Fabrication of a novel TiO2/S composite cathode for high performance lithium-sulfur batteries

摘要

Sulfur is an attractive cathode material with a high specific capacity of 1675 mA h g-1, but its rapid capacity decay due to polysulfide dissociation presents a significant technical challenge. Here, we present the fabrication of a TiO/S composite cathode by encapsulating elemental sulfur into TiO nanotube hosts for high performance lithium-sulfur batteries. A high capacity of 913 mA h g-1 has been achieved at a rate of 0.2C in the initial cycle for the TiO/S composite cathode with a sulfur content of 65 wt% and the reversible capacity remains as high as 851 mA h g-1 after 100 cycles. The improvements of electrochemical performances were attributed to the good dispersion of sulfur in the TiO nanotubes and the excellent adsorbing effect on polysulfides of TiO.