A Functional TiO2-Coated Separator for High-Performance Li-S Batteries

The shuttle effect of polysulfides during a cycle severely limits the further development of lithium-sulfur (Li-S) batteries. Therefore, a functional separator coated with TiO2 was prepared. This separator chemically adsorbed polysulfides, which reduced the shuttle effect and improved the cycle stability and specific capacity during cycling. Moreover, the initial discharge capacity of the battery with a spherical TiO2-coated separator reached 1086 mAh g(-1) and after 100 cycles remained at 793 mAh with a rate of 0.1 C. The coulombic efficiency was kept at 99%, and the capacity attenuation of each cycle was only 0.26%, which showed good cycle stability.