Abstract Lithium–sulfur (Li–S) battery is considered as one of the most promising advanced energy storage devices. However, several critical issues remain which restrict their practical applications, especially the shuttle effect of soluble lithium polysulfides. Herein, we designed a lightweight multifunctional layer comprising reduced graphene oxide (rGO) and cobalt/nitrogen co-doped carbon nanofibers (Co-N-C) to modified the polypropylene (PP) separator to facilitate the electrochemical performance of Li–S batteries. The Co-N-C/rGO layer with abundant mesopores possesses strong immobilization ability of polysulfides and high electronic conductivity, which could work as an intrinsic physical/chemical frame work barrier and an upper current collector to trap and reutilize the polysulfides. Consequently, the Li–S battery with the modified Co-N-C/rGO/PP separator exhibits excellent cycling performance and good rate capability. A high discharge capacity of 1344 mAh g–1 at 0.1 C, 658 mAh g–1 at 5 C and a low capacity degradation rate of 28.8% after 500 cycles at 0.5 C were obtained. These exciting results indicate that this multifunctional Co-N-C/rGO/PP separator could be a promising separator candidate for Li–S batteries.

中文翻译：

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一种用于锂硫电池的钴氮共掺杂多孔碳纳米纤维改性多功能隔膜

摘要 锂硫（Li-S）电池被认为是最有前途的先进储能装置之一。然而，仍然存在一些限制其实际应用的关键问题，尤其是可溶性多硫化锂的穿梭效应。在此，我们设计了一种包含还原氧化石墨烯 (rGO) 和钴/氮共掺杂碳纳米纤维 (Co-NC) 的轻质多功能层来改性聚丙烯 (PP) 隔膜，以促进 Li-S 电池的电化学性能。具有丰富介孔的 Co-NC/rGO 层具有很强的多硫化物固定能力和高电子电导率，可作为内在的物理/化学框架屏障和上部集电器来捕获和再利用多硫化物。最后，带有改性 Co-NC/rGO/PP 隔膜的 Li-S 电池表现出优异的循环性能和良好的倍率性能。获得了 0.1 C 下 1344 mAh g-1 的高放电容量，5 C 下 658 mAh g-1 的高放电容量和 0.5 C 下 500 次循环后的 28.8% 低容量退化率。这些令人兴奋的结果表明，这种多功能 Co-NC/rGO/PP 隔膜可能是 Li-S 电池的一种有前途的隔膜候选者。