Multifunctional Heterostructures for Polysulfide Suppression in High-Performance Lithium-Sulfur Cathode

Small. 2018 Dec;14(49):e1803134. doi: 10.1002/smll.201803134. Epub 2018 Oct 25.

Abstract

The commercialization of lithium-sulfur (Li-S) batteries is greatly hindered due to serious capacity fading caused by the polysulfide shuttling effect. Optimizing the structural configuration, enhancing reaction kinetics of the sulfur cathode, and increasing areal sulfur loading are of great significance for promoting the commercial applications of Li-S batteries. Herein, the multifunctional polysulfide scavengers based on nitrogen, sulfur co-doped carbon cloth (DCC), which is supported by flower-like MoS2 (1T-2H) decorated with BaMn0.9 Mg0.1 O3 perovskite particle (PrNP) and carbon nanotubes (CNTs), namely, DCC@MoS2 /PrNP/CNTs, are delicately designed and synthesized. The physical confinement, chemical coupling, and catalysis conversion for active sulfur are achieved simultaneously in this polysulfide motif. Due to these merits, the as-fabricated self-supported DCC@MoS2 /PrNP/CNTs/S manifests an excellent reversible areal capacity of 4.75 mAh cm-2 with an ultrahigh sulfur loading of 5.2 mg cm-2 at the 50th cycle. The outstanding cycling stability is obtained upon 800 cycles with a large reversible capacity of 871 mAh g-1 and a negligible fading rate of 0.02% per cycle at a rate of 1.0 C, suggesting its promising prospects for the commercial success of high-performance Li-S batteries toward flexible electronic devices and energy storage equipment.

Keywords: flower-like MoS2; lithium-sulfur batteries; perovskite particle; polysulfide shuttling; redox kinetic.