CNTs@S cathode modified with a barrier layer of TiO₂-decorated reduced graphene oxide for lithium–sulfur batteries

In this work, reduced graphene oxide decorated with well-distributed TiO₂ nanoparticles is fabricated through one-step hydrothermal reaction to modify CNTs@S cathode as a barrier layer. Its three-dimensional interconnected layered structure can restrain the migration of polysulfides, as well as promote electrical and ionic conduction. The uniformly distributed TiO₂ nanoparticles on reduced graphene oxide surface also anchor the lithium polysulfides through chemical interaction, which benefits the cycle stability of the sulfur-containing cathode. As a result, the sulfur-containing cathode with the barrier layer reaches an initial reversible specific capacity of 1090.4 mAh g⁻¹ at 0.2C, with the capacity retention of 93.1% after 150 cycles and the coulombic efficiency above 99%.