One-step ultrasonic spray route for rapid preparation of hollow Fe3O4/C microspheres anode for lithium-ion batteries.

One-step preparation of nanoparticles-assembled hollow Fe 3 O 4 /C microsphere composites was achieved by an energy-efficient and continuous ultrasonic spray pyrolysis process. Systemically characterizations by scanning and transmission electron microscopy, X-ray diffraction, and Raman spectroscopy suggest that the physical and structure properties are highly dependent on the pyrolytic temperature; the outer surface of the hollow Fe 3 O 4 /C products are actually built by mesoporous carbon nanosheets overlaying Fe 3 O 4 nanoparticles. Attributing to the synergistic effect of connected carbon layers and moderate hollow microsphere configuration with mesoporous nature, the optimal Fe 3 O 4 /C composites obtained at 800 °C deliver an initial specific discharge and charge capacity of 1236.0 and 1034.0 mAh g −1 with an initial coulombic efficiency of 83.65% at 0.1 A g −1 , and the specific capacity can recover to above 1030 mAh g −1 after suffering 100 cycles when the current density was reduced from 4 to 0.1 A g −1 . The present report may open up a promising opportunity to push forward application for next generation Li-ion batteries. [ABSTRACT FROM AUTHOR]