锂离子电池正极材料LiFePO_4C的制备与表征

Preparation and Characterization of LiFePO_4/C as Cathode Material for Lithium Ion Batteries

采用溶胶-凝胶法合成了LiFePO4 C复合材料,利用元素分析、X射线衍射(XRD)、扫描电镜(SEM)等方法对其进行了表征,将其组装成模拟电池测试了其电化学性能.结果表明:LiFePO4 C具有单一的橄榄石型晶体结构,碳粒子平均颗粒大小在1μm左右.LiFePO4 C复合材料在3.4V处具有很好的充放电电压平台,与LiFePO4相比,具有更高的放电比容量和更好的循环性能,在60℃时的首次放电容量达到133mAh g,经20次循环后的容量保持率为93.8%.

LiFePO_4/C composite cathode materials for lithium-ion battery were synthesized by sol-gel method, and characterized by element analysis,X-ray diffraction (XRD), scanning electron microscopy (SEM). The electrochemical properties were tested using analogous cells. Results showed that LiFePO_4/C were simple pure olive-type phase with uniform particle size of 1μm. LiFePO_4/C showed a good charge-discharge voltage plateau at 3.4 V and higher capacity and better cyclability compared with LiFePO_4.The first specific discharge capacities were 133 mAh/g, and 93.8% of which retained after 20 times cycling at 60 ℃.