Highly stable lithium sulfur batteries enhanced by flocculation and solidification of soluble polysulfides in routine ether electrolyte

Rui Xu; Jiashuo Shao; Keke Gao; Yunxiang Chen; Jin Li; Yifei Liu; Xinghui Hou; Haipeng Ji; Shasha Yi; Liying Zhang; Chuntai Liu; Xiao Liang; Yanfeng Gao; Zongtao Zhang

doi:10.1016/j.jcis.2023.06.065

Highly stable lithium sulfur batteries enhanced by flocculation and solidification of soluble polysulfides in routine ether electrolyte

J Colloid Interface Sci. 2023 Nov:649:223-233. doi: 10.1016/j.jcis.2023.06.065. Epub 2023 Jun 16.

Authors

Rui Xu¹, Jiashuo Shao¹, Keke Gao¹, Yunxiang Chen², Jin Li¹, Yifei Liu¹, Xinghui Hou¹, Haipeng Ji¹, Shasha Yi¹, Liying Zhang¹, Chuntai Liu³, Xiao Liang⁴, Yanfeng Gao⁵, Zongtao Zhang⁶

Affiliations

¹ School of Materials Science and Engineering, Zhengzhou University, Kexue Ave 100, Zhengzhou 450001, China.
² School of Materials Science and Engineering, Zhengzhou University, Kexue Ave 100, Zhengzhou 450001, China. Electronic address: yxchen@zzu.edu.cn.
³ Key Laboratory of Materials Processing and Mold (Ministry of Education), National Engineering Research Center for Advanced Polymer Processing Technology, Zhengzhou University, Zhengzhou 450002, China.
⁴ School of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China.
⁵ School of Materials Science and Engineering, Shanghai University, Shangda Rd 99, Shanghai 200444, China.
⁶ School of Materials Science and Engineering, Zhengzhou University, Kexue Ave 100, Zhengzhou 450001, China. Electronic address: ztzhang@zzu.edu.cn.

PMID: 37348342
DOI: 10.1016/j.jcis.2023.06.065

Abstract

Lithium-sulfur batteries (LSBs) are among the most promising next-generation high energy density energy-storage systems. However, practical application has been hindered by fundamental problems, especially shuttling by the higher-order polysulfides (PSs) and slow redox kinetics. Herein, a novel electrolyte-based strategy is proposed by adding an ultrasmall amount of the low-cost and commercially available cationic antistatic agent octadecyl dimethyl hydroxyethyl quaternary ammonium nitrate (SN) into a routine ether electrolyte. Due to the strong cation-anion interaction and bridge-bonding with SN, rapid flocculation of the soluble polysulfide intermediates into solid-state polysulfide-SN sediments is found, which significantly inhibited the adverse shuttling effect. Moreover, a catalytic effect was also demonstrated for conversion of the polysulfide-SN intermediates, which enhanced the redox kinetics of Li-S batteries. Encouragingly, for cells with only 0.1 % added SN, an initial specific capacity of 783.6 mAh/g and a retained specific capacity of 565.7 mAh/g were found at 2C after 200 cycles, which corresponded to an ultralow capacity decay rate of only 0.014 % per cycle. This work may provide a simple and promising regulation strategy for preparing highly stable Li-S batteries.

Keywords: Cationic surfactant; Electrolyte additive; Lithium-sulfur battery; Polysulfide conversion; SN.