以Fe_2O_3为铁源制备LiFePO_4/C及其电化学性能

Preparation and electrochemical performance of LiFePO_4/C using Fe_2O_3 as raw material

以Fe2O3和LiH2PO4为原料,聚丙烯为还原剂和碳源,采用一步固相法制备了LiFePO4/C复合正极材料,研究了不同温度对合成材料电化学性能的影响。利用X射线衍射(XRD)、扫描电子显微镜(SEM)等测试手段对合成材料进行了表征,通过恒电流充放电测试研究了材料的电化学性能。结果表明:于700℃下制备的LiFePO4/C复合材料在0.1、1、5C倍率下的首次放电比容量分别为160.4、143.0、108.3 mAh/g。在1 C和5 C经100次循环后,放电比容量分别为138.5 mAh/g和100.2 mAh/g,表现出良好的高倍率循环性能。

LiFePO4/C composites were synthesized by one-step solid-state reaction using Fe2O3and LiH2PO4 as raw materials, and polypropylene as reductive agent and carbon source. The effect of synthesis temperature on the electrochemical performance of the LiFePOJC composites was studied. The samples were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and so on. The electrochemical properties of the samples were investigated by galvanostatic tests. The results show that the sample synthesized at 700℃ exhibits a first discharge specific capacity of 160.4, 143.0, 1O8.3 mAh/g at 0.1, 1 Cand 5 C respectively. The sample also exhibits a good rate capability. After 100 cycles at 1 C and 5 C, the specific capacities of 138.5 and 100.2 mAh/g are still maintained.