Trapping polysulfide on two-dimensional molybdenum disulfide for Li-S batteries through phase selection with optimized binding

Abstract

Introducing anchoring materials into cathodes for Li-S batteries has been demonstrated as an effective way to overcome the shuttle effect and enhance the cycling stability. In this work, the anchoring effects of 2H-MoS2 and 1T'-MoS2 monolayers for Li-S batteries were investigated by using density functional theory calculations. It was found that the binding energies of Li2Sx absorbed on 1T'-MoS2 monolayer are in the range of 0.31-2.94 eV, which is much higher than on the 2H-phase. The 1T'-MoS2 monolayer shows stronger trapping ability for Li2Sx than the 2H-MoS2 monolayer. The 1T'-MoS2 monolayer can be used as effective anchoring material in cathodes for Li-S batteries.