ZnO/carbon nanotube/reduced graphene oxide composite film as an effective interlayer for lithium/sulfur batteries

The application of lithium/sulfur (Li/S) batteries is negatively affected by the insulation of sulfur and large volumetric change during the cycles as well as the polysulfides dissolution. To solve the above problems, we fabricated a composite interlayer for Li/S batteries using ZnO nanocrystals anchored on connected carbon nanotube and graphene. The preparation of ZnO/carbon nanotube/reduced graphene oxide (ZnO/CNT/RGO) composite film was inspired from the combination of a one-step sol-gel synthetic technique and vacuum-assisted filtration. The ZnO/CNT/RGO interlayer showed effective adsorption of polysulfides during diffusion experiments. This ZnO/CNT/RGO interlayer can efficiently increase sulfur utilization by immobilizing soluble intermediate polysulfides. When used as a composite interlayer in Li/S batteries, an impressive high capacity of 768 mAh g −1 at 0.2C was achieved after 150 cycles and improved rate performance of 597 mAh g −1 at 2C was obtained. This study offers a facile method to improve the electrochemical performance of the Li/S batteries.