MoS 2 quantum dot-decorated CNT networks as a sulfur host for enhanced electrochemical kinetics in advanced lithium-sulfur batteries

• Published in: Nanoscale advances 2024-10
• Main Authors: Wei, Meng, Lu, Hanqing, Wang, Zhen, Lu, Baowen, Wang, Pengtao, Zhang, Xinxin, Feng, Bingjie, Xie, Yingjie, Zhang, Tao, Liu, Guanghui, Xu, Song
• Format: Article
• Language: English
• ISSN: 2516-0230; 2516-0230
• DOI: 10.1039/D4NA00068D

The slow redox kinetics and shuttle effect of polysulfides severely obstruct the further development of lithium-sulfur (Li-S) batteries. Constructing sulfur host materials with high conductivity and catalytic capability is well acknowledged as an effective strategy for promoting polysulfide conversion. Herein, a well-designed MoS QDs-CNTs/S@Ni(OH) (labeled as MoS QDs-CNTs/S@NH) cathode was synthesized a hydrothermal process, in which conductive polar MoS quantum dot-decorated carbon nanotube (CNT) networks coated with an ultrathin Ni(OH) layer acted as an efficient electrocatalyst. MoS QD nanoparticles with a high conductivity and catalytic nature can enhance the kinetics of polysulfide conversion, expedite Li S nucleation, and decrease the reaction energy barrier. The thin outer Ni(OH) layer physically confines active sulfur and meanwhile provides abundant sites for adsorption and conversion of polysulfides. Benefiting from these merits, a battery using MoS QDs-CNTs/S@NH as the sulfur host cathode exhibits excellent electrochemical performances with rate capabilities of 953.7 mA h g at 0.1C and 606.6 mA h g at 2.0C. A prominent cycling stability of a 0.052% decay rate per cycle after 800 cycles is achieved even at 2C.