Design and Synthesis of Bubble-Nanorod-Structured Fe2O3-Carbon Nanofibers as Advanced Anode Material for Li-Ion Batteries

A structure denoted as a "bubble-nanorod composite" is synthesized-by introducing the Kirkendall effect into the electrospinning method. Bubble-nanorod-structured Fe2O3-C composite nanofibers, which are composed of nanosized hollow Fe2O3 spheres uniformly dispersed in an amorphous Carbon Matrix, are synthesized as the target material. Post-treatment of the electrospun precursor nanofibers at 500 degrees C under 10% H-2/Ar mixture gas atmosphere produces amorphous FeOx-carbon composite nanofibers. Post-treatment of the FeOx-carbon composite nanofibers at 300 degrees C under air atmosphere produces the bubble-nanorod-structured Fe2O3-C composite nanofibers. The solid Fe nanocrystals formed by the reduction of FeOx are converted into hollow Fe2O3 nanospheres during the further heating process by the well-known Kirkendall diffusion process: The discharge capacities of the bubble-nanorod-structured,Fe2O3-C composite nanofibers and hollow bare Fe2O3 nanofibers for the 300th cycles at a current density of 1.0 A g(-1) are 812 and 285 mA h g(-1), respectively,