Facile synthesis of graphene-molybdenum dioxide and its lithium storage properties

Graphene-molybdenum dioxide composites in several ratios have been prepared through a facile synthesis method. Depending on the ratio, the as synthesized composites have either 2-dimensional graphene sheets with MoO ₂ particles anchored to them or a clustered agglomerate morphology. The composites have been characterised using Raman spectroscopy, X-ray diffraction, and electron diffraction to confirm the monoclinic MoO ₂ phase that is present. Lithium storage properties of the as-synthesised samples were tested in a coin-type half cell assembly to determine the relationship between the ratio and the electrochemical performance. The sample with highest amount of MoO ₂ (78 wt%) displayed the most promising lithium storage properties, with stable cycling performance at 0.2 A g ^-1 that shows negligible capacity loss over 50 cycles, retaining a capacity of 640 mA h g ^-1. The rate capabilities were also tested, and show a capacity of 380 mA h g ^-1 at 2.0 A g ^-1, which is comparable to the theoretical capacity of graphite and previously reported work on similar materials. © 2012 The Royal Society of Chemistry.