Facile solvothermal synthesis of mesoporous manganese ferrite (MnFe_2O_4) microspheres as anode materials for lithium-ion batteries

摘要

We report the synthesis and characterization of the mesoporous manganese ferrite (MnFe_2O_4) microspheres as anode materials for Li-ion batteries. MnFe_2O_4 microspheres were synthesized by a facile solvothermal method using Mn(CH_3COO)2 and FeCl_3 as metal precursors in the presence of CH_3COOK, CH_3COOC_2H_5, and HOCH2CH2OH. 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_2O_4 microspheres composed of nanoparticles (10-30nm) were 100-500nm in diameter and had surface areas between 60.2 and 86.8m~2g~(~(-1)), depending on the CH_3COOK amounts added in the preparation. After calcined at 600°C, MnFe_2O_4 was decomposed to Mn_2O_3 and Fe_2O_3 mixture. The mesoporous MnFe_2O_4 microspheres calcined at 400°C showed a capacity of 712.2mAhg~(-1) at 0.2C and 552.2mAhg~(-1) at 0.8C after 50cycles, 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.