1. PEO-coated sulfur-carbon composite for high-performance lithium-sulfur batteries.
- Author
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Li, LinYan, Liu, Xiaoyan, Zhu, Kunlei, Tian, Jianhua, Liu, Xuesheng, Yang, Kai, and Shan, Zhongqiang
- Subjects
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POLYETHYLENE oxide , *LITHIUM sulfur batteries , *CHEMICAL synthesis , *ELECTROCHEMICAL analysis , *ELECTRIC conductivity - Abstract
Poly(ethylene oxide)-coated sulfur/carbon (S/C/PEO) composite with a high sulfur loading is prepared to improve the performance of lithium-sulfur batteries. By magnetic string, 3.7 wt% PEO is coated onto the surface of ball-milling obtained S/C composite, leading to synthesis of S/C/PEO composite containing 78 wt% S. It is confirmed from a series of measurements that PEO covers the S/C composite uniformly, and PEO coating is quite effective in stabilizing the electrochemical performance. When employed as cathode for lithium-sulfur batteries, S/C/PEO delivers an initial discharge capacity of 989.6 mAh g and remains 648.3 mAh g after 110 cycles at a discharge/charge rate of 1 C (based on sulfur weight). Meanwhile, the coulomb efficiency of S/C/PEO composite reaches to ~98 % during the latter 105 cycles. The improved electrochemical performance can be attributed to the formation of PEO coating layer which can keep a tight contact between carbon and sulfur and lead to improved conductivity. Moreover, the PEO coating can act as a flexible cushion to accommodate volume changes of sulfur cathode as well as a barrier to trap soluble polysulfide intermediates during the charge-discharge processes. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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