Graphene nanosheet@spherical ordered mesoporous carbon/sulfur nanocomposites as cathode material for high-performance lithium-sulfur batteries

摘要

Owing to the high energy density and rich resource, Li-S batteries are now considered as a promising direction in energy storage. Nevertheless, the electrochemical properties of sulfur host materials have been limited by the large volume changes during cycles, the dissolution of polysulfides in an electrolyte, and the insulating properties of lithium polysulfides. Based on the above conclusions, a novel cathode material of graphene nanosheet@spherical ordered mesoporous carbon/sulfur nanocomposite (GNs@s-OMC/S) where s-OMC/S was wrapped by GNs has been synthesized in this article and delivers superior cycle stability. According to the tests, GNs@s-OMC/S provides a capacity of 1159 mAh g(-1) at a 0.4 C discharge rate. In addition, even at a high rate of 4 C, the discharge capacity of GNs@s-OMC/S can also remain 767 mAh g(-1), representing a fantastic rate performance and high specific capacity. It can be ensured that the narrow channels provided by s-OMC and the graphene entrapment with high conductivity enhance the electrochemical performance of the cathode. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.