Lithium-sulfur batteries are considered to be one of the most promising candidates for next-generation "beyond lithium-ion" energystorage systems. However, the commercialization of lithium-sulfur batteries has been hindered by fast capacity fade caused by polysulfide shuttling problems, as well as by a limited volumetric energy density due to low sulfur loading. Here, porous Fe3O4 nanospheres have been employed as a sulfur host to address the polysulfide shuttling problem through chemical interactions. We have employed optical microscopy and cryogenic scanning transmission electron microscopy (cryo-STEM) with X-ray energy dispersive spectroscopy (XEDS) elemental mapping to study the inherent microstructure of an Fe3O4/S composite with 85% sulfur content. We observe well-faceted, micrometer-sized sulfur particles embedded in a network of the conductive Fe3O4 nanosphere host particles. Our Fe3O4/S composite shows high capacity and outstanding cycling stability. The initial areal capacity is 2.6 mAh cm(-2) and a high areal capacity of 2.2 mAh cm(-2) was retained after 150 cycles. We believe that both the embedding of sulfur, in a conductive Fe3O4 network, and the strong chemical interactions between Fe3O4 and polysulfides are responsible for the high capacity and high cycling stability of our Fe3O4 composite cathode. (C) 2018 The Electrochemical Society.