Zhu Acheng, Li Shaokai, Yang Yuting, Peng Bo, Cheng Yuwen, Kang Qi, Zhuang Zechao, Ma Lianbo, Xu Jie
School of Materials Science and Engineering, Anhui University of Technology, Ma'anshan, 243002, P. R. China.
Luzhou Dongfang Agrochemical Co. Ltd., Hangzhou Branch, Zhejiang, 310000, P. R. China.
Small. 2024 Feb;20(7):e2305494. doi: 10.1002/smll.202305494. Epub 2023 Oct 5.
Lithium-sulfur (Li-S) batteries hold the superiority of eminent theoretical energy density (2600 Wh kg ). However, the ponderous sulfur reduction reaction and the issue of polysulfide shuttling pose significant obstacles to achieving the practical wide-temperature operation of Li-S batteries. Herein, a covalent organic nanosheet-wrapped carbon nanotubes (denoted CON/CNT) composite is synthesized as an electrocatalyst for wide-temperature Li-S batteries. The design incorporates the CON skeleton, which contains imide and triazine functional units capable of chemically adsorbing polysulfides, and the underlaid CNTs facilitate the conversion of captured polysulfides enabled by enhanced conductivity. The electrocatalytic behavior and chemical interplay between polysulfides and the CON/CNT interlayer are elucidated by in situ X-ray diffraction detections and theoretical calculations. Resultantly, the CON/CNT-modified cells demonstrate upgraded performances, including wide-temperature operation ranging from 0 to 65 °C, high-rate performance (625 mAh g at 5.0 C), exceptional high-rate cyclability (1000 cycles at 5.0 C), and stable operation under high sulfur loading (4.0 mg cm ) and limited electrolyte (5 µL mg ). These findings might guide the development of advanced Li-S batteries.
锂硫（Li-S）电池具有卓越的理论能量密度（2600 Wh kg）优势。然而，缓慢的硫还原反应和多硫化物穿梭问题对实现Li-S电池的实际宽温度运行构成了重大障碍。在此，合成了一种共价有机纳米片包裹的碳纳米管（记为CON/CNT）复合材料作为宽温度Li-S电池的电催化剂。该设计包含CON骨架，其含有能够化学吸附多硫化物的酰亚胺和三嗪功能单元，下层的碳纳米管通过增强的导电性促进捕获的多硫化物的转化。通过原位X射线衍射检测和理论计算阐明了多硫化物与CON/CNT中间层之间的电催化行为和化学相互作用。结果，CON/CNT修饰的电池表现出升级的性能，包括0至65°C的宽温度运行、高倍率性能（5.0 C时为625 mAh g）、出色的高倍率循环稳定性（5.0 C时1000次循环）以及在高硫负载（4.0 mg cm）和有限电解质（5 µL mg）下的稳定运行。这些发现可能会指导先进Li-S电池的发展。
