In situ synthesis of α-MoO3/graphene composites as anode materials for lithium ion battery

The α-MoO3/graphene composites (MoO3/G) were prepared via an in situ hydrothermal synthesis. The composites were characterized using various characterization techniques including powder X-ray diffraction, transmission electron microscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, and the electrochemical performance test. The results show that these MoO3/G composites exhibit high capacity and good cycle stability when used as the lithium-ion battery anode. Among all the samples, the MoO3/G-27 reveals the best electrochemical performance with an initial charge capacity of 977.7 mAh g−1 at a current density of 50 mA g−1, the first coulombic efficiency of 69.5%. After eighty cycles the electrode still maintains a capacity of 869.2 mAh g−1, giving high capacity retention of 88.9%. The good electrochemical performance of the composite anode is close related to its structure, in which the MoO3 nanobelts are not only homogeneously anchored on the surface but also embedded in the interlayer of the graphene sheets; hence the volume change and aggregation of the MoO3 nanobelts during lithium ion insertion/extraction process can be effectively hindered. On the other hand, graphene itself is an electronic conductor; the graphene and MoO3 nanobelts connect closely, which offers large electrode/electrolyte contacting area, short path length for Li+ transporting during lithium insertion and extraction.