Monday, 10 October 2022
The Lithium-sulfur (Li-S) battery is one of the most promising future electrochemical energy storage systems owing to the intrinsic advantages of sulfur such as its high energy density, low cost, and innocuous nature. For several decades, many research teams have tried to develop high performance Li-S batteries. Recently, various approaches for high sulfur loading have been demonstrated to achieve high energy density Li-S batteries. Many types of porous carbon materials (e.g., graphene, mesoporous carbons, hollow carbon spheres, and carbon nanotubes) have been used as a sulfur host. In many cases, however, the large-scale implementation to Li-S batteries has been discouraged due to the non-scalable synthesis process of these carbon materials. To improve the energy density of a sulfur cathode, we demonstrate a dual-layer sulfur cathode composed of a S-filled carbon electrode and a sulfur deposit film. First, a sulfur electrode was fabricated by uniformly embedding sulfur within the porous network of a carbon film. Then, an ultra-thin sulfur layer was constructed on the surface of the sulfur electrode through physical vapor deposition (PVD) of elemental sulfur