Nucleophilic substitution between polysulfides and binders unexpectedly stabilizing lithium sulfur battery

Publication Type

Journal Article

Date Published

01/2017

Abstract

Polysulfide shuttling has been the primary cause of failure in lithium-sulfur (Li-S) battery cycling. Here, we demonstrate an nucleophilic substitution reaction between polysulfides and binder functional groups can unexpectedly immobilizes the polysulfides. The substitution reaction is verified by UV–visible spectra and X-ray photoelectron spectra. The immobilization of polysulfide is in situ monitored by synchrotron based sulfur K-edge X-ray absorption spectra. The resulting electrodes exhibit initial capacity up to 20.4 mAh/cm2, corresponding to 1199.1 mAh/g based on a micron-sulfur mass loading of 17.0 mg/cm2. The micron size sulfur transformed into nano layer coating on the cathode binder during cycling. Directly usage of nano-size sulfur promotes higher capacity of 33.7 mAh/cm2, which is the highest areal capacity reported in Li-S battery. This enhance performance is due to the reduced shuttle effect by covalently binding of the polysulfide with the polymer binder.

Journal

Nano Energy

Volume

38

Year of Publication

2017

Short Title

Nano Energy

Refereed Designation

Refereed

Pagination

82 - 90

ISSN

22112855
Research Areas