Sulfur nanosheets deposited on reduced graphene oxide enable excellent cycling life for lithium-sulfur battery

Abstract

A lithium-sulfur (Li–S) battery cathode composed of sulfur nanosheets and reduced graphene oxide (rGO) was successfully synthesized. During cycles, the sulfur nanosheets form a protective sulfur layer that acts as a barrier against the shuttle effect, attributed to physical confinement and spontaneous chemical reactions. Simultaneously, the pores within the nanosheets create pathways for lithium ions, ensuring efficient sulfur utilization even at high sulfur content levels of up to 89 %. This design enables the cathode to achieve a high discharge capacity of 1596.9 mAh g−1 at 0.1C and 1433.5 mAh g−1 at 0.5C during the first cycle. Furthermore, the capacity of a Li–S battery has been shown to maintain over 1200 h at 0.5C and 450 h at 1 C simply by adjusting the morphology of the sulfur source. This significant discovery not only offers a new research direction for Li–S batteries, but also has the potential to advance the application of Li–S batteries in various fields.