共沉淀法制备锂离子电池正极材料LiFePO4及其性能研究

用共沉淀的方法制备了改性的锂离子电池正极材料LiFePO4,利用X射线衍射(XRD)、扫描电镜(SEM)、傅立叶红外光谱(FTIR)等方法对样品的晶体结构、表观形貌、谱学性质等进行了分析研究,并在表观形貌和电性能上与固相法制备的样品进行比较.结果表明,此种方法制备的LiFePO4为单一的橄榄石型晶体结构,具有3.4V左右的放电电压平台,该材料具有良好的电性能,分别以0.2,0.4mA/cm2的电流密度充放电,首次放电比容量达到142.3,127mAh/g,充放电循环20次后放电比容量仍保持在129.7,105.5mAh/g.

Synthesis of LiFePO4 by Liquid-state Co-precipitation Method and Its Performance

The cathode materials of LiFePO_4 were synthesized under liquid-state co-precipitation method. The crystalline structures,morphology of particles,spectroscopic character were investigated by X-ray diffraction, scanning electron microscopy and FTIR. Morphology of particles and electrochemical performance were also compared with that synthesized by solid-state reaction. The results showed that LiFePO_4 were simple pure olive-type phase, and exhibit a 3.4V discharge voltage plateau.LiFePO_4 as prepared possessed excellent electrochemical performance, whose first specific capacities were 142.3mAh/g at 0.2mA/cm 2,127 mAh/g at 0.4 mA/cm 2, after 20 times cycling, the specific capacities were 129.7mAh/g,105.5mAh/g respectively.