Hydrothermal synthesis of lithium iron phosphate cathodes

Hydrothermal methods have been successfully applied to the synthesis of lithium iron phosphates. Li3Fe2(PO4)(3) was synthesized by heating at 700 degreesC LiFePO4(OH), formed hydrothermally in an oxidizing environment. Crystalline LiFePO4 was formed in a direct hydrothermal reaction in just a few hours, and no impurities were detected. This result leads to the possibility of an easy scaleup to a commercial process. The samples were characterized by X-ray diffraction, thermogravimetric analysis and scanning electron microscopy. Both phosphates were tested as the cathode in lithium batteries and showed results comparable to those formed by conventional high-temperature synthesis. (C) 2001 Elsevier Science BN. All rights reserved.