Enhanced Electrochemical Performances of BiO/rGO Nanocomposite via Chemical Bonding as Anode Materials for Lithium Ion Batteries.

Bismuth oxide/reduced graphene oxide (termed BiO@rGO) nanocomposite has been facilely prepared by a solvothermal method via introducing chemical bonding that has been demonstrated by Raman and X-ray photoelectron spectroscopy spectra. Tremendous single-crystal BiO nanoparticles with an average size of ∼5 nm are anchored and uniformly dispersed on rGO sheets. Such a nanostructure results in enhanced electrochemical reversibility and cycling stability of BiO@rGO composite materials as anodes for lithium ion batteries in comparison with agglomerated bare BiO nanoparticles. The BiO@rGO anode material can deliver a high initial capacity of ∼900 mAh/g at 0.1C and shows excellent rate capability of ∼270 mAh/g at 10C rates (1C = 600 mA/g). After 100 electrochemical cycles at 1C, the BiO@rGO anode material retains a capacity of 347.3 mAh/g with corresponding capacity retention of 79%, which is significantly better than that of bare BiO material. The lithium ion diffusion coefficient during lithiation-delithiation of BiO@rGO nanocomposite has been evaluated to be around ∼10-10 cm/S. This work demonstrates the effects of chemical bonding between BiO nanoparticles and rGO substrate on enhanced electrochemical performances of BiO@rGO nanocomposite, which can be used as a promising anode alterative for superior lithium ion batteries.