Insight into the Solid Electrolyte Interphase Formation in Bis(fluorosulfonyl)Imide Based Ionic Liquid Electrolytes

Charl J. Jafta; Xiao Guang Sun; Hailong Lyu; Hao Chen; Bishnu P. Thapaliya; William T. Heller; Matthew J. Cuneo; Richard T. Mayes; Mariappan Parans Paranthaman; Sheng Dai; Craig A. Bridges

doi:10.1002/adfm.202008708

Insight into the Solid Electrolyte Interphase Formation in Bis(fluorosulfonyl)Imide Based Ionic Liquid Electrolytes

Charl J. Jafta, Xiao Guang Sun, Hailong Lyu, Hao Chen, Bishnu P. Thapaliya, William T. Heller, Matthew J. Cuneo, Richard T. Mayes, Mariappan Parans Paranthaman, Sheng Dai, Craig A. Bridges

Research output: Contribution to journal › Article › peer-review

39 Scopus citations

Abstract

The formation of the solid electrolyte interphase (SEI) in an ionic liquid electrolyte of 0.5 m lithium bis(fluorosulfonyl)imide (LiFSI) in 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide at high cell voltages (1.7–1.9 V) is investigated in ordered mesoporous carbon (OMC) based Li metal cells using an operando small-angle neutron scattering (SANS) technique coupled with electrochemical impedance spectroscopy and ex situ X-ray photoelectron spectroscopy (XPS). It is demonstrated that discharging the OMC Li metal cells to ≈2 V and holding the cell voltage constant induces a rapid current increase with time, confirming extensive reduction and SEI formation. XPS analysis reveals that LiF is formed at open cell voltage (OCV), which is attributed to the carbenes generated at the lithium negative electrode because of its reaction with EMIm cation diffusing to and initiating the reaction with FSI⁻ anions at the carbon positive electrode. It is confirmed that the chemical reaction at OCV and electrochemical reduction at high cell voltage of the FSI⁻ anion plays a protective role against EMIm cation co-intercalation into the carbon positive electrode during the initial discharge. Operando SANS studies also suggest that slight differences occur in the surface composition and reaction mechanism as a function of cell voltage.

Original language	English
Article number	2008708
Journal	Advanced Functional Materials
Volume	31
Issue number	23
DOIs	https://doi.org/10.1002/adfm.202008708
State	Published - Jun 2 2021

Funding

This work was supported by the United States Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. Research at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, United States Department of Energy. This manuscript was authored by UT-Battelle, LLC under Contract No. DEAC05-00OR22725 with the United States Department of Energy. This article has been contributed to by US Government contractors and their work is in the public domain in the USA. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan). This work was supported by the United States Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. Research at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, United States Department of Energy. This manuscript was authored by UT‐Battelle, LLC under Contract No. DEAC05‐00OR22725 with the United States Department of Energy. This article has been contributed to by US Government contractors and their work is in the public domain in the USA. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( http://energy.gov/downloads/doe‐public‐access‐plan ).

Funders	Funder number
DOE Public Access Plan
Scientific User Facilities Division
U.S. Department of Energy
Office of Science
Basic Energy Sciences	DEAC05‐00OR22725
Division of Materials Sciences and Engineering

Keywords

1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide
ionic liquids
lithium bis(fluorosulfonyl)imide
neutron scattering
operando characterization
solid electrolyte interphase

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

Access to Document

10.1002/adfm.202008708

Cite this

Jafta, C. J., Sun, X. G., Lyu, H., Chen, H., Thapaliya, B. P., Heller, W. T., Cuneo, M. J., Mayes, R. T., Paranthaman, M. P., Dai, S., & Bridges, C. A. (2021). Insight into the Solid Electrolyte Interphase Formation in Bis(fluorosulfonyl)Imide Based Ionic Liquid Electrolytes. Advanced Functional Materials, 31(23), Article 2008708. https://doi.org/10.1002/adfm.202008708

@article{f5e5b9e5a77847da8cfb060ea6e55ffd,

title = "Insight into the Solid Electrolyte Interphase Formation in Bis(fluorosulfonyl)Imide Based Ionic Liquid Electrolytes",

abstract = "The formation of the solid electrolyte interphase (SEI) in an ionic liquid electrolyte of 0.5 m lithium bis(fluorosulfonyl)imide (LiFSI) in 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide at high cell voltages (1.7–1.9 V) is investigated in ordered mesoporous carbon (OMC) based Li metal cells using an operando small-angle neutron scattering (SANS) technique coupled with electrochemical impedance spectroscopy and ex situ X-ray photoelectron spectroscopy (XPS). It is demonstrated that discharging the OMC Li metal cells to ≈2 V and holding the cell voltage constant induces a rapid current increase with time, confirming extensive reduction and SEI formation. XPS analysis reveals that LiF is formed at open cell voltage (OCV), which is attributed to the carbenes generated at the lithium negative electrode because of its reaction with EMIm cation diffusing to and initiating the reaction with FSI− anions at the carbon positive electrode. It is confirmed that the chemical reaction at OCV and electrochemical reduction at high cell voltage of the FSI− anion plays a protective role against EMIm cation co-intercalation into the carbon positive electrode during the initial discharge. Operando SANS studies also suggest that slight differences occur in the surface composition and reaction mechanism as a function of cell voltage.",

