Chen Minghua, Zhang Zhanpeng, Liu Xiaoxue, Li Yu, Wang Yuqing, Fan He, Liang Xinqi, Chen Qingguo
Key Laboratory of Engineering Dielectric and Applications (Ministry of Education), Harbin University of Science and Technology Harbin 150080 P. R. China
RSC Adv. 2020 Aug 27;10(53):31773-31779. doi: 10.1039/d0ra04901h. eCollection 2020 Aug 26.
Lithium-sulfur (Li-S) batteries with their outstanding theoretical energy density are strongly considered to take over the post-lithium ion battery era; however, they are limited by sluggish reaction kinetics and the severe shuttling of soluble lithium polysulfides. Prussian blue analogues (PBs) have demonstrated their efficiency in hindering the shuttle effects as host materials of sulfur; unfortunately, they show an inferior electronic conductivity, exhibiting considerable lifespan but poor rate performance. Herein, we rationally designed a PB@reduced graphene oxide as the host material for sulfur (S@PB@rGO) hybrids a facile liquid diffusion and physical absorption method, in which the sulfur was integrated into NaCo[Fe(CN)] and rGO framework. When employed as a cathode, the as-prepared hybrid exhibited excellent rate ability (719 mA h g at 1C) and cycle stability (918 mA h g at 0.5C after 100 cycles). The improved electrochemical performance was attributed to the synergetic effect of PB and conductive rGO, which not only enhanced the physisorption of polysulfides but also provided a conductive skeleton to ensure rapid charge transfer kinetics, achieving high energy/power outputs and considerable lifespan simultaneously. This study may offer a new method manufacturing high performance Li-S batteries.
锂硫（Li-S）电池因其出色的理论能量密度而被强烈认为将引领后锂离子电池时代；然而，它们受到反应动力学缓慢和可溶性多硫化锂严重穿梭的限制。普鲁士蓝类似物（PBs）作为硫的主体材料已证明其在阻碍穿梭效应方面的有效性；不幸的是，它们表现出较差的电子导电性，虽然具有可观的使用寿命，但倍率性能不佳。在此，我们通过一种简便的液体扩散和物理吸附方法，合理设计了一种PB@还原氧化石墨烯作为硫（S@PB@rGO）复合材料的主体材料，其中硫被整合到NaCo[Fe(CN)]和rGO框架中。当用作阴极时，所制备的复合材料表现出优异的倍率性能（1C下为719 mA h g）和循环稳定性（100次循环后0.5C下为918 mA h g）。电化学性能的改善归因于PB和导电rGO的协同效应，这不仅增强了对多硫化物的物理吸附，还提供了一个导电骨架以确保快速的电荷转移动力学，同时实现高能量/功率输出和可观的使用寿命。这项研究可能为制造高性能锂硫电池提供一种新方法。
