Confining Sulfur in Integrated Composite Scaffold with Highly Porous Carbon Fibers/Vanadium Nitride Arrays for High-Performance Lithium-Sulfur Batteries
Confining Sulfur in Integrated Composite Scaffold with Highly Porous Carbon Fibers/Vanadium Nitride Arrays for High-Performance Lithium-Sulfur Batteries
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DOI：
10.1002/adfm.201706391
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发表时间：
2018-09-19
影响因子：
19
通讯作者：
Tu, Jiangping
中科院分区：
文献类型：
--
作者：
Zhong, Yu;Chao, Dongliang;Tu, Jiangping
提高硫电极的利用效率和抑制中间多硫化物的“穿梭效应”是高性能锂硫电池（LSB）的关键挑战。本文报道了一种简单的组合策略，通过简单的化学蚀刻联合溶剂热-超临界流体方法制备新型多孔碳纤维/氮化钒阵列（PCF/VN）复合材料支架用于储存硫。PCF/VN/S集成电极可将更多的活性硫储存在PCF/VN骨架中，并实现了对多硫化物的“物理阻挡和化学吸收”的双重阻挡效应。具有高度多孔结构的PCF提供了大的空间来容纳活性硫，并且具有交联的迷宫通道来物理地包裹多硫化物物种。VN纳米带阵列表现出很强的化学锚定多硫化物的能力，从而延缓穿梭效应。由于PCF/VN/S电极的独特结构和双重限制效应，该电极在0.1C时具有1310.8mAh g（-1）的高可逆容量，250次循环后的循环寿命为1052.5mAh g（-1），并且比CF/VN/S、PCF/S和CF/S电极具有更好的倍率性能。这项工作为制造用于LSB的高性能集成电极打开了一扇新的大门。
Increasing the utilization efficiency of sulfur electrodes and suppressing the "shuttle effect" of intermediate polysulfides are the key challenge for high-performance lithium-sulfur batteries (LSBs). Herein a facile combined strategy is reported to fabricate novel porous carbon fibers/vanadium nitride arrays (PCF/VN) composite scaffold for the storage of sulfur via a facile chemical etching united solvothermal-supercritical fluid method. More active sulfur can be stored in the PCF/VN backbone and dual blocking effects associated with "physical block and chemical absorption" for polysulfides are achieved in the PCF/VN/S integrated electrode. The PCF with highly porous structure provides large space to accommodate active sulfur and possesses cross-linked maze channels to physically immobilize the polysulfide species. The VN nanobelt arrays demonstrate strong ability for chemically anchoring the polysulfides, thus retarding the shuttle effect. Due to the unique structure and dual confining effect, the designed PCF/VN/S electrode shows a high reversible capacity of 1310.8 mA h g(-1) at 0.1 C, an extended cycle life (1052.5 mA h g(-1) after 250 cycles) as well as enhanced rate capability, much better than other counterparts (CF/VN/S, PCF/S, and CF/S). This work opens a new door for fabricating high-performance integrated electrodes for LSBs.