Nanostructured Antimony/carbon Composite Fibers as Anode Material for Lithium-ion Battery

Antimony/carbon (Sb/C) composite fibers with Sb nanoparticles uniformly dispersed in carbon matrix have been successfully fabricated by a facile spinning approach and the subsequent calcination in argon flux. As the anode materials of lithium-ion battery, experimental results reveal that the increase of Sb concentration enhanced the lithium-ion storage capacity and worsened the cycling performance. Carbon matrix could efficiently buffer the volume change and maintain the integrity of electrode during the lithiation/delithiation, improving the cycling capability. Among the Sb/C composite fibers, the sample (Sb5) with appropriate carbon content of ca. 50.1 wt% achieves a reversible capacity of 315.9 mAh g(-1) after 100 cycles at a current density of 100 mA g(-1) and the capacities of 464.4, 395.4, 328, 246.2 and 149.8 mAh g(-1) at 100, 200, 400, 800 and 1600 mA g(-1), respectively. Electrochemical impedance spectroscopy (EIS) results indicate that Sb5 shows more superior charge transfer rate and Li-ion diffusion ability than the samples with high Sb concentration (Sb6) or carbon concentration (Sb4), finally resulting in better capacity retention and rate performance. (C) 2014 Elsevier Ltd. All rights reserved.