Facile synthesis and electrochemical properties of Fe3O4 hexahedra for Li-ion battery anode

• Hexahedral and octahedral Fe3O4 samples are synthesized via a facile hydrothermal method.
• Fe3O4 hexahedra exhibit high discharge capacity, good rate capability and cyclic stability.
• The superior property is due to the small size, large surface area and good structure stability.

Hexahedral and octahedral magnetite (Fe3O4) samples have been successfully synthesized with a facile hydrothermal technique without any surfactants or templates. The electrochemical properties of the as-prepared samples have been investigated as advanced anode materials for Li-ion battery. It is found that Fe3O4 hexahedra display much higher specific capacitance and better cycle stability than those of Fe3O4 octahedra. Specifically, Fe3O4 hexahedra exhibit a high initial discharge capacitance of 1303.7 mAh g−1 at 100 mA g−1 and it remains stable after 40 cycles. The superiority of the electrochemical performance of Fe3O4 hexahedra may be attributed to the smaller particle size, the larger surface areas and the better structure durability.