Novel flower-like hierarchical carbon sphere with multi-scale pores coated on PP separator for high-performance lithium-sulfur batteries

Lithium-sulfur (Li-S) battery is considered as the next-generation of cost-efficient rechargeable battery systems to fulfill clean energy transportation systems due to its remarkable high theoretical energy density. Nevertheless, capacity fading and poor cycling stability mostly caused by polysulfide shuttle and active sulfur materials loss play an obstacle role on large-scale viable commercialization. In this paper, a flower-like hierarchical carbon sphere (FHCS) is prepared and coated on commercialized PP separator for polysulfide trapper. This carbon sphere with multi-scale pores strongly absorbs the polysulfide, further tremendously enhances the cycling performances, and the conducted carbon sphere also acts as current collector for improving the conductivity of active materials. The results show the cell demonstrates an initial discharge specific capacity of up to 1427 mAh g−1 at 0.2C, and high reversible capacity of 730 mAh g−1 with degradation rate of only 0.061% per cycle after 500 cycles at 0.5C.