Cobalt nanoparticles shielded in N-doped carbon nanotubes for high areal capacity Li-S batteries.

N-Doped carbon nanotubes with embedded cobalt nanoparticles (Co-NCNTs) were prepared by thermally annealing a mixture of ZIF-67 and dicyandiamide precursors. Because of the dual chemical affinity of Co and N to S species, Li-S batteries with a Co-NCNT modified separator revealed enhanced redox kinetics of lithium polysulfide conversion and achieved a high areal capacity of 3.73 mA h cm-2 after 100 cycles at 0.1C at a sulfur loading of 4.3 mg cm-2.