▎ 摘　　要

NiO-SnO2/GNs ternary composites were synthesized by hydrothermal approach and subsequent calcination in nitrogen atmosphere. Structural characteristics of the composites were investigated by a series of physical measurements, such as X-ray diffraction measurement, scanning electron microscopy, and transmission electron microscopy. Results showed that NiO-SnO2 particles were distributed on graphene and had formed a well-ordered, sheet-like structure. The content of NiO was relatively small and distributed along the carbon substrate, which can improve the decomposition process of irreversible Li2O. Electrochemical performance measurements demonstrated that the discharge capacity of NiO-SnO2/GNs, unlike NiO-SnO2 materials, increased from 1022.2 mAh/g to 1212.9 mAh/g and maintained at 649.3 mAh/g after 50 cycles. The contribution of capacity during discharge progress can be explained by three parts: the reaction between SnO2 and Li, the reaction between NiO and Li, and the alloying process between Sn and Li. In addition to the catalytic characteristic from nickel-based oxides, the unique structure of graphene can buffer the volume change and prevent the aggregation of the active materials upon cycling to enhance the material performance. Furthermore, the high conductivity of graphene decreased the material internal resistance. (C) 2016 Elsevier B.V. All rights reserved.