前驱体酸碱添加剂对溶胶凝胶法制备LiFePO_4的影响

Influences of Precursor pH Value on the Sol-Gel Prepared LiFePO_4

溶胶凝胶法作为一种常见的软化学方法用于LiFePO4锂离子正极材料的制备。通过在前驱体中添加盐酸或者氨水,考察不同酸碱添加剂对LiFePO4性能的影响。X射线衍射分析(XRD)和扫描电子显微镜(SEM)用于材料物相及形貌的分析和表征,通过正极材料在空气中加热前后质量差计算得到正极材料中的碳含量。加入盐酸的样品的颗粒尺寸、碳含量及可逆容量得到较为明显的改善,在低充放速率下达到140mAh/g的容量。

The frequently used soft chemistry sol-gel method is employed to prepare the LiFePO4 lithium-ion cathode material. HCl or ammonia solution is added into the precursor to investigate their influences. X-ray diffraction （XRD） and scanning electron microscope （SEM） are utilized to characterize the properties of the cathode materials. Carbon content is calculated according to the weight difference of the LiFePO4 cathode material before and after heating. Samples added HCl show obvious improvement in particle size and carbon content control, and reach to an inverse capacity of 140 mAh/g under lower charge/discharge rate.