Coral-like interconnected carbon aerogel modified separator for advanced lithium-sulfur batteries

Abstract: Lithium-sulfur batteries (LiSBs) have attracted great interest owing to their ultrahigh theoretical capacity. However, the poor utilization of active substrate, caused by the shuttle effect of soluble polysulfide and poor electrochemical kinetics, hinders the commercial application of LiSBs. Herein, N-doping and ultrahigh surface area carbon aerogel in coral-like structure (NHCA) used as a modification of separator in LiSBs was successfully prepared by atmospheric pressure drying and activation subsequently. The introduction of NHCA not only block the shuttle effect of polysulfide with a similar effect of molecular sieve, but also built a low-resistance conductive network between the cathode and separator. After 200 cycles at 1 A/g, the capacity of cell with NHCA-7/Celgard was retained at 820 mAh/g, with just 0.13% decay per cycle. The research outcomes of this study provide a new insight for the interlayer modification of advanced LiSBs.