通过新型喷雾干燥技术及热处理制备出具有球形二次形貌结构的纳米 LiFePO4/C 复合材料。首先合成了纳米FePO4颗粒(约20 nm),并与Li2 CO3和一定量的蔗糖均匀混合,对材料前驱体进行碳包覆,通过喷雾干燥获得了前驱体二次颗粒；经过热处理获得了由一次颗粒组成的二次颗粒。详细研究了碳含量对一次颗粒粒径及复合材料性能及形貌的影响,发现当LiFePO4/C 复合材料中碳含量为5.3%(质量分数),样品拥有良好的形貌结构和最佳的性能,0.1,1和5 C下的比容量分别为162,145和116 mAh/g。
A nano-sized LiFePO4/C composite with micro-spherical particles was synthesized by sintering the spherical precursor powders prepared using a new spray drying assisted method.In the first way,nano-sized FePO4 with size of 20 nm was prepared and well mixed with Li2 CO3 and certain mass of sucrose to obtain the precursor,after carbon coating and spray drying processes,a micro-spherical precursor powder was gained, which was followed by a certain thermal treatment,to achieve the preparation of the secondary particles of LiFePO4/C composite consisted of primary ones.The effects of carbon content on the performance and mor-phology of secondary particles were investigated.It was found that the optimal carbon content was 5.3wt%, and the sample delivered a good morphology structure and the highest specific capacity of 162,145 and 116 mAh/g at the rates of 0.1,1 and 5 C respectively.
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