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Mesoporous Yolk-Shell Structured Organosulfur Nanotubes with Abundant Internal Joints for High-Performance Lithium–Sulfur Batteries by Kinetics Acceleration
Small ( IF 13.0 ) Pub Date : 2021-08-04 , DOI: 10.1002/smll.202101857
Wei Chang 1, 2 , Jin Qu 1 , Wei Li 1 , Yu-Hao Liu 1 , Xian-Zhi Zhai 2 , Hong-Jun Liu 2 , Yu Kang 3 , Zhong-Zhen Yu 2
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Although organosulfur compounds can protect lithium anodes, participate in the redox reaction, and suppress the shuttle effect, the sluggish electrochemical dynamics of their bulk structure and the notorious shuttle effect of covalent long-chain sulfurs largely impede their actual applications. Herein, sulfurized carbon nanotube@aminophenol-formaldehyde (SC@A) with covalently linked short-chain sulfurs is firstly synthesized by in situ polymerization of aminophenol-formaldehyde (AF) on the surface of carbon nanotubes (CNTs) followed by acetone etching and inverse sulfurization processes, forming mesoporous yolk-shell organosulfur nanotubes with abundant internal joints between the yolk of CNTs and the shell of sulfurized AF for the first time. In situ Raman spectra, in situ XRD patterns, and ex situ XPS spectra verify that the covalent short-chain sulfurs bring about a reversible solid-solid conversion process of sulfur, thoroughly avoiding the shuttle effect. The mesoporous yolk-shell structure with abundant internal joints can effectively accommodate the volume change, fully expose active sites and efficiently improve the transport of electrons and lithium ions, thus highly promoting the solid–solid electrochemical reaction kinetics. Therefore, the SC@A cathode exhibits a superior specific capacity of 841 mAh g−1 and a capacity decay of 0.06% per cycle within 500 cycles at a large current density of 5.0 C.

中文翻译:

具有丰富内部接头的介孔蛋黄-壳结构有机硫纳米管通过动力学加速用于高性能锂硫电池

虽然有机硫化合物可以保护锂负极,参与氧化还原反应,抑制穿梭效应,但其本体结构缓慢的电化学动力学和共价长链硫臭名昭著的穿梭效应在很大程度上阻碍了它们的实际应用。在此,首先通过在碳纳米管(CNT)表面原位聚合氨基苯酚甲醛(AF),然后丙酮蚀刻和逆反应合成了具有共价键连接的短链硫的硫化碳纳米管@氨基苯酚甲醛(SC@A)。在硫化过程中,首次形成了介孔蛋黄-壳有机硫纳米管,在 CNT 的蛋黄和硫化 AF 的壳之间具有丰富的内部接头。原位拉曼光谱、原位XRD图谱、和非原位 XPS 光谱验证了共价短链硫带来了可逆的硫固-固转化过程,彻底避免了穿梭效应。具有丰富内部接头的介孔蛋黄壳结构可以有效地适应体积变化,充分暴露活性位点,有效改善电子和锂离子的传输,从而极大地促进了固-固电化学反应动力学。因此,SC@A正极表现出841 mAh g的优异比容量 从而高度促进固-固电化学反应动力学。因此,SC@A正极表现出841 mAh g的优异比容量 从而高度促进固-固电化学反应动力学。因此,SC@A正极表现出841 mAh g的优异比容量−1,在 5.0 C 的大电流密度下,500 次循环内每循环容量衰减 0.06%。
更新日期:2021-09-23
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