Copper sulfide nanoneedles on CNT backbone composite electrodes for high-performance supercapacitors and Li-S batteries

详细信息    查看全文

• 作者：Xiaoyi Hou ; Xianming Liu ; Yang Lu ; Jinbing Cheng&#8230
• 关键词：S@CuS@CNT ; Hierarchical ; Synergistic ; Supercapacitor ; Li ; S battery
• 刊名：Journal of Solid State Electrochemistry
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：21
• 期：2
• 页码：349-359
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Physical Chemistry; Electrochemistry; Energy Storage; Characterization and Evaluation of Materials; Analytical Chemistry; Condensed Matter Physics;
• 出版者：Springer Berlin Heidelberg
• ISSN：1433-0768
• 卷排序：21

文摘

Hierarchical-structured copper sulfide nanoneedles were grown on multi-walled carbon nanotube backbone (denoted as CuS@CNT) as electrodes for supercapacitors via a facile template-based hydrothermal conversion approach and further by simply impregnating sulfur into CuS@CNT (S@CuS@CNT) as electrodes for Li-S batteries. The electrochemical measurements showed that the resultant CuS@CNT composite electrodes deliver outstanding electrochemical performance with a specific capacitance up to 566.4 F g−1 and cyclic stability of 94.5 % of its initial capacitance after 5000 cycles at a current density of 1 A g−1. A synergistic effect arising from the unique hierarchical structure was responsible for the electrode performance, including a large surface area of 49.3 m2 g−1 and active CuS ultrafine nanoneedles firmly bonded to the highly conductive carbon nanotube (CNT) backbone. When used as an electrode material for Li-S batteries, the S@CuS@CNT (S content 59 wt%) exhibited satisfying electrochemical performance. The S@CuS@CNT electrode showed that coulombic efficiency was close to 100 % and capacity maintained more than 500 mA h g−1 with progressive cycling up to more than 100 cycles even at a high current density. This strategy of stabilizing S with a small amount of copper sulfide nanoneedles can be a very promising method to prepare free-standing cathode material for high-performance Li-S batteries. The fabrication strategy presented here is low cost, facile, and scalable, which can be considered as a promising material for large-scale energy storage device. In particular, the use of CNT as backbone for the growth of active materials presents many potential merits owing to its lightweight, biodegradable, and stretchable characteristics.