采用高温固相法合成锂离子电池正极材料LiFe0.9Ni0.1PO4研究了反应条件对合成产物的影响。利用X射线衍射(XRD)和扫描电镜(SEM)对所得样品的晶体结构、表面形貌等进行了表征。结果表明:反应温度和时间对LiFe0.9Ni0.1PO4晶体结构及材料性能均有较大影响,其中650℃下焙烧20h合成出的样品电化学性能最佳;在20mA/g的电流密度下进行恒流充放电时,首次放电比容量可达145mA·h/g,循环30次后比容量仍为135mA·h/g,容量衰减仅为6.9%。
LiFe0.9Ni0.1PO4 for cathode materials of lithium-ion battery was synthesized by solid-state reaction. The effects of synthesis temperature and reaction time on the electrochemical performance were studied systematically. The crystalline structure and microstructures of resulting specimens were characterized by X-ray diffractometry (XRD) and scanning electromicroscopy (SEM). The results show that the reaction temperature and time have great effect on the structures and electrochemical performance of the obtained samples. Further electrochemical tests indi- cate that the material synthesized optimally at 650℃ for 20 h possesses excellent electrochemical performance. The first discharge capacity of LiFe0.9 Ni0.1 PO4 on 20 mA/g current density arrives at 145 mA · h/g and after 30 times cycling the discharge capacity is still up to 135 mA· h/g, only with about 6.9% capacity fade.