Synergistic coupling between Fe7S8-MoS2 heterostructure and few layers MoS2-embeded N-/P-doping carbon nanocapsule enables superior Li-S battery performances

Rechargeable Li-S batteries have attracted considerable interests because of their high theoretical energy density and cost-effectiveness. Nevertheless, the dissolution, shuttling and sluggish conversion of soluble lithium polysulfide intermediates seriously aggregates the cycle life and rate performances of batteries. In this work, a Fe7S8-MoS2 heterostructure decorated on few layers MoS2-embeded N-/P-doping carbon nanocapsule is for the first time developed as high efficient sulfur host for Li-S batteries. This structure offers a practical way to confine and catalyze the soluble lithium polysulfide. In particular, combining advantages with both coupling components, the Fe7S8-MoS2 heterostructure greatly enhances the adsorption abilities towards lithium polysulfide and accelerates their conversion kinetics. Besides, the few layers MoS2-embeded N-/P-doping carbon nanocapsule framework provides sufficient space and abundant adsorption sites to physically and chemically confine soluble lithium polysulfide, effectively suppressing their dissolution and shuttle effect. The synergistic coupling between the Fe7S8-MoS2 heterojunction catalyst and the delicately designed carbon architecture enables excellent rate capability and cycle performances for Li-S batteries. This work highlights the comprehensive material design matrix of dissimilar bandgaps sulfur hosts for future Li-S battery technologies.