Lithium sulfur battery

In lithium ion batteries, Li ions move from the anode to the cathode during discharge and back when charging. Sulfur cathodes have much larger capacities than do the components in commercial lithium-ion batteries, but their long-term performance suffers due to diffusion of soluble polysulfides into the electrolyte. We performed first-principles molecular dynamics study and revealed the formation at high Li/S ratios of large, insolubleLi-S clusters that ultimately fuse into a network, and also predicts stabilization of soluble polysulfides by functionalized graphene-based materials incorporated into the cathode. The results provide fundamental understanding at the atomic level of the soluble polysulfides, and represent an important step towards further development of the Li/S batteries.See Phys. Rev. Appl. 2, 034004 (2014); ACS Energy Letters, 1, 481-489 (2016); J. Mater. Chem. A, 5, 1650-1657 (2017)