Investigation of surface effects through the application of the functional binders in lithium sulfur batteries. (September 2015)

• Record Type: Journal Article
• Authors: Ai, Guo; Dai, Yiling; Ye, Yifan; Mao, Wenfeng; Wang, Zhihui; Zhao, Hui; Chen, Yulin; Zhu, Junfa; Fu, Yanbao; Battaglia, Vincent; Guo, Jinghua; Srinivasan, Venkat; Liu, Gao
• Is Part Of: Nano energy. Volume 16(2015:Sep.)
• Page Start: 28
• Page End: 37
• Publication Date: 2015-09
• Subjects: Li–S batteries -- Conductive binder -- Surface effect -- Self-discharge -- Binding energy -- Cell failure; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2015.05.036
• Languages: English
• ISSNs: 2211-2855

Abstract

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. Graphical abstract: The functionalities of binders can help the retention and precipitation of sulfur species in Li–S batteries. Highlights: Cell with functional conductive binder (PFM) shows the best electrochemical performance. Binders with carbonyl groups can assist sulfur species precipitation. Conductive binders can provide large surface for sulfur species precipitation.