Tubular NiCo2S4 hierarchical architectures as sulfur hosts for advanced rechargeable lithium sulfur batteries

Abstract

Tubular nickel and cobalt bimetal sulfides NiCo2S4 hierarchical architectures were fabricated by a facile solvothermal method and investigated electrochemically as sulfur hosts for lithium sulfur batteries compared to bare sulfur. The results indicated that the single/double-walled tubular NiCo2S4 could be tuned to assemble the hierarchical architectures consisting of the nanoparticles, their electrochemical performances as sulfur hosts for lithium sulfur batteries are exhibited differently with respect to the host morphology and even compared to those of bare sulfur as well. Comparatively, the double-walled tubular NiCo2S4 hierarchical architecture as sulfur host for lithium sulfur batteries delivers a higher initial specific capacity of as high as 1078.9 mAh g−1, and exhibits better cyclability and rate capability, which might be ascribed to even dispersion of sulfur over the electrically conductive double-walled tubular NiCo2S4 hierarchical architecture, thus facilitating the full utilization of sulfur and the fast redox reaction kinetics of lithium polysulfides. In a word, bimetal sulfide NiCo2S4 are promising as sulfur host for the industrial implementation of lithium sulfur batteries, dependent of its optimization on morphology and structure.