Free-standing and flexible sulfur/MWCNT composite electrodes for Li-S batteries

Different weight ratios of sulfur (S) and multi-walled carbon nanotubes (MWCNTs)-based composite electrodes were prepared and studied for lithium-sulfur (Li-S) batteries. The morphological, microstructural, thermal and electrochemical properties of the composite electrodes were analyzed. TG curves indicated high thermal stability, which confirmed the strong bonding between sulfur and carbon host. It was found from electrochemical studies that the equal weight ratio of S and MWCNT (S2) composite electrode led to high electrochemical performances compared to other composite electrodes. It delivered an initial discharge capacity of 1414 mAh/g at 0.1C and also even at high current density, i.e., 413 mAh/g at 3C. Moreover, it achieved high capacity retention of 67% at 0.1C on the 100th cycle.