Double Interlayers to Improve Cycle Performance for Li-S Batteries by Using Multiwall Carbon Nanotubes/Reduced Graphene Oxide

A novel multiwall carbon nanotube (MWCNTs) and reduced graphene oxide (RGO) as double interlayers approach is used to prepare lithium-sulfur (Li-S) battery which is first proposed, and the battery is significantly enhanced on both the specific capacity and cycle stability. The cell with double interlayers shows a discharge capacity of 1224 mAh g^-1 at a current rate of 0.2 C and presents a capacity of 854 mAh g^-1 after 100 cycles. When tested at 0.5 C, the sulfur electrode exhibited a high capacity of 689 mAh g^-1 after 350 cycles. At a higher current rate of 1 C, the cell delivered good cyclic performance and retained a capacity of 611 mAh g^-1 after 350 cycles with a Coulombic efficiency above 98% during cycling, and the capacity decay was only 0.09% per cycle. This result presents excellent electrochemical properties, and the study with a simple synthesis process provides a potential research of commercial production of Li-S battery.