Sulfur Core Shell Structured 4 Cathode for Li S Batteries

12 density as high as 2600 Wh kg , 13 promising a revolutionary advantage as 14 the next-generation energy storage system. 15 However, the realization of practical appli16 cation is still hindered by the low capacity 17 release of S and the severe capacity fading 18 over cycling. 4 The low sulfur utilization 19 is generally caused by the insulating nature 20 of S (5 10 28 S m ), while the poor cycle 21 stability is mainly due to the high dissolubil22 ity of the reaction intermediates of lithium 23 polysulfides (Li2Sx, 4 < x e 8). 5 7 24 In order to overcome the hurdles in Li S 25 battery technology, various approaches 26 have been proposed to enhance the actual 27 capacity and the cycle stability of the sulfur 28 cathode. 18 Among them, themost widely 29 used method is to compose sulfur with 30 various carbon matrices, which can interact 31 with various atoms, ions, molecules, or even