Encapsulating chalcogens as the rate accelerator into MoS2 with expanded interlayer spacing to boost the capacity and cyclic stability of Li–S batteries

Abstract

Abstract In this work, we have demonstrated the successful incorporation of selenium (Se)/tellurium (Te) into the covalently functionalized MoS2 (B-M) nanosheets as a host using a facile solvothermal method. The chalcogen-loaded composites (Se/Te@B-M-C) are characterized by various spectroscopic and microscopic analyses. These experiments prove that the amorphous Se/Te additive is homogeneously distributed over the MoS2 nanosheets with an expanded interlayer distance of ∼10 Å. The fabricated Li–S batteries composed of the Se/Te@B-M-C cathodes exhibit superior electrochemical performances when compared to that of the pristine chalcogens and bare host. The improved charge storage characteristics of these hybrids are attributed to the uniform distribution of chalcogens as the rate accelerators and the formation of a protective solid-electrolyte interphase layer over composites. The present study demonstrates that the structurally-engineered MoS2-based composites with evenly distributed amorphous Se (or Te) chalcogens as accelerators are potential candidates for next-generation high-performance lithium–sulfur batteries with high capacity and excellent cycle stability.