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

• Published in: Nanoscale advances 2024-12, Vol.6 (24), p.6386-6397
• 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
• ISSN: 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 2 QDs-CNTs/S@Ni(OH) 2 (labeled as MoS 2 QDs-CNTs/S@NH) cathode was synthesized via a hydrothermal process, in which conductive polar MoS 2 quantum dot-decorated carbon nanotube (CNT) networks coated with an ultrathin Ni(OH) 2 layer acted as an efficient electrocatalyst. MoS 2 QD nanoparticles with a high conductivity and catalytic nature can enhance the kinetics of polysulfide conversion, expedite Li 2 S nucleation, and decrease the reaction energy barrier. The thin outer Ni(OH) 2 layer physically confines active sulfur and meanwhile provides abundant sites for adsorption and conversion of polysulfides. Benefiting from these merits, a battery using MoS 2 QDs-CNTs/S@NH as the sulfur host cathode exhibits excellent electrochemical performances with rate capabilities of 953.7 mA h g −1 at 0.1C and 606.6 mA h g −1 at 2.0C. A prominent cycling stability of a 0.052% decay rate per cycle after 800 cycles is achieved even at 2C. Schematic illustration of the synthesis process of MoS 2 QDs-CNTs/S@NH composites.