TiO2-coated sulfur-carbon nanocomposite cathode for lithium-sulfur batteries

Abstract

TiO2-coated sulfur-acetylene black composite with a core-shell structure is synthesized via a simple process and investigated as a cathode for the lithium-sulfur batteries. The composite nanoparticle sizes are in the range of 50–100 nm, and the thickness of TiO2 shell is about 10–50 nm. The composites can greatly slow down the dissolution of lithium polysulfide and stabilize the structure during the charge and discharge process to achieve good long cycle and rate performances. After 500 cycles at a current density of 200 mA g−1, it still delivers a reversible capacity of 312.8 mAh g−1. And the nanocomposite can still remain a specific capacity of 625.4 mAh g−1 with the current density of 1000 mA g−1.