基于微米氧化铁的LiFePO_4/C正极材料制备及性能研究

Preparation of LiFePO_4/C cathode material with micron-Fe_2O_3 and performance analysis

文章以微米级氧化铁为原料,通过前驱体预处理合成LiFePO4/C正极材料,采用X射线衍射(XRD)、扫描电子显微镜(SEM)及透射电子显微镜(TEM)等手段对合成的磷酸铁锂材料结构和微观形貌进行表征,考察了不同球磨时间对浆料粒径的影响,分析了前驱体预处理对合成产物性能提升的原因。结果表明,以微米氧化铁为原料,经过预处理后制备得到的LiFePO4/C正极材料的电化学性能具有明显改善,0.2C和1C条件下,放电容量较之前驱体未处理样品分别提高了22.5%和27.3%,合成样品性能改善的主要原因在于前驱体预处理降低了二次团聚体粒径。

LiFePO4/C cathode material was prepared by precursor pretreatment method with micron‐Fe2 O3 as raw material .The structural and morphological characteristics of the prepared LiFePO 4/C were characterized by X‐ray diffraction（XRD） ,scanning electron microscope（SEM） and transmission electron microscope（TEM） .The effect of different milling time on the size of mixture was investiga‐ted ,and the reasons for precursor pretreatment in improving the performance of material were ana‐lyzed .The experimental results show that the prepared sample with pretreatment exhibits the good electrochemical performance and the discharge capacity at 0.2C increases 22.5% and at 1C increases 27.3% ,which is higher than that of LiFePO4/C without pretreatment ,respectively .The precursor pretreatment is helpful in improving the electrochemical performance ,because the method can reduce the size of secondary aggregate .