Amorphous hydrated iron (III) phosphate nanoparticles with average particle size of 80 nm were synthesized by a facile coprecipitation method at ambient temperature. The obtained sample was characterized by X-ray powder diffraction (XRD), thermogravimetrical analysis (TGA), and scanning electron microscopy (SEM). The electrochemical performances of the samples as cathode active materials were investigated in the 3.8-2.0 V range at a current density of 0.4 mA cm(-2). The results show that the obtained discharge capacity was improved for amorphous FePO(4)(.)2H(2)O. (C) 2004 Elsevier B.V. All rights reserved.