锂离子电池正极材料FePO_3(英文)

FePO_4 as a Positive Electrode Material for Lithium Secondary Batteries

通过控制溶液的pH值用FeCl3和Na3PO4溶液共沉淀法制备出了无定型FePO4.1.3H2O,通过成分析,热分析,X射线衍射和扫描电镜分析对材料进行了表征。该材料在0.2 mA.cm-2的电流密度下起始容量达到130mA.h.g-1同时具有良好的循环性能,表现出一个良好的锂离子电池候选材料。球磨可以提高材料的电化学性质,可能是因为其中活性成份含量提高的原因。当其加热到700℃成为晶态的FePO4时则容量变低,这种高温下容量的损失的机理可能是与高温下形成非活性相有关。

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℃.