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

- Porous N-doped yolk-shell hollow carbon sphere (N-YSHCS) was synthesized.
- Graphene was further wrapped on the surface of N-YSHCS (rGO/N-YSHCS).
- The shuttle effect of polysulfides can be suppressed effectively by the unique microstructures.
- The synthesized rGO/N-YSHCS/S electrode exhibits a high reversible capacity of 800 mAh g−1 at 0.2 C after 100 cycles.
- The rGO/N-YSHCS/S electrode shows good high-rate performance (636 mAh g−1 at 1 C and 540 mAh g−1 at 2 C).

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 (800 mAh g−1 at 0.2 C after 100 cycles) and good high-rate capability (636 mAh g−1 at 1 C and 540 mAh g−1 at 2 C).

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