LiFe_1-xMg_xPO₄/C的制备和性能研究(英文)  

Synthesis and Characterization of LiFe_(1-x)Mg_xPO_4/C Composite Cathode Materials

作　　者：胡成林[1] 戴永年[1] 于逢婕[1] 易惠华[1] 姚耀春[1] 

机构地区：[1]昆明理工大学材料与冶金工程学院∥真空冶金国家工程实验室

出　　处：《中山大学学报（自然科学版）》2009年第S2期28-30,共3页Acta Scientiarum Naturalium Universitatis Sunyatseni

基　　金：云南省自然科学基金资助项目(2004E009Q)

摘　　要：以乙酸镁为掺杂元素、蔗糖为碳源,采用固相反应法制备镁掺杂磷酸铁锂包覆碳复合材料LiFe_1-xMg_xPO₄/C（x=0.01,0.02,0.03,0.04）。利用X射线衍射（XRD）分析其结构,扫描电镜（SEM）观察其形貌,恒电流法测定其电化学性能。研究结果表明镁离子掺杂没有影响材料的结构,而是提高了其放电容量和循环性能。在这些样品中,LiFe_0.98Mg_0.02PO₄/C的容量最高,首次放电达到140.0mAh/g;并且在80次循环后容量没有衰减反而增加到148.6mAh/g左右。LiFe_(1-x)Mg_xPO_4/C(x =0.01,0.02,0.03,0.04) composites were prepared by solid state reaction method using magnesium acetate as dopant and sucrose as carbon source.The structural,morphological and electrochemical properties were investigated by means of X-ray powder diffraction(XRD),scanning electron microscopy(SEM) and constant current charge-discharge cycling.The results indicate that magnesium ion dopant does not affect the structure of the material but considerably improves its capacity and cycle performance.Among the samples,LiFe_(0.98)Mg_(0.02)PO_4/C shows the best capacity of 140.0 mAh/g in the first discharge and its capacity increases to 148.6 mAh/g without capacity fading after 80 cycles.

关 键 词：锂离子电池 正极材料 磷酸铁锂 掺杂 

分 类 号：TM912.9[电气工程—电力电子与电力传动]