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Hydrothermal assembly of MnO-graphene core-shell nanowires with superior anode performance

Xiao, Zhihua, Ning, Guoqing, Ma, Xinlong, Zhao, Lei, Yu, Yintao, Wang, Haibin
Carbon 2019 v.142 pp. 461-467
anodes, batteries, electric potential, electrochemistry, graphene, graphene oxide, manganese carbonate, manganese oxides, nanowires, redox reactions
Wide application of high capacity anode materials for Li ion batteries (LIBs) is hindered by their structural instability. Assembling graphene and high capacity nanostructures with tight interaction is highly desirable for obtaining high performance anode materials. Here, we report a novel hydrothermal synthesis of homogeneous graphene-wrapped MnO nanowires. MnCO3 anchors formed by the redox reaction between graphene oxide (GO) and MnOOH have helped to assemble the core-shell structured nanowires. With an optimized graphene amount, the graphene-wrapped MnO nanowires exhibit high reversible capacities at a low voltage platform ∼1 V (1185 mAh g−1 at 50 mA g−1), excellent rate performance (884 mAh g−1 at 500 mA g−1 and 508 mAh g−1 at 3 A g−1), high initial coulombic efficiency (86.3%), and long-term cyclic stability (undiminished after 500 cycles at 1 A g−1). These remarkable electrochemical performances in LIBs are significantly associated with the special core-shell conductive framework. Our results show that the highly reactive groups in GO can be used to in-situ assemble graphene-coated nanostructures, and that the MnO-graphene core-shell nanowires are promising anode candidate for LIBs.