LiFePO_4/C的制备及其电化学性能研究  

Synthesis and Electrochemical Performance of LiFePO_4/C Samples

作　　者：卢阳[1] 童庆松[1] 翁秀燕[1] 李变云[1] 黄维静[1] 

机构地区：[1]福建师范大学化学与材料学院,福建福州350108

出　　处：《福建师范大学学报（自然科学版）》2009年第4期67-71,共5页Journal of Fujian Normal University：Natural Science Edition

基　　金：教育部重点项目(03065);福建省教育厅基金资助项目(JA07033);福建省自然科学基金资助项目(2008J0144)

摘　　要：采用固相烧结法,在惰性气氛下制备了橄榄石型LiFePO4/C正极材料.通过充放电循环实验、循环伏安实验、交流阻抗、拉曼光谱等测试方法,研究了样品的优化制备条件与电化学性能的关系.研究表明,当以草酸亚铁为铁源时,720℃烧结的样品以1C倍率电流充放电时,首次放电容量为113mAh/g,50循环的放电容量为116mAh/g,表现出优秀的循环稳定性.在30循环内,样品的电荷传递阻抗随着充放电循环的进行而减小.锂离子扩散系数为1.56×10-8cm2/s.A series of LiFePOJC samples were prepared by using a solid-state sintering method in a inertia atmosphere. Charge-discharge cycle, cyclic voltammogram, electrochemical impedance and Raman spectra were employed to study the relationship between optimization synthesis condition and electrochemical performance. Experimental result that the asprepared sample exhibits the best electrochemical performance in all samples while FeC2O4 was selected as an iron source at 720 ℃, which exhibits a capacity of 113 mAh/g in the 1st cycle and 116 mAh/g in the 50th cycle at a current of 1 C. The charge transfer impedance for the as-prepared decreased with cycling in 30 cycles. The diffusion coefficient of lithium ions is 1.56 ×10^-8cm^2/s.

关 键 词：锂离子电池 固相烧结 正极材料 磷酸亚铁锂 

分 类 号：TM912[电气工程—电力电子与电力传动] TG139.7[一般工业技术—材料科学与工程]