Song Xueqin, Tian Da, Qiu Yue, Sun Xun, Jiang Bo, Zhao Chenghao, Zhang Yu, Xu Xianzhu, Fan Lishuang, Zhang Naiqing
School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, China.
Academy of Fundamental and Interdisciplinary Sciences, Harbin Institute of Technology, Harbin, 150001, China.
Small. 2021 Oct;17(42):e2102962. doi: 10.1002/smll.202102962. Epub 2021 Sep 14.
Polysulfide shuttling and sluggish sulfur redox kinetics hinder the cyclability and rate capability of lithium-sulfur (Li-S) batteries. The intrinsic redox kinetics of sulfur cathodes strongly depends on the interaction between catalysts and sulfur species. Herein, N-doped CoTe is proposed as an effective dual-anchoring electrocatalyst, which can simultaneously bind Li and S atoms in lithium polysulfides via ionic Te-Li/N-Li bonding and coordinate covalent Co-S bonding. The incorporated N not only serves as enhanced lithiophilic site, but also an agent to improve the sulfiphilicity of the Co site as revealed by a series of experimental and computational results. Benefiting from these superiorities, the use of N-doped CoTe as a catalytic interlayer enables efficient operation of Li-S batteries in terms of impressive rate capability of 758 mAh g at 4 C and very low capacity decay of 0.021% per cycle over 1000 cycles. The material and strategy demonstrated in this work may open the door toward developing more advanced Li-S electrocatalysts.
多硫化物穿梭效应和缓慢的硫氧化还原动力学阻碍了锂硫（Li-S）电池的循环性能和倍率性能。硫阴极的本征氧化还原动力学很大程度上取决于催化剂与硫物种之间的相互作用。在此，提出了一种N掺杂的CoTe作为有效的双锚定电催化剂，它可以通过离子Te-Li/N-Li键和配位共价Co-S键同时结合多硫化锂中的Li和S原子。一系列实验和计算结果表明，掺入的N不仅作为增强的亲锂位点，还作为提高Co位点亲硫性的试剂。受益于这些优势，使用N掺杂的CoTe作为催化中间层能够使Li-S电池高效运行，在4 C时具有758 mAh g的令人印象深刻的倍率性能，并且在1000次循环中每循环的容量衰减非常低，仅为0.021%。这项工作中展示的材料和策略可能为开发更先进的Li-S电催化剂打开大门。
