Thiophene organic molecules in-situ grafted mesoporous carbon promote high stable and high kinetic lithium-sulfur batteries

Abstract

Lithium‑sulfur (LiS) batteries are widely regarded as the promising battery system that meet the high energy density requirement up to 500 Wh kg−1. However, the serious shuttle effect and poor reaction kinetics seriously slow down the practical application of LiS batteries. For both solid and liquid LiS batteries, holding sulfides by adsorptive and catalytic host is an indispensable strategy to improve their reaction kinetic. Carbonaceous materials have been widely used as the sulfur hosts due to their easy controlled morphologic, lightweight and low-cost. However, these advantages were usually shelved by their low wettability and poor adsorption to polysulfides. In this study, a high active and stable carbonaceous host was synthesized by in-situ grafting thiophene molecules on mesoporous carbon. Sulfur was further bond on the thiophene molecules to form an extremely stable electrode structure. More importantly, the electron-rich conjugated thiophene molecules, which with high ionic and electronic conductivity, can effectively improve the reaction kinetics of LiS batteries. This simple and reproducible cathode modification strategy provides a reliable reference for realizing the practical application of LiS batteries.