Inhibiting polysulfide shuttling using dual-functional nanowire/nanotube modified layers for highly stable lithium-sulfur batteries
Inhibiting polysulfide shuttling using dual-functional nanowire/nanotube modified layers for highly stable lithium-sulfur batteries
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使用双功能纳米线/纳米管改性层抑制多硫化物穿梭以获得高度稳定的锂硫电池
DOI：
10.1039/c9nj03320c
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发表时间：
2019
影响因子：
3.3
通讯作者：
Huang Wei
中科院分区：
文献类型：
--
作者：
Wang Yizhou;Liu Wenhui;Liu Ruiqing;Pan Peifeng;Suo Liyao;Chen Jun;Feng Xiaomiao;Wang Xizhang;Ma Yanwen;Huang Wei
可溶性多硫化物（PSs）的穿梭效应严重影响了锂硫电池的循环性能，阻碍了锂硫电池的实际应用。为了抑制PS穿梭效应，我们在商用聚丙烯（PP）分离器上直接涂覆一层与碳纳米管（CNTs）交错的超长一维MnO2纳米线（NWs）。这种MnO2/CNT修饰层具有双重功能，可以有效地捕获和再利用溶解的PS，其中MnO2 NWs允许PS的化学吸附，而CNTs形成导电网络进行电子转移以加速PS氧化还原反应。同时，由于NWs和纳米管形成的多孔结构，不会影响锂离子的迁移。与纯MnO2 NW或碳纳米管改性的MnO2/CNT/PP分离器相比，该MnO2/CNT/PP分离器可以显著抑制PS的穿梭。使用最佳的隔膜，我们展示了一种高度稳定的Li-S电池，在1C下的初始容量为843.7 mA h g−1，在500次循环中容量保持率为68.03%。本研究展示了一种用于抑制高稳定锂电池PS穿梭效应的改性隔膜的综合设计策略。
The shuttle effect of dissolvable polysulfides (PSs) severely deteriorates the cycling performances of lithium–sulfur (Li–S) batteries and consequently hampers their practical application. To inhibit the PS shuttle effect, here we designed a modified separator by directly coating a thin layer of ultralong one-dimensional MnO2 nanowires (NWs) interlaced with carbon nanotubes (CNTs) on a commercial polypropylene (PP) separator. Such a MnO2/CNT modified layer exhibits dual functions to effectively trap and reutilize the dissolved PSs, where the MnO2 NWs allow the chemical adsorption of the PSs while the CNTs form a conductive network for electron transfer to accelerate the PS redox reaction. Meanwhile, the migration of lithium ions will not be influenced due to the porous structure formed by these NWs and nanotubes. This MnO2/CNT/PP separator can significantly inhibit PS shuttling in comparison with neat MnO2 NW or CNT modified separators. Using the optimal separator, we demonstrate a highly stable Li–S battery with an initial capacity of 843.7 mA h g−1 at 1C, and a capacity retention of 68.03% over 500 cycles. This study shows a comprehensive design strategy for a modified separator to inhibit the PS shuttle effect for highly stable Li–S batteries.