Mildly reduced less defective graphene oxide/sulfur/carbon nanotube composite films for high-performance lithium–sulfur batteries

Abstract

The microstructures and properties of the carbonaceous matrices in the cathodes of lithium–sulfur (Li–S) batteries have strong effects on their performances. We prepared a ternary composite cathode of mildly reduced less defective graphene oxide (mrLGO), sulfur, and carbon nanotubes (CNTs) by filtration for Li–S batteries. This battery showed a high initial specific capacity of 1219 mA h g⁻¹ at 0.2 C and a stable specific capacity of around 1000 mA h g⁻¹ after 200 cycles with a coulombic efficiency of 99%. Its excellent performance is mainly attributed to the good conductivity and residual oxygen containing groups of mrLGO, and the three-dimensional (3D) framework constructed using mrLGO sheets and CNTs.