Title: High-performance graphene/sulphur electrodes for flexible Li-ion batteries using the low-temperature spraying method
Authors: Kumar, Pushpendra
Wu, Feng-Yu
Hu, Lung-Hao
Abbas, Syed Ali
Ming, Jun
Lin, Chia-Nan
Fang, Jason
Chu, Chih-Wei
Li, Lain-Jong
Department of Electrophysics
Issue Date: 1-Jan-2015
Abstract: Elementary sulphur (S) has been shown to be an excellent cathode material in energy storage devices such as Li-S batteries owing to its very high capacity. The major challenges associated with the sulphur cathodes are structural degradation, poor cycling performance and instability of the solid-electrolyte interphase caused by the dissolution of polysulfides during cycling. Tremendous efforts made by others have demonstrated that encapsulation of S materials improves their cycling performance. To make this approach practical for large scale applications, the use of low-cost technology and materials has become a crucial and new focus of S-based Li-ion batteries. Herein, we propose to use a low temperature spraying process to fabricate graphene/S electrode material, where the ink is composed of graphene flakes and the micron-sized S particles prepared by grinding of low-cost S powders. The S particles are found to be well hosted by highly conductive graphene flakes and consequently superior cyclability (similar to 70% capacity retention after 250 cycles), good coulombic efficiency (similar to 98%) and high capacity (similar to 1500 mA h g(-1)) are obtained. The proposed approach does not require high temperature annealing or baking; hence, another great advantage is to make flexible Li-ion batteries. We have also demonstrated two types of flexible batteries using sprayed graphene/S electrodes.
URI: http://dx.doi.org/10.1039/c5nr00885a
ISSN: 2040-3364
DOI: 10.1039/c5nr00885a
Issue: 17
Begin Page: 8093
End Page: 8100
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