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

Core-hell hollow TiO 2 @VP heterostructure sulfur host displays a favorable LiPS adsorption ability and excellent catalytic activity towards polysulfide conversion with a high specific capacity of ∼1430 mAh g −1 at 0.1 C, and an excellent rate capacity of ∼521 mAh g −1 at 5 C. Even at a very high sulfur loading of ∼7.5 mg cm −2 , the h-TiO 2 @VP/S cathode-based Li-S battery delivers an exceptional areal capacity of ∼7.13 mAh cm −2 . • Core-shell of hollow TiO 2 spheres decorated with VP nanosheets were developed. • The combination of excellent catalytic performance and strong adsorption properties for LiPS was investigated. • The h-TiO 2 @VP/S cathode presents high capacity and outstanding long-term stability. • Li-S battery can work well under ultrahigh sulfur loading of ∼7.4 mg cm −2 and low E/S of ∼5.1 µL mg −1 . 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-TiO 2 @VP) as an efficient sulfur host. The combination of strong chemical adsorption ability of hollow TiO 2 nanospheres and excellent LiPS conversion catalyst of VP nanosheets which help to suppress the shuttling effect. The theoretical calculation showed that the h-TiO 2 @VP-50 (ratio of 5:5) could deliver higher conductivity and better adsorption ability toward LiPS. In particular, the composite of h-TiO 2 @VP and sulfur (h-TiO 2 @VP/S) cathode reveals a high specific capacity of ∼1430 mAh g −1 at 0.1 C, and an excellent rate capacity of ∼521 mAh g −1 at 5 C. Even at a high sulfur loading of ∼7.5 mg cm −2 , the h-TiO 2 @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 alternation for the state-of-the-art Li-ion cell.