A spheres-in-tube carbonaceous nanostructure for high-capacity and high-rate lithium–sulfur batteries

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Vol. 6; no. 30; pp. 14885 - 14893
• Main Authors: Ge, Yuanhang, Chen, Ze, Ye, Sunjie, Zhu, Zhifeng, Tu, Yingfeng, Yang, Xiaoming
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 2018
• Subjects: Batteries; Discharge capacity; Electrical conductivity; Electrical resistivity; Lithium; Lithium batteries; Porosity; Specific capacity; Sulfur
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/C8TA05041D

The uses of sulfur, which has a high theoretical specific capacity of 1675 mA h g −1 , as a commercial cathode for lithium batteries have been substantially hindered by the insulating nature of sulfur and the dissolution of intermediate polysulfides (Li 2 S x , 4 < x ≤ 8) into the electrolyte. In this work, a spheres-in-tube carbonaceous nanoarchitecture has been successfully engineered as an effective sulfur host, by encapsulating heteroatom-doped hollow carbon spheres into an intact carbonaceous nanotube (I-HCSs@CT). The structural features including hierarchical porosity and the intact nature of the CT wall and HCS framework have cooperatively endowed I-HCSs@CT with outstanding capability of host loading, good electrical conductivity, a high utilization rate and excellent stability of sulfur. As a result, our sulfur/carbon composites deliver a large discharge capacity of 1426 mA h g −1 at 0.1C with a high sulfur loading of 72.1 wt%. The obtained electrode demonstrates superior high-rate cycling performance, with a high specific capacity of 746 mA h g −1 at 0.5C being retained after 500 cycles.