Nb2O5 hollow nanospheres as anode material for enhanced performance in lithium ion batteries

Nb2O5 hollow nanospheres of average diameter ca. similar to 29 nm and hollow cavity size ca. 17 nm were synthesized using polymeric micelles with core-shell-corona architecture under mild conditions. The hollow particles were thoroughly characterized by transmission electron microscope (TEM), X-ray diffraction (XRD), infrared spectroscopy (FTIR), thermal (TG/DTA) and nitrogen adsorption analyses. Thus obtained Nb2O5 hollow nanospheres were investigated as anode materials for lithium ion rechargeable batteries for the first time. The nanostructured electrode delivers high capacity of 172 mAh g(-1) after 250 cycles of charge/discharge at a rate of 0.5 C. More importantly, the hollow particles based electrodes maintains the structural integrity and excellent cycling stability even after exposing to high current density 6.25 A g(-1). The enhanced electrochemical behavior is ascribed to hollow cavity coupled with nanosized Nb2O5 shell domain that facilitates fast lithium intercalation/deintercalation kinetics. (C) 2012 Elsevier Ltd. All rights reserved.