Nano‐LaMnO3 Modified Separator for Enhanced Redox Reaction Kinetics and Electrochemical Performance of Lithium‐Sulfur Batteries

Abstract

AbstractThe “shuttle effect” and sluggish conversion reaction kinetics of polysulfides seriously hinder the practical application of Li−S batteries. In this study, nano‐sized LaMnO3 (N‐LMO) with typical perovskite structure combined with highly‐conductive carbon black (SP) was introduced on the commercial separator to fabricate a functional surface modification. It is found that the polar N‐LMO with abundant active sites offers strong chemisorption towards the soluble polysulfides meanwhile accelerates their redox conversion, and the conductive SP contributes to extra spots to reactivate the trapped sulfur species. Consequently, the synergistic effect of adsorption‐catalysis‐conduction built by the cooperative N‐LMO/SP modification greatly enhances the sulfur redox kinetics as well as suppresses the polysulfide shuttling not at the expense of weakening Li‐ion transport, which endows the Li−S cell with a high initial discharge capacity of 1143.6 mAh g−1 at 0.2 C and a capacity decay rate of only 0.072 % per cycle at 1 C over 500 cycles.