Carbon@carbon double hollow spheres as efficient cathode host for high rate Li-S battery

Development of carbon materials for lithium-sulfur (Li-S) battery that can confine the sulfur species effectively while serving as a conductive matrix for high rate performance has attracted intense research interest. Herein, we report designing of a double hollow spherical carbon (C@C) by using RF resin coated SiO2 as an exo-template. The developed C@C/S cathode could host about 69.1 wt% of S and exhibits a high specific capacity of 1396 mAh g(-1) at 0.05 C corresponding to 83.5% of S utilization. Furthermore, the cathode could sustain a current rate of 5 C (8.4 A g(-1)) and still delivers a reasonable capacity of 320 mAh g(-1) with excellent electrochemical stability at this high rate with no apparent capacity fading for 100 cycles. The present results highlight the importance of morphological pre-design for developing advanced carbon materials as Li-S cathode host.