摘要
Lithium-sulfur batteries have attracted increasing attention because of their high theoretical capadty. Using sulfur/carbon composites as the cathode materials has been demonstrated as an effective strategy to optimize sulfur utilization and enhance cycle stability as well. In this work hollow-in-hollow carbon spheres with hollow foam-like cores （HCSF@C） are prepared to improve both capability and cycling stability of lithium-sulfur batteries. With high surface area and large pore volumes, the loading of sulfur in HCSF@C reaches up to 70 wt.%. In the resulting S/HCSF@C composites, the outer carbon shell serves as an effective protection layer to trap the soluble polysulfide intermediates derived from the inner component. Consequently, the S/HCSF@C cathode retains a high capacity of 780 mAh/g after 300 cycles at a high charge/discharge rate of 1 A/g.
基金
We thank the National Basic Research Program of China （Nos. 2011CB932403 and 2015CB932300） and the National Natural Science Foundation of China （Nos. 21301144, 21390390, 21131005, 21333008, and 21420102001） for financial support.
