Mingqi Chen1 Jitong Wang1 Donghui Long1 Yankai Pan1

1, State Key Laboratory of Chemical Engineering, Shanghai, Shanghai, China

Commercial application of Li-S battery is hampered by a series of complicated problems: (1) low active materials utilization and limited rate capability because of insulating nature of sulfur and its discharge product lithium sulfide(Li2S); (2) rapid capacity decay caused by dissolution and shuttle of intermediate products (Li2Sn, 2<n<8). Herein, we fabricated a novel carbon as the host for sulfur cathode for effective trapping of polysulfides. The novel nanostructure has the following characteristics: (1) the interior void space for higher sulfur-loading and relieving sulfur expansion; (2) the partially mesoporous shell allow fast ion transportation and thus a superior rate capability; (3) the outermost surface of hollow carbon nanosphere cluster (HCNC)with inadequate pore structure enable minimized lithium polysulfide dissolution during long cycle; (4) the agglomerate primary hollow nanosphere enable a high tapped density; and (5) the integral conductive carbon framework facilitate good electrons transfer. Due to the unique architecture of HCNC with good electrical conductivity, large void space, radialized mesoporous pathway, and outmost compacted carbon layer, they could deliver a high initial capacity of 1302 mA h g-1 at 0.2C with a reversible capacity of 803 mA h g-1 after 500 cycles. The sulfur cathode demonstrated a good rate capability with 721 mA h g-1 at 5C. Optimization and integration of different pore structures and morphologies can be the effective way for future development of high-rate and long-cycle Li–S batteries.