改进的固相法制备磷酸铁锂电池材料

采用改进的固相反应法(MSR)，制得了粒子微细、粒径分布窄的LiFePO4和Li0．98Mg0.02FeP04化合物，用X射线衍射(XRD)、透射电镜(TEM)和粒度分布仪研究了样品的物相结构、形貌和粒径分布。结果表明．采用该反应条件有利于控制产物的形貌和粒径以及易获得Fe^ 2稳定的磷酸铁锂化合物。分别用LiFePO4和Li0．98Mg0.02FeP04作正极材料进行了电池的充放电等电化学实验，其结果显示，材料中锂离子的充放电平台相对锂电极电位为3．5V左右，初始放电容量超过160mAh／g，50次充放电循环后容量仅衰减5．5％，表明用该方法制备的样品具有高的比能量和循环稳定性。

Fine-particle Lithium Iron(II) Phospho-olivine Prepared by A Novel Modified Solid-state Reaction

The fine-particle electroactive materials LiFePO_4 and Li_(0.98)Mg_(0.02)FePO_4 were synthesized by a novel modified solid-state reaction (MSR) method. The samples were characterized by X-ray diffraction, TEM and particle size analysis. The reaction conditions favor stabilization of the iron as Fe~(2+) as well as offering some control of the product morphology and particle size. The results of electrochemical evaluation of the products showed a lithium insertion plateau around 3.5 V vs. Li together with a specific capacity of over 160 mAh/g. Excellent electrochemical properties in terms of capacity, reversibility and cycling stability have been achieved. The MSR approach offers a scalable process as a convenient and energy-efficient method for preparation of great many electroactive phases.