N-doped yolk-shell hollow carbon sphere wrapped with graphene as sulfur host for high-performance lithium-sulfur batteries

Abstract

N-doped yolk-shell hollow carbon sphere wrapped with reduced graphene oxide (rGO/N-YSHCS) is designed and fabricated as sulfur host for lithium-sulfur batteries. The shuttle effect of polysulfides can be suppressed effectively by the porous yolk-shell structure, graphene layer and N-doping. A good conductivity network is provided for electron transportation through the graphene layer coupled with the unique yolk-shell carbon matrix. Such unique structure offers the synthesized rGO/N-YSHCS/S electrode with a high reversible capacity (800mAhg−1 at 0.2 C after 100 cycles) and good high-rate capability (636mAhg−1 at 1 C and 540mAhg−1 at 2 C).