Investigation of surface effects through the application of the functional binders in lithium sulfur batteries

Publication Type

Journal Article

Date Published

09/2015

Abstract

Sulfur species dissolution, precipitation and phase transformation during the charge and discharge process strongly affect the performance of lithium sulfur (Li–S) batteries. Interface properties between electrode and electrolyte play an important role in these batteries. In this work, four kinds of binders with different functionalities, which differs both in chemical and electrical properties, are employed to study how the interface properties affect the battery reaction mechanism. The phase transformation of sulfur species is studied in detail. Remarkable differences are observed among sulfur cathodes with different binders. More solid-phase sulfur species precipitation is observed with binders that have carbonyl functional groups, like poly(9, 9-dioctylfluorene-co-fluorenone-co-methylbenzoic ester) (PFM) and poly(vinylpyrrolidone) (PVP), in both fully charged and discharged states. Also, the improved conductivity from introducing conductive binders greatly promotes sulfur species precipitation. These findings suggest that the contributions from functional groups affinity and binder conductivity lead to more sulfur transformation into the solid phase, so the shuttle effect can be greatly reduced, and a better cell performance can be obtained.

Journal

Nano Energy

Volume

16

Year of Publication

2015
28

Pagination

28-37

ISBN Number

2211-2855
Research Areas