Core-shell hollow nanostructures as highly efficient polysulfide conversion and adsorption cathode for shuttle-free lithium-sulfur batteries

Lithium-sulfur (Li-S) batteries are disclosed as prospective alternatives for next-generation energy storage technologies, due to their high theoretical energy density and cost-effectiveness. However, the shuttle effect and sluggish conversion reaction of polysulfide (LiPS) inhibit them from commercial application. To overcome these challenges, we anticipated a novel strategy to rational design a hollow titanium oxide nanosphere that is decorated with vanadium phosphide nanosheets (h-TiO2@VP) as an efficient sulfur host. The combination of strong chemical adsorption ability of hollow TiO2 nanospheres and excellent LiPS conversion catalyst of VP nanosheets which help to suppress the shuttling effect. The theoretical calculation showed that the h-TiO2@VP-50 (ratio of 5:5) could deliver higher conductivity and better adsorption ability toward LiPS. In particular, the composite of h-TiO2@VP and sulfur (h-TiO2@VP/S) cathode reveals a high specific capacity of-1430 mAh g-1 at 0.1C, and an excellent rate capacity of-521 mAh g-1 at 5C. Even at a high sulfur loading of -7.5 mg cm-2, the h-TiO2@VP/S cathode-based Li-S battery delivers an exceptional areal capacity of -7.13 mAh cm-2. This study opens a new door for designing the highly efficient Li-S battery cathode which can be a promising alter-nation for the state-of-the-art Li-ion cell.