Monodispersed hollow carbon/Fe3O4 composite microspheres for high performance anode materials in lithium-ion batteries

Monodispersed carbon/Fe3O4 composite microspheres with hollow structures are prepared by heat treating monodispersed hollow poly(St/AN/DVB)/Fe3O4 microspheres synthesized through seeded polymerization and a wet chemical method. Monodispersed hollow carbon/Fe3O4 composite microspheres are characterized by optical microscopy, scanning electron microscopy, focused-ion beam scanning electron microscopy and transmission electron microscopy, X-ray diffraction. The electrodes containing the monodispersed hollow carbon/Fe3O4 composite microspheres exhibit an excellent cycling and rate capabilities with efficiency of 99% even after 100 cycles at high current rate. These results are because hollow structure and Fe3O4 nano-crystals introduced significantly affected the kinetics of lithium ions and improvement of low capacity of carbon used as LIBs anodes.

► Monodispersed hollow carbon/Fe3O4 microspheres exhibit excellent rate performance.
► Formation of Fe3O4 nano-crystals affects the shell thickness and surface morphologies.
► High reversible capacities can be remained at various current rates from 0.1 to 10C.
► The excellent cycling and rate performance can be attributed to the hollow structure.