keywords = "1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide, ionic liquids, lithium bis(fluorosulfonyl)imide, neutron scattering, operando characterization, solid electrolyte interphase",

author = "Jafta, {Charl J.} and Sun, {Xiao Guang} and Hailong Lyu and Hao Chen and Thapaliya, {Bishnu P.} and Heller, {William T.} and Cuneo, {Matthew J.} and Mayes, {Richard T.} and Paranthaman, {Mariappan Parans} and Sheng Dai and Bridges, {Craig A.}",

note = "Publisher Copyright: {\textcopyright} 2021 Wiley-VCH GmbH",

year = "2021",

month = jun,

day = "2",

doi = "10.1002/adfm.202008708",

language = "English",

volume = "31",

journal = "Advanced Functional Materials",

issn = "1616-301X",

publisher = "wiley",

number = "23",

}

TY - JOUR

T1 - Insight into the Solid Electrolyte Interphase Formation in Bis(fluorosulfonyl)Imide Based Ionic Liquid Electrolytes

AU - Jafta, Charl J.

AU - Sun, Xiao Guang

AU - Lyu, Hailong

AU - Chen, Hao

AU - Thapaliya, Bishnu P.

AU - Heller, William T.

AU - Cuneo, Matthew J.

AU - Mayes, Richard T.

AU - Paranthaman, Mariappan Parans

AU - Dai, Sheng

AU - Bridges, Craig A.

PY - 2021/6/2

Y1 - 2021/6/2

N2 - The formation of the solid electrolyte interphase (SEI) in an ionic liquid electrolyte of 0.5 m lithium bis(fluorosulfonyl)imide (LiFSI) in 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide at high cell voltages (1.7–1.9 V) is investigated in ordered mesoporous carbon (OMC) based Li metal cells using an operando small-angle neutron scattering (SANS) technique coupled with electrochemical impedance spectroscopy and ex situ X-ray photoelectron spectroscopy (XPS). It is demonstrated that discharging the OMC Li metal cells to ≈2 V and holding the cell voltage constant induces a rapid current increase with time, confirming extensive reduction and SEI formation. XPS analysis reveals that LiF is formed at open cell voltage (OCV), which is attributed to the carbenes generated at the lithium negative electrode because of its reaction with EMIm cation diffusing to and initiating the reaction with FSI− anions at the carbon positive electrode. It is confirmed that the chemical reaction at OCV and electrochemical reduction at high cell voltage of the FSI− anion plays a protective role against EMIm cation co-intercalation into the carbon positive electrode during the initial discharge. Operando SANS studies also suggest that slight differences occur in the surface composition and reaction mechanism as a function of cell voltage.

AB - The formation of the solid electrolyte interphase (SEI) in an ionic liquid electrolyte of 0.5 m lithium bis(fluorosulfonyl)imide (LiFSI) in 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide at high cell voltages (1.7–1.9 V) is investigated in ordered mesoporous carbon (OMC) based Li metal cells using an operando small-angle neutron scattering (SANS) technique coupled with electrochemical impedance spectroscopy and ex situ X-ray photoelectron spectroscopy (XPS). It is demonstrated that discharging the OMC Li metal cells to ≈2 V and holding the cell voltage constant induces a rapid current increase with time, confirming extensive reduction and SEI formation. XPS analysis reveals that LiF is formed at open cell voltage (OCV), which is attributed to the carbenes generated at the lithium negative electrode because of its reaction with EMIm cation diffusing to and initiating the reaction with FSI− anions at the carbon positive electrode. It is confirmed that the chemical reaction at OCV and electrochemical reduction at high cell voltage of the FSI− anion plays a protective role against EMIm cation co-intercalation into the carbon positive electrode during the initial discharge. Operando SANS studies also suggest that slight differences occur in the surface composition and reaction mechanism as a function of cell voltage.

KW - 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide

KW - ionic liquids

KW - lithium bis(fluorosulfonyl)imide

KW - neutron scattering

KW - operando characterization

KW - solid electrolyte interphase

UR - http://www.scopus.com/inward/record.url?scp=85100896037&partnerID=8YFLogxK

U2 - 10.1002/adfm.202008708

DO - 10.1002/adfm.202008708

M3 - Article

AN - SCOPUS:85100896037

SN - 1616-301X

VL - 31

JO - Advanced Functional Materials

JF - Advanced Functional Materials

IS - 23

M1 - 2008708

ER -

Insight into the Solid Electrolyte Interphase Formation in Bis(fluorosulfonyl)Imide Based Ionic Liquid Electrolytes

Abstract

Funding

Keywords

UN SDGs

Access to Document

Other files and links

Fingerprint

Cite this