Modifying polysulfide conversion and confinement by employing MoS2 nanofiber interlayer for high electrochemical performance

Abstract

Owing to the high-energy density and specific capacity, lithium-sulfur batteries are regarded as the most promising energy storage systems, whereas the wide applications of lithium-sulfur batteries are hindered by the severe “shuttle effect” and sluggish redox kinetics of lithium polysulfides. Many strategies have been applied to modify the electrochemical performance, including preparing suitable sulfur hosts, designing functional interlayer, and protecting the lithium anode. Among these strategies, designing functional interlayers is considered as an efficient method to inhibit the shuttle effect and improve the redox kinetics of lithium polysulfides. Herein, MoS2 nanofiber (MSNF) interlayers are prepared and used in the lithium-sulfur batteries. On the one hand, the polysulfide migration could be inhibited due to the chemical adsorption between MoS2 and polysulfide. On the other hand, due to the 3D nanofiber structure of MoS2, it could provide the rapid electron/ion transport and fast redox kinetics. As a result, the lithium-sulfur batteries with MSNF interlayers display high specific capacity and excellent cycling stability.