Layered carbide-derived carbon with hierarchically porous structure for high rate lithium-sulfur batteries

Practical applications of lithium-sulfur batteries require not only high specific capacities and long cycle life but also high rate performance. Herein, a layered carbide derived carbon (CDC) with hierarchically porous structure is designed and used as sulfur host for high rate lithium-sulfur batteries for the first time. In the layered CDC, sulfur was mainly infiltrated into the micropores and small mesopores, which could efficiently confine sulfur species and suppress polysulfides shuttling. At the same time, the layered structure and large mesopores would further shorten ion diffusion distance and buffer volume expansion. As a result, the layered CDC/sulfur composite with a sulfur loading of 50 wt.% delivered not only a high initial discharge capacity of 1229 mAh g(-1) at 0.5C, but also a superior reversible capacity of 621 mAh g(-1) at 5C. Especially, the high rate capability could also be achieved even at a higher sulfur loading (68 wt.%). This work suggests that porous carbon combined with layered structure and hierarchical pores could be used as effective matrix to host sulfur for high rate lithium-sulfur batteries. (C) 2015 Elsevier Ltd. All rights reserved.