Synthesis and Electrochemical Properties of Nanocrystalline LiFePO4Obtained by Different Methods

Nanocrystalline powders were prepared at 660- in an Ar atmosphere using two different synthetic routes, solid-state and sol-gel. Both materials showed well-developed XRD patterns without any impurity peaks. Particles composed in the range of 200-300 nm from the solid-state method, and 50-100 nm from the sol-gel method, were confirmed through scanning electron microscopy and dynamic light scattering. The obtained by the sol-gel method offered a high discharge capacity (153 mAh/g) and stable discharge behavior, even at elevated temperatures (50 and ), whereas poor electrochemical performance was observed from the solid-state method. Rate capability studies for sol gel-derived ranged from 0.2 to 30 C, which revealed excellent retention over 70 cycles with a 99.9% capacity.