原料对固-液结合法合成LiMn_(0.5)Fe_(0.5)PO_4性能的影响

The effect of raw materials on the properties of LiMn_(0.5)Fe_(0.5)PO_4 by solid method

利用廉价原料以固-液结合法合成橄榄石结构的磷酸锰铁锂。用X射线衍射（XRD）、扫描电子显微镜（SEM）对不同原材料合成的目标产物微观结构及其形貌进行表征,通过恒流充放电测试其电化学性能。结果显示,由混合磷源及其廉价铁源、锰源合成的LiMn0.5Fe0.5PO4样品平均粒径在1~5μm之间,表面呈现出较规则的类球形。该样品在0.1C下恒流充放电初始放电容量达158.7 mAh/g,50周循环后为初始容量的94%,2C恒流充放电50周后容量为初始值的96%。研究表明以磷酸二氢铵与磷酸为混合磷源、工业级三氧化二铁及二氧化锰合成的LiMn0.5Fe0.5PO4材料具有较好的电化学性能。

The samples with olivine structure of lithium manganese iron phosphate （LiMn0.5Fe0.5PO4） were syn- thesized via solid-liquid method by cheap raw materials. Microstructure and morphology of the samples were re- spectively investigated by X-ray diffraction （XRD） and scanning electron microscopy （SEM）, Electrochemical properties were characterized via galvanostatic charge-discharge as well. The sample synthesized by the mixture of industrial grade Fe2O3 （95 0% ） and MnOz （85 % ） showed spherical shape with about 1 5 μm average particle si- zes. Galvan static charge-discharge test showed an initial discharge capacity of 158,7 mAh/g at 0.1 C. Capacity retention peHormanced 94% and 96% after 50 cycles during 0.1 and 2 C respectively. It suggests the synthesis of LiMn0.5Fe0.5PO4 via solid-liquid phosphorus with indurstrial grade materials （Fe2O3 and MnO2） is a promis- ing industrial method.