Initiating a Reversible Aqueous Zn/Sulfur Battery through a “Liquid Film”

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

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Detail(s)

Original languageEnglish
Article number2003070
Journal / PublicationAdvanced Materials
Volume32
Issue number32
Online published28 Jun 2020
Publication statusPublished - 13 Aug 2020

Abstract

Sulfur cathodes have been under intensive study in various systems, such as Li/S, Na/S, Mg/S, and Al/S batteries. However, to date, Zn/S chemistry has never been reported. The first reliable aqueous Zn/polysulfide system activated by a “liquid film” comprising 4-(3-butyl-1-imidazolio)-1-butanesulfoni ionic liquid (IL) encapsulated within PEDOT:PSS. CF3SO3 anions in the IL operating as Zn2+-transfer channels is reported. Moreover, the PEDOT:PSS network retains the IL, which renders Zn2+-transfer channels and a polysulfide cathode with enhanced structural stability. The Zn/polysulfide system delivers extraordinary capacity of 1148 mAh g−1 and overwhelming energy density of 724.7 Wh kg−1cathode at 0.3 Ag−1. During the discharging phase, S62− is dominantly reduced by Zn to S2− (S6 → S2−). During the charging phase, these short chains are oxidized to form long-chain ZnxLiyS3-6. A further optimized high-concentrated salt electrolyte is used to improve the reversibility of the battery, demonstrating an extended lifetime over 1600 cycles at 1 Ag−1 with a capacity retention of 204 mAh g−1. This facile approach and the superior performance of the developed aqueous Zn/S chemistry provide a new platform for sulfur-based battery and potentially solve the problems of other metal/sulfur batteries.

Research Area(s)

  • aqueous batteries, ionic liquid films, sulfur cathodes, zinc ion batteries, zinc/sulfur batteries