Sulfur/carbon nanocomposite-filled polyacrylonitrile nanofibers as a long life and high capacity cathode for lithium-sulfur batteries
Sulfur/carbon nanocomposite-filled polyacrylonitrile nanofibers as a long life and high capacity cathode for lithium-sulfur batteries
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硫/碳纳米复合材料填充聚丙烯腈纳米纤维作为锂硫电池的长寿命和高容量阴极
DOI：
10.1039/c4ta06976e
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发表时间：
2015
影响因子：
11.9
通讯作者：
Ai Xinping
中科院分区：
文献类型：
--
作者：
Ye Jian;He Feng;Nie Jia;Cao Yuliang;Yang Hanxi;Ai Xinping
合成了硫/碳(S/C)纳米复合填充聚丙烯腈(PAN)纳米纤维(S/C/PAN)作为锂硫(Li-S)电池长寿命高容量正极材料。在S/C/PAN纳米纤维中，硫化的PAN基质不仅作为离子和电子通道使Li+和电子到达S/C纳米粒子并与之反应，而且还作为保护屏障防止S/C纳米粒子与电解液接触，从而防止硫的放电中间体溶解在有机碳酸盐电解液中并与之反应。由于硫在纳米纤维中的氧化还原反应主要发生在S/C界面的内部，因此纳米纤维阴极的微观结构和电化学界面在重复循环中保持稳定。结果表明，S/C/PAN正极材料在200 mA g−1倍率下的可逆容量为1179 mA h g−1，几次循环后的库仑效率为100%，在4.0A g∼1下的倍率为616 mA h g−1，循环稳定性好，400次循环容量保持率可达60%，具有广阔的应用前景。
Sulfur/carbon (S/C) nanocomposite-filled polyacrylonitrile (PAN) nanofibers (denoted as S/C/PAN) are synthesized as a long life and high capacity cathode material for lithium–sulfur (Li–S) batteries. In the S/C/PAN nanofibers, the sulfurized PAN matrix acts not only as ionic and electronic channels to allow Li+ and electrons to arrive at and react with the S/C nanoparticles, but also as a protective barrier to prevent the S/C nanoparticles from contacting the electrolyte, thus avoiding the discharge intermediates of sulfur to dissolve in and react with the organic carbonate electrolyte. Since the redox reaction of sulfur in the nanofibers occurs mostly at the interior S/C interface through a solid state reaction mechanism, the microstructures and electrochemical interfaces in the nanofiber cathode remain stable during repeated cycles. As a consequence, the S/C/PAN cathode demonstrates a high reversible capacity of 1179 mA h g−1 at a current rate of 200 mA g−1, a high Coulombic efficiency of ∼100% after a few cycles, a good rate capability with 616 mA h g−1 at 4.0 A g−1 and a long cycling stability with 60% capacity retention over 400 cycles, showing great prospect for Li–S battery applications.