polysulfide host in lithium–sulfur batteries

The high specific capacity and energy density of lithium–sulfur batteries have attracted strong considerations on their fundamental mechanism and energy applications. However, polysulfide shuttle is still the key issue that impedes the development of Li–S batteries. Exploring nanocrystal hosts for polysulfide immobilization and conversion is a promising way. In this contribution, we have investigated well-dispersed Co 9 S 8 nanocrystals grown on graphene oxide (GO) nanosheets with different degrees of dispersion as cathode host materials for Li–S batteries. The Co 9 S 8 -GO composite with 1 wt% GO (GCS1) has an average crystal size of 76 nm and shows the strongest adsorption capability toward lithium polysulfides. When used as the host material for the cathode of Li–S batteries, the GCS1-sulfur composite exhibits an initial specific capacity of ~10 0 0 mAh g −1 at 0.5 C and shows an average decay rate of 0.11% for 500 cycles. This work on the dispersion control of Co 9 S 8 nanocrystals may inspire more investigations on well-dispersed nanocrystal based hosts for Li–S batteries. © 2020 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.