Nanoscale. 2015 May 07;7(17):8093-100. doi: 10.1039/c5nr00885a.

High-performance graphene/sulphur electrodes for flexible Li-ion batteries using the low-temperature spraying method.

Nanoscale

Pushpendra Kumar, Feng-Yu Wu, Lung-Hao Hu, Syed Ali Abbas, Jun Ming, Chia-Nan Lin, Jason Fang, Chih-Wei Chu, Lain-Jong Li

PMID: 25873204 DOI: 10.1039/c5nr00885a

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 (∼70% capacity retention after 250 cycles), good coulombic efficiency (∼98%) and high capacity (∼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.

Publication Types

• Journal Article
• Research Support, Non-U.S. Gov't