid electrolyte interphase (SEI) layer on Li metal anode largely increases with increasing charging current density. However, the cells using the LiTFSI-LiBOB dual-salt electrolyte significantly outperforms those using the LiPF6 electrolyte at high charging current densities. At the charging current densitymore » of 1.50 mA cm-2, the Li||NCA cells with the dual-salt electrolyte can still deliver a discharge capacity of 131 mAh g-1 and a capacity retention of 80% after 100 cycles, while those with the LiPF6 electrolyte start to show fast capacity fading after the 30th cycle and only exhibit a low capacity of 25 mAh g-1 and a low retention of 15% after 100 cycles. The reasons for the good chargeability and cycling stability of the cells using LiTFSI-LiBOB dual-salt electrolyte can be attributed to the good film-formation ability of the electrolyte on lithium metal anode and the highly conductive nature of the sulfur-rich interphase layer.« less