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

Title: Electrolyte Concentration Effect on Sulfur Utilization of Li-S Batteries

Abstract

Electrolyte is the critical component of the Li-S battery. Past studies have shed light on the behavior of the Li-S cells when the electrolyte salt concentration is increased to the solvent-in-salt regime and demonstrated tremendously improved cycle life. However, there is no systematic study on the Li-S cell when the electrolyte salt concentration is reduced from the standard 1.0M condition. This work investigates the lower salt concentration regime by doing a systematic study with the standard LiTFSI in DME:DOL combination, using sulfur electrodes with relatively high loading (> 6 mg cm-2). Although reducing the electrolyte salt concentration lowers the ionic conductivity, it is found that the sulfur utilization and rate capability of the Li-S cells benefits from this process. Similar observations are also found when LiTFSI is replaced with LiI and LiBr, which form less conductive electrolytes than LiTFSI at the same concentration levels. Data correlation indicates a stronger correlation between the Li-S cell’s rate-capability and the electrolyte conductivity than electrolyte viscosity. It is proposed in this work that free Li+ concentration, which is proportional to the electrolyte conductivity, is the real rate-capability determining parameter. Reducing the electrolyte salt concentration and replacing LiTFSI with less dissociable salts (LiI, LiBr) bothmore » will reduce the free Li+ in the electrolyte, which will allow a higher saturation point of Li2S2/Li2S. This probably will delay the insulating layer build-up on the cathode conductive network and improve the dissolved Li-polysulfide to Li2S2/Li2S conversion efficiency. Both impedance and cathode morphology support this theorem.« less

Authors:
 [1];  [1];  [1]; ORCiD logo [1]
  1. Brookhaven National Lab. (BNL), Upton, NY (United States)
Publication Date:
Research Org.:
Brookhaven National Lab. (BNL), Upton, NY (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1495320
Report Number(s):
BNL-211287-2019-JAAM
Journal ID: ISSN 0013-4651
Grant/Contract Number:  
SC0012704
Resource Type:
Accepted Manuscript
Journal Name:
Journal of the Electrochemical Society
Additional Journal Information:
Journal Volume: 166; Journal Issue: 2; Journal ID: ISSN 0013-4651
Publisher:
The Electrochemical Society
Country of Publication:
United States
Language:
English
Subject:
29 ENERGY PLANNING, POLICY AND ECONOMY; Batteries Lithium; Electrolyte Concentration; Li-S Batteries; Sulfur Utilization

Citation Formats

Sun, Ke, Li, Na, Su, Dong, and Gan, Hong. Electrolyte Concentration Effect on Sulfur Utilization of Li-S Batteries. United States: N. p., 2019. Web. doi:10.1149/2.0161902jes.
Sun, Ke, Li, Na, Su, Dong, & Gan, Hong. Electrolyte Concentration Effect on Sulfur Utilization of Li-S Batteries. United States. doi:10.1149/2.0161902jes.
Sun, Ke, Li, Na, Su, Dong, and Gan, Hong. Fri . "Electrolyte Concentration Effect on Sulfur Utilization of Li-S Batteries". United States. doi:10.1149/2.0161902jes. https://www.osti.gov/servlets/purl/1495320.
@article{osti_1495320,
title = {Electrolyte Concentration Effect on Sulfur Utilization of Li-S Batteries},
author = {Sun, Ke and Li, Na and Su, Dong and Gan, Hong},
abstractNote = {Electrolyte is the critical component of the Li-S battery. Past studies have shed light on the behavior of the Li-S cells when the electrolyte salt concentration is increased to the solvent-in-salt regime and demonstrated tremendously improved cycle life. However, there is no systematic study on the Li-S cell when the electrolyte salt concentration is reduced from the standard 1.0M condition. This work investigates the lower salt concentration regime by doing a systematic study with the standard LiTFSI in DME:DOL combination, using sulfur electrodes with relatively high loading (> 6 mg cm-2). Although reducing the electrolyte salt concentration lowers the ionic conductivity, it is found that the sulfur utilization and rate capability of the Li-S cells benefits from this process. Similar observations are also found when LiTFSI is replaced with LiI and LiBr, which form less conductive electrolytes than LiTFSI at the same concentration levels. Data correlation indicates a stronger correlation between the Li-S cell’s rate-capability and the electrolyte conductivity than electrolyte viscosity. It is proposed in this work that free Li+ concentration, which is proportional to the electrolyte conductivity, is the real rate-capability determining parameter. Reducing the electrolyte salt concentration and replacing LiTFSI with less dissociable salts (LiI, LiBr) both will reduce the free Li+ in the electrolyte, which will allow a higher saturation point of Li2S2/Li2S. This probably will delay the insulating layer build-up on the cathode conductive network and improve the dissolved Li-polysulfide to Li2S2/Li2S conversion efficiency. Both impedance and cathode morphology support this theorem.},
doi = {10.1149/2.0161902jes},
journal = {Journal of the Electrochemical Society},
number = 2,
volume = 166,
place = {United States},
year = {2019},
month = {1}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Save / Share:

Works referenced in this record:

Unique behaviour of nonsolvents for polysulphides in lithium–sulphur batteries
journal, January 2014

  • Cuisinier, M.; Cabelguen, P. -E.; Adams, B. D.
  • Energy Environ. Sci., Vol. 7, Issue 8
  • DOI: 10.1039/C4EE00372A

