Mesoporous Amorphous FePO4 Nanospheres as High-Performance Cathode Material for Sodium-Ion Batteries

FePO4 nanospheres are synthesized successfully through a simple chemically induced precipitation method. The nanospheres present a mesoporous amorphous structure. Electrochemical experiments show that the FePO4/C electrode demonstrates a high initial discharging capacity of 151 mAh g(-1) at 20 mA g(-1), stable cyclablilty (94% capacity retention ratio over 160 cycles), as well as high rate capability (44 mAh g(-1) at 1000 mA g(-1)) for Na-ion storage. The superior electrochemical performance of the FePO4/C nanocomposite is due to its particular mesoporous amorphous structure and close contact with the carbon framework, which significantly improve the ionic and electronic transport and intercalation kinetics of Na ions.