A hierarchical composites constructed by ZIF-8 derived carbon core and Mn3O4/N-doped carbon shell as efficient polysulfide entrapment host for Li−S batteries

Abstract

Abstract Recent researches demonstrate that functional materials (such as heteroatom doped carbon and metal oxides) as sulfur host can chemically adsorb lithium polysulfides, thereby alleviating the shuttle effect of Li-S batteries (LSBs). Herein, a hierarchical core-shell nanocomposites are rationally designed for enhancing the cycle performance of the sulfur cathode, which is constructed by ZIF-8 derived carbon core and hierarchical Mn3O4/N-doped carbon shell (ZPC@HMn3O4/NC). The ZPC core with highly porous structure can provide sufficient space for sulfur loading and physical adsorption of the polysulfides during cycling. Moreover, the hierarchical Mn3O4/NC shell play a dual role in physical restricting and offering strong chemical adsorption of polysulfides. As a result, the ZPC@HMn3O4/NC as sulfur host exhibits superior electrochemical performance. Specifically, ZPC@Mn3O4-NPC/S cathode with 71.5\xa0wt% sulfur content shows an initial capacity of 1236\xa0mAh\xa0g−1 at 0.1\xa0C, an excellent rate capability of 430 mAh g−1 at 8 C and a long-term cycling performance of 301\xa0mAh\xa0g−1 after 1000 cycles at 5\xa0C.