A metal organic foam-derived zinc cobalt sulfide with improved binding energies towards polysulfides for lithium–sulfur batteries

Abstract The shuttle effect of polysulfides is a serious issue for lithium–sulfur (Li–S) batteries, because it leads to rapid capacity decay. Herein, we present a metal organic foam-derived ZnCo2S4 that is capable of forming polar bonds with soluble polysulfides and improving the binding force to suppress the shuttle effect. The ZnCo2S4 also has a smaller Li ion diffusion barrier energy than ZnCo2O4. ZnCo2S4 grown on conductive carbon cloth facilitates fast electron transfer, while its hierarchical structure accommodates the volumetric expansion of sulfur in Li–S batteries. The ZnCo2S4/S cathodes exhibit a stable capacity of 833 mAh g−1 after 100 cycles at 0.1C and a high Coulombic efficiency of 99.9%, along with a high rate-performance after repeated tests; these features indicate a good potential for energy storage applications.