Unveiling mechanisms of blocking polysulfides by carbon nanotubes

Lithium-sulfur (Li-S) batteries have been considered as a candidate to overcome the limits of Li-ion batteries. However, the polysulfide shuttle effect in Li-S batteries must be addressed before their practical application. A feasible solution to this problem is to insert a carbon nanotube (CNT) interlayer between the Li-S battery cathode and separator for encapsulating polysulfides . Although many CNT interlayers have been developed, how the CNT interlayer blocks polysulfides is still, to a large extent, unknown. In this paper, combined MD simulations and DFT calculations were used to elucidate the effects of CNT size, interspacing, and functional groups on polysulfide encapsulation. Our findings provide new design guidelines for Li-S battery CNT interlayers to optimize the battery performance.