锂电池正极材料磷酸铁锂的前驱体磷酸铁的制备

Preparation of LiFePO_4 precursor FePO_4 for lithium cathode material

以九水硝酸铁和磷酸二氢铵为原材料,采用共沉淀法来制备锂电池正极材料磷酸铁锂的前驱体磷酸铁,用氨水调节p H,通过改变反应温度、分散剂的种类、加料时长、煅烧温度等进行实验,用XRD、SEM等对样品进行表征。研究发现温度为90℃,加料时长为1min,以聚乙烯吡咯烷酮作为分散剂的条件下,能制备出纳米级、大小比较均匀、表面比较光滑的无定性体前驱体材料。对这种无定性体的煅烧实验表明,煅烧温度越高结晶度越好,温度达650℃时可以得到结晶度良好的前驱体颗粒。

The LiFePO4 precursor FePO4for lithium cathode material was prepared by the method of coprecipitation with Fe（ NO3 ） 3·9H2O and NH4H2PO4 as raw materials, pH was adjusted by NH3·H2O. The experiments were done by changing reaction temperature, the kinds of dispersant, the loading time and calcination temperature. The samples were characterized by SEM and XRD. Results showed that when temperature was 90℃, the loading time was 1 minute, and PVP was used as dispersant, the amorphous precursor materials of nano - level, uniformed size and smooth surface were prepared. The calcining experiment of amorphous form showed the higher calcination temperature was, the better crystalline, and the crystallinity of the precursor granules could be obtained at 650℃.