Confined Sulfur in Microporous Carbon Renders Superior Cycling Stability in Li/S Batteries

© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim 1 wileyonlinelibrary.com state-of-the-art Li ion batteries fail to meet this host of requirements, as demonstrated by the performance of its fl agship chemistry LiCoO 2 . Despite its widespread implementation, LiCoO 2 is toxic, expensive (≈$20 kg −1 ), and typically characterized by mediocre capacity (≈150 mAh g −1 ) due to intrinsic limitations imposed by the inert intercalation hosts. [ 2–4 ] This latter limitation is expected to be broken only with cathode materials of the “conversionreaction” nature, [ 4 ] and elemental sulfur has been considered a promising candidate, due to its abundant distribution in the earth’s crust, commodity availability at $0.05 kg −1 , projected theoretical capacity of 1672 mAh g −1 , and low toxicity. [ 5–9 ]