Abstract
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.
Original language | British English |
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Pages (from-to) | 349-359 |
Number of pages | 11 |
Journal | Journal of Solid State Electrochemistry |
Volume | 21 |
Issue number | 2 |
DOIs | |
State | Published - 1 Feb 2017 |
Keywords
- Hierarchical
- Li-S battery
- S@CuS@CNT
- Supercapacitor
- Synergistic