Sulfur/Polythiophene with a Core/Shell Structure: Synthesis and Electrochemical Properties of the Cathode for Rechargeable Lithium Batteries
Sulfur/Polythiophene with a Core/Shell Structure: Synthesis and Electrochemical Properties of the Cathode for Rechargeable Lithium Batteries
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具有核/壳结构的硫/聚噻吩：可充电锂电池正极的合成和电化学性能
DOI：
10.1021/jp1114724
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发表时间：
2011-04-07
影响因子：
3.7
通讯作者：
Zhao, Teng
中科院分区：
文献类型：
--
作者：
Wu, Feng;Chen, Junzheng;Zhao, Teng
以三氯甲烷为溶剂，噻吩为试剂，氯化铁为氧化剂，在0 ℃下通过原位化学氧化聚合法合成了具有核/壳结构的新型硫磺/聚噻吩复合材料。采用元素分析、红外光谱、X射线衍射、扫描电子显微镜、透射电子显微镜和电化学方法对不同比例的硫/聚噻吩复合材料进行了表征。由CV和EIS结果确定的复合材料的合适比例为71.9%硫和18.1%聚噻吩。导电聚噻吩作为导电添加剂和多孔吸附剂。将其均匀包覆在硫磺粉表面形成核/壳结构，有效提高了硫电池的电化学性能和循环寿命。活性材料的初始放电容量为1119.3mA·h·g（-1）硫，并且在80次循环后剩余容量为830.2mA·h·g（-1）硫。在从100至1600 mA g（-1）硫的速率测试之后，当电流密度返回到100 mA g（-1）硫时，电池在60次循环之后保持在811 mA h g（-1）硫。与纯硫电极相比，S-PTh核/壳电极在锂硫电池中的硫利用率、循环寿命和倍率性能显著改善。壳层的孔隙和厚度影响锂离子扩散通道的电池性能。
Novel sulfur/polythiopliene composites with core/shell structure composites were synthesized via an in situ chemical oxidative polymerization method with chloroform as a solvent, thiophene as a reagent, and iron chloride as an oxidant at 0 degrees C. Different ratios of the sulfur/polythiophene composites were characterized by elemental analysis, FTIR, XRD, SEM, TEM, and electrochemical methods. A suitable ratio for the composites was found to be 71.9% sulfur and 18.1% polythiophene as determined by CV and EIS results. Conductive polythiophene acts as a conducting additive and a porous adsorbing agent. It was uniformly coated onto the surface of the sulfur powder to form a core/shell structure, which effectively enhances the electrochemical performance and cycle life of the sulfur cells. The initial discharge capacity of the active material was 1119.3 mA h g(-1), sulfur and the remaining capacity was 830.2 mA h g(-1) sulfur after 80 cycles. After a rate test from 100 to 1600 mA g(-1) sulfur, the cell remained at 811 mA h g(-1) sulfur after 60 cycles when the current density returned to 100 mA g(-1) sulfur. The sulfur utilization, the cycle life, and the rate performance of the S-PTh core/shell electrode in a lithium-sulfur battery improved significantly compared to that of the pure sulfur electrode. The pore and thickness of the shell affected the battery performance of the lithium ion diffusion channels.