Electrolyte Stability and Discharge Products of an Ionic-Liquid-Based Li–O2 Battery Revealed by Soft X-Ray Emission Spectroscopy

Léon, Aline; Fiedler, Andy; Blum, Monika; Yang, Wanli; Bär, Marcus; Scheiba, Frieder; Ehrenberg, Helmut; Heske, Clemens; Weinhardt, Lothar

doi:10.1021/acs.jpcc.9b08777

Title: Electrolyte Stability and Discharge Products of an Ionic-Liquid-Based Li–O₂ Battery Revealed by Soft X-Ray Emission Spectroscopy

Full Record
Other Related Research

Abstract

Here, we explore the electrolyte stability and discharge products of an ionic-liquid-based Li–O₂ battery through soft X-ray emission spectroscopy (XES) experiments, which offer unique site specificity for detecting subtle changes in the local nitrogen and oxygen environment. We benchmark the valence electronic structures of the molecules composing the electrolyte, namely the solvent PP13(TFSI), the salt LiTFSI, and the PP13 cation. Then, the transformation of the electrolyte is shown using cathodes stopped at different discharge and charge stages. We provide experimental evidence that the nitrogen site of the salt is unstable during electrochemical operation. The chemical environment of the nitrogen atoms is gradually changed during the electrochemical cycle, indicating the breaking of S–N bonds. The ionic liquid solvent remains mostly as an ion pair, but some decomposition into PP13 cations and TFSI anions cannot be ruled out. These findings and detailed analysis also show that the discharge products in our cell consist of lithium peroxide with some amount of hydroxide; however, no carbonate is observed.

Authors:

^[1]; Fiedler, Andy ^[1]; Blum, Monika ^[2];

^[3];

^[4];

^[1];

^[1]; Heske, Clemens ^[5];

^[5]

Karlsruhe Inst. of Technology (KIT) (Germany)
Univ. of Nevada, Las Vegas, NV (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source (ALS)
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source (ALS)
Helmholtz-Zentrum Berlin (HZB), (Germany). German Research Centre for Materials and Energy; Helmholtz-Inst. Erlangen-Nürnberg for Renewable Energy (HI ERN), Berlin (Germany); Univ. of Erlangen-Nuremberg (Germany)
Karlsruhe Inst. of Technology (KIT) (Germany); Univ. of Nevada, Las Vegas, NV (United States)

Publication Date:: Thu Nov 21 00:00:00 EST 2019

Research Org.:: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

Sponsoring Org.:: USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:: 1594943

Grant/Contract Number:: AC02-05CH11231

Resource Type:: Accepted Manuscript

Journal Name:: Journal of Physical Chemistry. C

Additional Journal Information:: Journal Volume: 123; Journal Issue: 51; Journal ID: ISSN 1932-7447

Publisher:: American Chemical Society

Country of Publication:: United States

Language:: English

Subject:: 25 ENERGY STORAGE; Salts; Electrodes; Solvents; Electrolytes; Lithium

Citation Formats


                    Léon, Aline, Fiedler, Andy, Blum, Monika, Yang, Wanli, Bär, Marcus, Scheiba, Frieder, Ehrenberg, Helmut, Heske, Clemens, and Weinhardt, Lothar. Electrolyte Stability and Discharge Products of an Ionic-Liquid-Based Li–O2 Battery Revealed by Soft X-Ray Emission Spectroscopy.  United States: N. p., 2019. 
Web.  doi:10.1021/acs.jpcc.9b08777.

Copy to clipboard


                    Léon, Aline, Fiedler, Andy, Blum, Monika, Yang, Wanli, Bär, Marcus, Scheiba, Frieder, Ehrenberg, Helmut, Heske, Clemens, & Weinhardt, Lothar. Electrolyte Stability and Discharge Products of an Ionic-Liquid-Based Li–O2 Battery Revealed by Soft X-Ray Emission Spectroscopy.  United States.  https://doi.org/10.1021/acs.jpcc.9b08777

Copy to clipboard


                    Léon, Aline, Fiedler, Andy, Blum, Monika, Yang, Wanli, Bär, Marcus, Scheiba, Frieder, Ehrenberg, Helmut, Heske, Clemens, and Weinhardt, Lothar. Thu .  
"Electrolyte Stability and Discharge Products of an Ionic-Liquid-Based Li–O2 Battery Revealed by Soft X-Ray Emission Spectroscopy".  United States.  https://doi.org/10.1021/acs.jpcc.9b08777.  https://www.osti.gov/servlets/purl/1594943.

Copy to clipboard


                    
@article{osti_1594943,

  title        = {Electrolyte Stability and Discharge Products of an Ionic-Liquid-Based Li–O2 Battery Revealed by Soft X-Ray Emission Spectroscopy},

  author       = {Léon, Aline and Fiedler, Andy and Blum, Monika and Yang, Wanli and Bär, Marcus and Scheiba, Frieder and Ehrenberg, Helmut and Heske, Clemens and Weinhardt, Lothar},

  abstractNote = {Here, we explore the electrolyte stability and discharge products of an ionic-liquid-based Li–O2 battery through soft X-ray emission spectroscopy (XES) experiments, which offer unique site specificity for detecting subtle changes in the local nitrogen and oxygen environment. We benchmark the valence electronic structures of the molecules composing the electrolyte, namely the solvent PP13(TFSI), the salt LiTFSI, and the PP13 cation. Then, the transformation of the electrolyte is shown using cathodes stopped at different discharge and charge stages. We provide experimental evidence that the nitrogen site of the salt is unstable during electrochemical operation. The chemical environment of the nitrogen atoms is gradually changed during the electrochemical cycle, indicating the breaking of S–N bonds. The ionic liquid solvent remains mostly as an ion pair, but some decomposition into PP13 cations and TFSI anions cannot be ruled out. These findings and detailed analysis also show that the discharge products in our cell consist of lithium peroxide with some amount of hydroxide; however, no carbonate is observed.},

  doi          = {10.1021/acs.jpcc.9b08777},

  journal      = {Journal of Physical Chemistry. C},

  number       = 51,

  volume       = 123,

  place        = {United States},

  year         = {Thu Nov 21 00:00:00 EST 2019},

  month        = {Thu Nov 21 00:00:00 EST 2019}

}

Copy to clipboard

Journal Article:

