Suppress Loss of Polysulfides in Lithium-Sulfur Battery by Regulating the Rate-Determining Step via 1T MoS2-MnO2 Covering Layer.

Abstract

The commercialization of lithium-sulfur batteries (LSBs) is obstructed by several technical challenges, the most severe of which is the irreversible loss of soluble polysulfide intermediates. These soluble polysulfides must be anchored or confined in the cathode side to maintain the long life of the LSBs. Here, 1T MoS2-MnO2/CC heterostructure functional covering layer is designed to regulate the rate-determining step from the liquid-to-solid reaction to solid-to-solid reaction. Rapid and uniform nucleation of solid Li2S2/Li2S is therefore achieved, and the loss of soluble polysulfides is retarded. The Li-S batteries assembled with 1T MoS2-MnO2/CC covering layer therefore deliver outstanding rate capabilities even under high sulfur loads and large current rates. This study paves a novel way to suppress the polysulfides' "farewell effect" from the perspective of the kinetics.