Synthesis and characterization of amorphous 3Fe(2)O(3)center dot 2P(2)O(5)center dot 10H(2)O and its electrode performance in lithium batteries

Amorphous 3Fe(2)O(3). 2P(2)O(5). 10H(2)O was prepared by oxidation of iron (II) phosphate, obtained by spontaneous precipitation from iron(II) and pho sphate aqueous solutions, by hearing in air at 100 degreesC. The material w as characterized by thermal analysis, Mossbauer spectroscopy, X-ray powder diffraction, and scanning electron micrograph analysis. The material, teste d as cathode in a nonaqueous lithium cell, exhibited a specific capacity of about 140 mAh g(-1) at a cur-rent density of 25 mA g(-1). 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 a bout 50% of depth of discharge, with a capacity fade lower than 0.025%. (C) 2001 The Electrochemical Society.