Hollow Multi-Shelled Structural TiO2-x with Multiple Spatial Confinement for Long-Life Lithium-Sulfur Batteries.

TiO2-x with well-controlled hollow multi-shelled structures (HoMSs) were designed and synthesized, via a sequential templating approach (STA), to act as sulfur carrier materials. They were explored as physico-chemical encapsulation materials. Particularly, the sulfur cathode based on triple-shelled TiO2-x HoMSs delivered a specific capacity of 903 mAh g-1 with a capacity retention of 79 % at 0.5 C and a Coulombic efficiency of 97.5 % over 1000 cycles. The outstanding electrochemical performance is attributed to better spatial confinement and integrated conductivity of the intact triple-shell that combine the features of physico-chemical adsorption, short charge transfer path along with mechanical strength.