Solvation-property relationship of lithium-sulphur battery electrolytes

Sang Cheol Kim; Xin Gao; Sheng-Lun Liao; Hance Su; Yuelang Chen; Wenbo Zhang; Louisa C Greenburg; Jou-An Pan; Xueli Zheng; Yusheng Ye; Mun Sek Kim; Philaphon Sayavong; Aaron Brest; Jian Qin; Zhenan Bao; Yi Cui

doi:10.1038/s41467-023-44527-x

Solvation-property relationship of lithium-sulphur battery electrolytes

Nat Commun. 2024 Feb 10;15(1):1268. doi: 10.1038/s41467-023-44527-x.

Authors

Sang Cheol Kim^#¹, Xin Gao^#¹, Sheng-Lun Liao², Hance Su¹, Yuelang Chen³, Wenbo Zhang¹, Louisa C Greenburg¹, Jou-An Pan¹, Xueli Zheng¹, Yusheng Ye¹, Mun Sek Kim², Philaphon Sayavong³, Aaron Brest¹, Jian Qin⁴, Zhenan Bao⁵, Yi Cui^{6

7

8}

Affiliations

¹ Department of Materials Science and Engineering, Stanford University, Stanford, CA, 94305, USA.
² Department of Chemical Engineering, Stanford University, Stanford, CA, 94305, USA.
³ Department of Chemistry, Stanford University, Stanford, CA, 94305, USA.
⁴ Department of Chemical Engineering, Stanford University, Stanford, CA, 94305, USA. jianq@stanford.edu.
⁵ Department of Chemical Engineering, Stanford University, Stanford, CA, 94305, USA. zbao@stanford.edu.
⁶ Department of Materials Science and Engineering, Stanford University, Stanford, CA, 94305, USA. yicui@stanford.edu.
⁷ Department of Energy Science and Engineering, Stanford University, Stanford, CA, 94305, USA. yicui@stanford.edu.
⁸ Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA. yicui@stanford.edu.

^# Contributed equally.

Abstract

The Li-S battery is a promising next-generation battery chemistry that offers high energy density and low cost. The Li-S battery has a unique chemistry with intermediate sulphur species readily solvated in electrolytes, and understanding their implications is important from both practical and fundamental perspectives. In this study, we utilise the solvation free energy of electrolytes as a metric to formulate solvation-property relationships in various electrolytes and investigate their impact on the solvated lithium polysulphides. We find that solvation free energy influences Li-S battery voltage profile, lithium polysulphide solubility, Li-S battery cyclability and the Li metal anode; weaker solvation leads to lower 1^st plateau voltage, higher 2^nd plateau voltage, lower lithium polysulphide solubility, and superior cyclability of Li-S full cells and Li metal anodes. We believe that relationships delineated in this study can guide the design of high-performance electrolytes for Li-S batteries.