Facile solvothermal synthesis of mesoporous manganese ferrite (MnFe 2 O 4 ) microspheres as anode materials for lithium-ion batteries

We report the synthesis and characterization of the mesoporous manganese ferrite (MnFe 2 O 4 ) microspheres as anode materials for Li-ion batteries. MnFe 2 O 4 microspheres were synthesized by a facile solvothermal method using Mn(CH 3 COO) 2 and FeCl 3 as metal precursors in the presence of CH 3 COOK, CH 3 COOC 2 H 5, and HOCH 2 CH 2 OH. The samples were characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, nitrogen adsorption, thermal gravimetric, X-ray photoelectron spectroscopy, temperature programmed reduction, and temperature programmed oxidation. The synthesized mesoporous MnFe 2 O 4 microspheres composed of nanoparticles (10–30 nm) were 100–500 nm in diameter and had surface areas between 60.2 and 86.8 m 2 g −1, depending on the CH 3 COOK amounts added in the preparation. After calcined at 600 °C, MnFe 2 O 4 was decomposed to Mn 2 O 3 and Fe 2 O 3 mixture. The mesoporous MnFe 2 O 4 microspheres calcined at 400 °C showed a capacity of 712.2 mA h g −1 at 0.2 C and 552.2 mA h g −1 at 0.8 C after 50 cycles, and an average capacity fading rate of around 0.28%/cycle and 0.48%/cycle, much better than those of the samples without calcination and calcined at 600 °C. The work would be helpful in the fabrication of binary metal oxide anode materials for Li-ion batteries.