Rational Fabrication of Nitrogen and Sulfur Codoped Carbon Nanotubes/MoS2 for High-Performance Lithium-Sulfur Batteries.

Abstract

Lithium-sulfur batteries are more promising and attractive than lithium-ion batteries owing to a higher charge-storage capacity. However, their commercial applications are hindered by an undesirable polysulfide shuttling effect during the cycling procedure. Herein, nitrogen and sulfur codoped carbon nanotubes intertwined with flower-like molybdenum disulfide (NSCNTs/MoS2 ) were synthesized by using a feasible hydrothermal method and used as effective lithium polysulfides (LiPSs) tamers. The NSCNTs/MoS2 had a strong hybrid structure with strong interfacial interactions for physical confinement, chemical adsorption, and electrocatalytic conversion of intermediate LiPSs during the charge-discharge process. The NSCNTs intensified the flexibility and constructed a conductive framework for rapid ion/electron transfer, whereas the electrocatalysis of MoS2 managed the sulfur reaction chemistry in two ways: it chemically immobilized LiPSs through Li-S bonds and kinetically sped up the sulfur redox reactions. Owing to these merits, the Li-S cell with a NSCNTs/MoS2 host and NSCNTs/MoS2 -coated separator (NSCNTs/MoS2 /S-NM) exhibited a high reversible capacity of 814 mAh g-1 at 1.0 C and long-lasting cycling durability with an ultralow capacity decay of 0.02 % per cycle over 1000 cycles. Accordingly, rationally integrating the concepts of physical immobilization, chemical capture, and electrocatalysis to establish a multifaced cell structure for the architecture of high-performance Li-S batteries is a significant strategy.