Enhanced Electrochemical Performances of Bi₂O₃/rGO Nanocomposite via Chemical Bonding as Anode Materials for Lithium Ion Batteries

Abstract

Bismuth oxide/reduced graphene oxide (termed Bi₂O₃@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 Bi₂O₃ 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 Bi₂O₃@rGO composite materials as anodes for lithium ion batteries in comparison with agglomerated bare Bi₂O₃ nanoparticles. The Bi₂O₃@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 Bi₂O₃@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 Bi₂O₃ material. The lithium ion diffusion coefficient during lithiation-delithiation of Bi₂O₃@rGO nanocomposite has been evaluated to be around ∼10^-15-10^-16 cm²/S. This work demonstrates the effects of chemical bonding between Bi₂O₃ nanoparticles and rGO substrate on enhanced electrochemical performances of Bi₂O₃@rGO nanocomposite, which can be used as a promising anode alterative for superior lithium ion batteries.