Long term cycling studies of electrospun TiO 2 nanostructures and their composites with MWCNTs for rechargeable Li-ion batteries

Abstract

Nanofiber- and rice grain-shaped TiO 2 nanostructures and their composites with functionalized multiwalled carbon nanotubes were fabricated by electrospinning and subsequent sintering process for applications in Lithium ion batteries. The fabricated nanostructures were characterized by X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, scanning-and transmission electron microscopy and surface area measurements. All nanostructured materials showed average discharge-charge plateaux of 1.75 to 1.95V. The nanofibrous- and rice grain-shaped TiO 2 nanomaterials showed stable performances of 136 (± 3) mAh g -1 and 140 (± 3) mAh g -1, respectively, at the end of 800 cycles in the cycling range of 1.0-2.8 V vs. Li at a current rate of 150 mA g -1. TiO 2-CNT (4 wt.%) composites showed a slightly lower capacity value but better capacity retention (8% capacity loss between 10-800 cycles). We believe that the present long term cycling materials would have wide interests in lithium ion batteries research. © 2012 The Royal Society of Chemistry.