Accelerating the redox kinetics by catalytic activation of “dead sulfur” in lithium–sulfur batteries

Abstract

With the merits of high energy density and environmental friendliness, the lithium–sulfur battery (LSB) has been perceived as a next-era energy storage device. However, issues such as the insulating nature of sulfur, polysulfide shuttling, huge volume change, and tardy polysulfide intermediate conversion cause rapid capacity decay, severe self-discharging, and drastic drop in coulombic efficiency, and impede the commercialization of LSBs. Many working steps of LSBs suffer from the problem of “dead sulfur”, which can no longer be cycled for various reasons. How to suppress “dead sulfur” and improve the reaction kinetics has been a major research interest in recent years. Among numerous studies that aim to solve these problems, the search for more efficient catalytic materials that facilitate polysulfide intermediate conversion and chemically anchor soluble lithium polysulfides has drawn increasing attention. This review focuses on the design and mechanistic interpretation of various advanced catalytic materials for the activation of “dead sulfur” in LSBs.