Free Publicly Available Full Text

Accepted Manuscript (DOE)

Publisher's Version of Record

https://doi.org/10.1021/acs.jpcc.9b08777

Other availability

Search WorldCat to find libraries that may hold this journal

Citation Metrics:

Cited by: 3 works

Citation information provided by
Web of Science

Save / Share:

Export Metadata

Save to My Library

Similar Records in DOE PAGES and OSTI.GOV collections:

Bicyclic imidazolium ionic liquids as potential electrolytes for rechargeable lithium ion batteries

Journal Article Liao, Chen ; Shao, Nan ; Bell, Jason R ; ... - Journal of Power Sources

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 »« less
Revealing the Correlation between the Solvation Structures and the Transport Properties of Water-in-Salt Electrolytes

Journal Article Liu, Xinyi ; Lee, Shao-Chun ; Seifert, Soenke ; ... - Chemistry of Materials

Water-in-salt (WIS) electrolytes containing 21 m lithium bis(trifluoromethane sulfonyl)imide (LiTFSI) have been considered as a safe and environment-friendly alternative to common organic electrolytes used in lithium-ion batteries. However, the relation between the solvation structures and transport properties of these materials remains elusive. Here, for this paper, we performed small-angle X-ray scattering (SAXS), small-angle neutron scattering (SANS), and X-ray pair distribution function (PDF) measurements of LiTFSI aqueous solutions at a wide range of concentrations. Combined with molecular dynamics simulations, the detailed solvation structures from long to short length scale were resolved. We found that the TFSI– solvation structures consist of TFSI–more »« less
https://doi.org/10.1021/acs.chemmater.2c03654

Full Text Available
Stabilization of Li Metal Anode in DMSO-Based Electrolytes via Optimization of Salt-Solvent Coordination for Li-O ₂ Batteries

Journal Article Liu, Bin ; Xu, Wu ; Yan, Pengfei ; ... - Advanced Energy Materials

The conventional DMSO-based electrolyte (1 M lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) in DMSO) is unstable against the Li metal anode and therefore cannot be used directly in practical Li-O2 batteries. Here, we demonstrate that a highly concentrated electrolyte based on LiTFSI in DMSO (with a molar ratio of 1:3) can greatly improve the stability of the Li metal anode against DMSO and significantly improve the cycling stability of Li-O2 batteries. This highly concentrated electrolyte contains no free DMSO solvent molecules, but only complexes of (TFSI–)a-Li+-(DMSO)b (where a + b = 4), and thus enhances their stability with Li metal anodes. In addition,more »« less
https://doi.org/10.1002/aenm.201602605
Stabilization of Li Metal Anode in DMSO‐Based Electrolytes via Optimization of Salt–Solvent Coordination for Li–O ₂ Batteries

Journal Article Liu, Bin ; Xu, Wu ; Yan, Pengfei ; ... - Advanced Energy Materials

The conventional electrolyte of 1 m lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) in dimethyl sulfoxide (DMSO) is unstable against the Li metal anode and therefore cannot be used directly in practical Li–O ₂ batteries. Here, we demonstrate that a highly concentrated electrolyte based on LiTFSI in DMSO (with a molar ratio of 1:3) can greatly improve the stability of the Li metal anode against DMSO and significantly improve the cycling stability of Li–O ₂ batteries. This highly concentrated electrolyte contains no free DMSO solvent molecules, but only complexes of (TFSI ⁻ ) _a Li ⁺ (DMSO) _b (where a + b = 4),more »« less
Cited by 89
https://doi.org/10.1002/aenm.201602605
Modifying Li⁺ and Anion Diffusivities in Polyacetal Electrolytes: A Pulsed-Field-Gradient NMR Study of Ion Self-Diffusion

Journal Article Halat, David M. ; Snyder, Rachel L. ; Sundararaman, Siddharth ; ... - Chemistry of Materials

Polyacetal electrolytes have been demonstrated as promising alternatives to liquid electrolytes and poly(ethylene oxide) (PEO) for rechargeable lithium-ion batteries; however, the relationship between polymer structure and ion motion is difficult to characterize. Here, we study structure-property trends in ion diffusion with respect to polymer composition for a systematic series of five polyacetals with varying ratios of ethylene oxide (EO) to methylene oxide (MO) units, denoted as P(xEO-yMO), and PEO. We first use ⁷Li and ¹⁹F pulsed-field-gradient NMR spectroscopy to measure cation and anion self-diffusion, respectively, in polymer/lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt mixtures. At 90 °C, we observe modest changes in Li⁺more »« less
https://doi.org/10.1021/acs.chemmater.1c00339

Full Text Available

Similar Records

Title: Electrolyte Stability and Discharge Products of an Ionic-Liquid-Based Li–O2 Battery Revealed by Soft X-Ray Emission Spectroscopy

Abstract

Citation Formats

Title: Electrolyte Stability and Discharge Products of an Ionic-Liquid-Based Li–O₂ Battery Revealed by Soft X-Ray Emission Spectroscopy