Predicting the composition and formation of solid products in lithium–sulfur batteries by using an experimental phase diagram
journal, January 2016

  • Dibden, J. W.; Smith, J. W.; Zhou, N.
  • Chemical Communications, Vol. 52, Issue 87
  • DOI: 10.1039/C6CC05881G

Lithium Iodide as a Promising Electrolyte Additive for Lithium-Sulfur Batteries: Mechanisms of Performance Enhancement
journal, November 2014


Rapidly falling costs of battery packs for electric vehicles
journal, March 2015


Liquid electrolyte lithium/sulfur battery: Fundamental chemistry, problems, and solutions
journal, June 2013


Long term stability of Li-S batteries using high concentration lithium nitrate electrolytes
journal, October 2017


Rechargeable Lithium–Sulfur Batteries
journal, July 2014

  • Manthiram, Arumugam; Fu, Yongzhu; Chung, Sheng-Heng
  • Chemical Reviews, Vol. 114, Issue 23
  • DOI: 10.1021/cr500062v

Radical or Not Radical: Revisiting Lithium-Sulfur Electrochemistry in Nonaqueous Electrolytes
journal, January 2015

  • Cuisinier, Marine; Hart, Connor; Balasubramanian, Mahalingam
  • Advanced Energy Materials, Vol. 5, Issue 16
  • DOI: 10.1002/aenm.201401801

A new ether-based electrolyte for lithium sulfur batteries using a S@pPAN cathode
journal, January 2018

  • Zhou, Jingjing; Guo, Yongsheng; Liang, Chengdu
  • Chemical Communications, Vol. 54, Issue 43
  • DOI: 10.1039/C8CC02552E

Electrochemical Impedance Spectroscopy Study of a Lithium/Sulfur Battery: Modeling and Analysis of Capacity Fading
journal, January 2013

  • Deng, Zhaofeng; Zhang, Zhian; Lai, Yanqing
  • Journal of The Electrochemical Society, Vol. 160, Issue 4
  • DOI: 10.1149/2.026304jes

A new class of Solvent-in-Salt electrolyte for high-energy rechargeable metallic lithium batteries
journal, February 2013

  • Suo, Liumin; Hu, Yong-Sheng; Li, Hong
  • Nature Communications, Vol. 4, Issue 1
  • DOI: 10.1038/ncomms2513

The irreversible momentum of clean energy
journal, January 2017


Understanding the Effect of a Fluorinated Ether on the Performance of Lithium–Sulfur Batteries
journal, April 2015

  • Azimi, Nasim; Xue, Zheng; Bloom, Ira
  • ACS Applied Materials & Interfaces, Vol. 7, Issue 17
  • DOI: 10.1021/acsami.5b01412

Li–O2 and Li–S batteries with high energy storage
journal, January 2012

  • Bruce, Peter G.; Freunberger, Stefan A.; Hardwick, Laurence J.
  • Nature Materials, Vol. 11, Issue 1, p. 19-29
  • DOI: 10.1038/nmat3191

Low Temperature Performance of Li/S Batteries
journal, January 2003

  • Mikhaylik, Yuriy V.; Akridge, James R.
  • Journal of The Electrochemical Society, Vol. 150, Issue 3
  • DOI: 10.1149/1.1545452

Effect of Electrolyte on High Sulfur Loading Li-S Batteries
journal, January 2018

  • Sun, Ke; Matarasso, Avi K.; Epler, Ruby M.
  • Journal of The Electrochemical Society, Vol. 165, Issue 2
  • DOI: 10.1149/2.0071803jes

Effects of Liquid Electrolytes on the Charge–Discharge Performance of Rechargeable Lithium/Sulfur Batteries: Electrochemical and in-Situ X-ray Absorption Spectroscopic Studies
journal, October 2011

  • Gao, Jie; Lowe, Michael A.; Kiya, Yasuyuki
  • The Journal of Physical Chemistry C, Vol. 115, Issue 50, p. 25132-25137
  • DOI: 10.1021/jp207714c

Elucidating the Solvation Structure and Dynamics of Lithium Polysulfides Resulting from Competitive Salt and Solvent Interactions
journal, April 2017


Direct Observation of Sulfur Radicals as Reaction Media in Lithium Sulfur Batteries
journal, December 2014

  • Wang, Qiang; Zheng, Jianming; Walter, Eric
  • Journal of The Electrochemical Society, Vol. 162, Issue 3
  • DOI: 10.1149/2.0851503jes

Sulfur Speciation in Li–S Batteries Determined by Operando X-ray Absorption Spectroscopy
journal, September 2013

  • Cuisinier, Marine; Cabelguen, Pierre-Etienne; Evers, Scott
  • The Journal of Physical Chemistry Letters, Vol. 4, Issue 19
  • DOI: 10.1021/jz401763d

Sparingly Solvating Electrolytes for High Energy Density Lithium–Sulfur Batteries
journal, August 2016


The Use of Redox Mediators for Enhancing Utilization of Li 2 S Cathodes for Advanced Li–S Battery Systems
journal, February 2014

  • Meini, Stefano; Elazari, Ran; Rosenman, Ariel
  • The Journal of Physical Chemistry Letters, Vol. 5, Issue 5
  • DOI: 10.1021/jz500222f