关键词: 磷酸铁;正电子材料;锂电池

Abstract: Amorphous hydrated iron (Ⅲ) phosphate was prepared by spontaneous precipitation from aqueous solution of FeCl3 and Na3PO4 under control pH. The material was characterized by chemical analysis, thermal analysis, X-ray diffraction and scanning electron microscopy. The as prepared amorphous FePO4·1.3 H2O which delivered an initial capacity of up to 130mA·h ·g-1 at a current density of 0.2mA·cm-2 with good rechargeability, appears to be a promising candidate to positive electrode materials for lithium batteries. However, the crystalline hexagonal FePO4 which was obtained by heating the amorphous hydrate at 700℃ exhibits a lower capacity. Ball-milling could improve the electrochemical performance of the products due to more active materials content. The loss of capacity for materials formed at high temperature could be related to the formation of inactive phases of Fe3PO at 500℃ and Fe3P2.93O19.17 at 700℃.