Facile complex-coprecipitation synthesis of mesoporous Fe3O4 nanocages and their high lithium storage capacity as anode material for lithium-ion batteries

Abstract

In this study, high-quality mesoporous Fe3O4 nanocages (MFONs) have been synthesized by a facile complex-coprecipitation method at 100°C with addition of triethanolamine and ethylene glycol. The as-prepared Fe3O4 nanocages possess a mesoporous structure and highly uniform dispersion. When used as an anode material for rechargeable lithium-ion batteries, MFONs anode shows high specific capacities and excellent cycling performance at high and low current rates. At a current density of 200mAg−1, the discharge specific capacities are 876mAhg−1 at the 2nd cycle and 830mAhg−1 at the 100th cycle. Even at the high current density of 1000mAg−1, MFONs anode still retains a stable capacity of 573mAhg−1 after 300 cycles. This superior electrochemical performance is attributed to the unique mesoporous cage-like structure and high specific surface area (133m2g−1) of MFONs, which may offer large electrode/electrolyte contact area for the electron conduction and Li+ storage. Furthermore, the good mechanical flexibility of the mesoporous nanocages can readily buffer the massive volume expansion/shrinkage associated with the reversible electrode reaction. These results indicate that MFONs can be used as a promising high-performance anode material for lithium-ion batteries.