Copolymerization of Polythiophene and Sulfur To Improve the Electrochemical Performance in Lithium–Sulfur Batteries
Copolymerization of Polythiophene and Sulfur To Improve the Electrochemical Performance in Lithium–Sulfur Batteries
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聚噻吩和硫的共聚提高锂硫电池的电化学性能
DOI：
10.1021/acs.chemmater.5b02317
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发表时间：
2015
影响因子：
8.6
通讯作者：
R. Zentel
中科院分区：
文献类型：
--
作者：
B. Oschmann;J. Park;C. Kim;K. Char;Y.-E. Sung;R. Zentel
本文首次报道了硫与烯丙基端聚（3-己基噻吩-2,5-二基）（P3HT）的格氏复分解聚合。这种共聚是通过s8环烯丙基端基热解裂解形成的硫自由基的转化而实现的。共聚物中C-S键的形成通过多种方法进行表征，包括核磁共振波谱、粒径排除色谱和近边缘x射线吸收精细光谱。该-P3HT共聚物被用作硫的添加剂，作为锂硫电池的正极材料，并与硫和P3HT的简单混合物进行了比较，其中硫和P3HT没有共价连接。虽然P3HT与基本硫不相容，但news -P3HT共聚物可以很好地分散在硫中，至少在亚微米水平上。含有s - p3ht共聚物的硫电池在0.5C下的循环性能（s - p3ht共聚物在100次循环后的799 mAh g - 1，而简单混合物仅为544 mAh g - 1）和c倍率性能方面表现出增强的电池性能。这是由于多硫化物和P3HT之间的相互作用阻碍了多硫化物的溶解和电荷转移（通过电化学阻抗谱证明），这是由于P3HT通过硫和P3HT的共价连接均匀地结合到硫中。
We first report on the copolymerization of sulfur and allyl-terminated poly(3-hexylthiophene-2,5-diyl) (P3HT) derived by Grignard metathesis polymerization. This copolymerization is enabled by the conversion of sulfur radicals formed by thermolytic cleavage of S8rings with allyl end-group. The formation of a C–S bond in the copolymer is characterized by a variety of methods, including NMR spectroscopy, size exclusion chromatography, and near-edge X-ray absorption fine spectroscopy. TheS-P3HTcopolymer is applied as an additive to sulfur as cathode material in lithium–sulfur batteries and compared to the use of a simple mixture of sulfur and P3HT, in which sulfur and P3HT were not covalently linked. While P3HT is incompatible with elementary sulfur, the newS-P3HTcopolymer can be well dispersed in sulfur, at least on the sub-micrometer level. Sulfur batteries containing theS-P3HTcopolymer exhibit an enhanced battery performance with respect to the cycling performance at 0.5C (799 mAh g–1after 100 cycles forS-P3HTcopolymer versus only 544 mAh g–1for the simple mixture) and the C-rate performance. This is attributed to the attractive interaction between polysulfides and P3HT hindering the dissolution of polysulfides and the charge transfer (proven by electrochemical impedance spectroscopy) due to the homogeneous incorporation of P3HT into sulfur by covalently linking sulfur and P3HT.
影响因子：
29.4
作者：
Loewe, RS;Khersonsky, SM;McCullough, RD
通讯作者：
McCullough, RD