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Theoretical Calculation Guided Design of Single-Atom Catalysts toward Fast Kinetic and Long-Life Li-S Batteries.
Nano Letters ( IF 9.6 ) Pub Date : 2020-01-03 , DOI: 10.1021/acs.nanolett.9b04719
Guangmin Zhou 1, 2 , Shiyong Zhao 3 , Tianshuai Wang 4 , Shi-Ze Yang 5 , Bernt Johannessen 6 , Hao Chen 1 , Chenwei Liu 1 , Yusheng Ye 1 , Yecun Wu 1 , Yucan Peng 1 , Chang Liu 7 , San Ping Jiang 3 , Qianfan Zhang 4 , Yi Cui 1, 8
Affiliation  

Lithium-sulfur (Li-S) batteries are promising next-generation energy storage technologies due to their high theoretical energy density, environmental friendliness, and low cost. However, low conductivity of sulfur species, dissolution of polysulfides, poor conversion from sulfur reduction, and lithium sulfide (Li2S) oxidation reactions during discharge-charge processes hinder their practical applications. Herein, under the guidance of density functional theory calculations, we have successfully synthesized large-scale single atom vanadium catalysts seeded on graphene to achieve high sulfur content (80 wt % sulfur), fast kinetic (a capacity of 645 mAh g-1 at 3 C rate), and long-life Li-S batteries. Both forward (sulfur reduction) and reverse reactions (Li2S oxidation) are significantly improved by the single atom catalysts. This finding is confirmed by experimental results and consistent with theoretical calculations. The ability of single metal atoms to effectively trap the dissolved lithium polysulfides (LiPSs) and catalytically convert the LiPSs/Li2S during cycling significantly improved sulfur utilization, rate capability, and cycling life. Our work demonstrates an efficient design pathway for single atom catalysts and provides solutions for the development of high energy/power density Li-S batteries.

中文翻译:

针对快速动力学和长寿命Li-S电池的单原子催化剂的理论计算指导设计。

锂硫(Li-S)电池具有较高的理论能量密度,环境友好性和低成本,因此有望成为下一代储能技术。但是,硫物质的低电导率,多硫化物的溶解,硫还原反应的转化率差以及放电-充电过程中的硫化锂(Li2S)氧化反应阻碍了它们的实际应用。本文中,我们在密度泛函理论计算的指导下,成功地合成了在石墨烯上播种的大规模单原子钒催化剂,以实现高硫含量(硫含量为80 wt%),快速动力学(3容量为645 mAh g-1) C率)和长寿命的Li-S电池。单原子催化剂可显着改善正反应(硫还原反应)和逆反应(Li 2 S氧化反应)。实验结果证实了这一发现,并与理论计算相符。单个金属原子有效地捕获溶解的多硫化锂(LiPSs)并在循环过程中催化转化LiPSs / Li2S的能力显着提高了硫的利用率,速率能力和循环寿命。我们的工作展示了单原子催化剂的有效设计途径,并为开发高能量/功率密度Li-S电池提供了解决方案。
更新日期:2020-01-04
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