Ultrathin SnS 2 nanosheets as robust polysulfides immobilizers for high performance lithium-sulfur batteries

Abstract Ultrathin SnS 2 nanosheets modified sulfur/carbon (S/C-SnS 2 ) composites were synthesized through a facile method by mixing sublimed sulfur, Ketjen Black and ultrathin SnS 2 nanosheets. The ultrathin SnS 2 nanosheets can provide remarkable binding strength, large surface area and fast charge transfer, therefore leading to favorable chemical interaction with polysulfides in Li-S batteries. Accompanied with the synergistic effects between physical confinement of porous carbon and chemical interactions of SnS 2 , S/C-SnS 2 composites with different mass ratio of ultrathin SnS 2 nanosheets and C show much improved electrochemical properties. Among them, S/C-SnS 2 composite with 10 wt% of ultrathin SnS 2 nanosheets and 75 wt% of sulfur maintains superior long term cycling capacities of 800 mAh g −1 at 0.5 C after 300 cycles and 540 mAh g −1 at 2 C after 700 cycles.