High-performance lithium storage in nitrogen-enriched carbon nanofiber webs derived from polypyrrole

Nitrogen-doped carbon nanofiber webs (N-CNFWs) are prepared by direct pyrolyzation of polypyrrole (PPy) nanofiber webs at 600 degrees C. The structure and morphology of N-CNFWs are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FTIR), Raman spectra and elemental analysis. Both the doped N content and the N existing type in carbon, change with the pyrolysis time. As anode material for lithium-ion battery, the N-CNFWs show high capacity and good rate capability. The reversible capacity is up to 668 mAh g(-1) at a current density of 0.1 A g(-1) and 238 mAh g(-1) at 5 A g(-1), which can be ascribed to the nanofiber structure and high nitrogen content. (c) 2013 Elsevier Ltd. All rights reserved.