Boosting the anchoring and catalytic capability of MoSfor high-loading lithium sulfur batteries

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

12 Scopus Citations
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Detail(s)

Original languageEnglish
Pages (from-to)17646-17656
Journal / PublicationJournal of Materials Chemistry A
Volume8
Issue number34
Online published29 Jul 2020
Publication statusPublished - 14 Sep 2020
Externally publishedYes

Abstract

A high sulfur loading and low electrolyte/sulfur ratio are considered prerequisites for practical high-energy lithium sulfur batteries (LSBs); however, shuttling and the sluggish conversion of flooded polysulfides make it challenging to achieve the full utilization of active materials with an extended cyclic life. Herein, we explore 1T MoSnanodots as powerful electrocatalyst to overcome this issue. Electrochemical and synchrotron in situ X-ray diffraction characterizations revealed that 1T MoSnanodots with numerous active sites are favored to trap and propel the redox reactions for polysulfides. First-principle calculations indicated that the surface and Mo-terminated edges of 1T MoSprovide stronger anchor sites for Li2S, a lower Li-S decomposition barrier, and faster Li ion migration than those for the 2H phase, which suggest the unique catalytic property for edge-rich 1T MoSnanodots in LSBs. In the presence of a small amount of 1T MoSnanodots, porous carbon/Li2Scathodes exhibited remarkable electrochemical performance retaining a capacity of 9.3 mA h cm−2 over 300 cycles under high sulfur loading of 12.9 mg cm−2 and a low electrolyte/sulfur ratio of 4.6 μL mg−1, which rivals the performance of the state-of-the-art LSBs. Our combined experimental and theoretical analyses rationalized the use of nanodot catalysts in high energy rechargeable batteries.