Synthesis and Characterization of Amorphous 3Fe[sub 2]O[sub 3]⋅2P[sub 2]O[sub 5]⋅10H[sub 2]O and Its Electrode Performance in Lithium Batteries

Amorphous was prepared by oxidation of iron(II) phosphate, obtained by spontaneous precipitation from iron(II) and phosphate aqueous solutions, by heating in air at 100°C. The material was characterized by thermal analysis, Mössbauer spectroscopy, X-ray powder diffraction, and scanning electron micrograph analysis. The material, tested as cathode in a nonaqueous lithium cell, exhibited a specific capacity of about 140 at a current density of 25 The utilization was reduced to about 76% by a tenfold increase of the discharge current. It showed an excellent cyclability. More than 1000 cycles were performed at about 50% of depth of discharge, with a capacity fade lower than 0.025%.