Kim Hee Min, Hwang Jang-Yeon, Manthiram Arumugam, Sun Yang-Kook
Department of Energy Engineering, Hanyang University , Seoul 133-791, South Korea.
Materials Science and Engineering Program and Texas Materials Institute, The University of Texas at Austin , Austin, Texas 78712, United States.
ACS Appl Mater Interfaces. 2016 Jan 13;8(1):983-7. doi: 10.1021/acsami.5b10812. Epub 2016 Jan 4.
Elemental sulfur electrode has a huge advantage in terms of charge-storage capacity. However, the lack of electrical conductivity results in poor electrochemical utilization of sulfur and performance. This problem has been overcome to some extent previously by using a bare multiwall carbon nanotube (MWCNT) paper interlayer between the sulfur cathode and the polymeric separator, resulting in good electron transport and adsorption of dissolved polysulfides. To advance the interlayer concept further, we present here a self-assembled MWCNT interlayer fabricated by a facile, low-cost process. The Li-S cells fabricated with the self-assembled MWCNT interlayer and a high loading of 3 mg cm(-2) sulfur exhibit a first discharge specific capacity of 1112 mAh g(-1) at 0.1 C rate and retain 95.8% of the capacity at 0.5 C rate after 100 cycles as the self-assembled MWCNT interlayer facilitates good interfacial contact between the interlayer and the sulfur cathode and fast electron and lithium-ion transport while trapping and reutilizing the migrating polysulfides. The approach presented here has the potential to advance the commercialization feasibility of the Li-S batteries.
元素硫电极在电荷存储容量方面具有巨大优势。然而，缺乏导电性导致硫的电化学利用率和性能较差。此前，通过在硫阴极和聚合物隔膜之间使用裸多壁碳纳米管（MWCNT）纸夹层，在一定程度上克服了这个问题，实现了良好的电子传输以及对溶解多硫化物的吸附。为了进一步推进夹层概念，我们在此展示一种通过简便、低成本工艺制备的自组装MWCNT夹层。采用自组装MWCNT夹层和3 mg cm(-2)高负载硫制成的锂硫电池，在0.1 C倍率下首次放电比容量为1112 mAh g(-1)，在0.5 C倍率下经过100次循环后仍保留95.8%的容量，因为自组装MWCNT夹层促进了夹层与硫阴极之间良好的界面接触以及快速的电子和锂离子传输，同时捕获并再利用迁移的多硫化物。本文提出的方法有潜力推进锂硫电池的商业化可行性。
