LiFePO_4/C的电化学性能  

Electrochemical performance of LiFePO_4/C samples

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

机构地区：[1]福建师范大学化学与材料学院,福建福州350007

出　　处：《吉林化工学院学报》2009年第3期5-8,共4页Journal of Jilin Institute of Chemical Technology

基　　金：教育部重点资助项目(03065;JA07033);福建省发改委资助项目(闽发改高技2008(794));福建省自然科学基金(2008J0144)资助项目

摘　　要：采用固相烧结法,在惰性气氛下制备了橄榄石型L iFePO4/C正极材料.通过充放电循环实验、循环伏安实验、交流阻抗、拉曼光谱等现代手段,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,在720℃烧结的样品以1C倍率电流充放电时,首次放电容量为113 mAh/g,50循环的放电容量为116 mAh/g,表现出优秀的循环稳定性.锂离子扩散系数为1.56×10-8cm2/s.在30循环内,样品的电荷传递阻抗随着充放电循环的进行逐渐减小.Several LiFePO4/C samples were prepared by using a solid-state sintering method in an inertia atmosphere at different temperature. Charge-discharge cycle, cyclic vohammogram, electrochemical impedance and Raman spectra were employed to study the relationship between optimization synthesis condition and elec-trochemical performance. Experimental results show that the as-prepared sample exhibits the best electrochemical performance in all samples while FeC2O4 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 1C. The diffusion coefficient of lithium ions is 1. 56×10^-8 cm^2/s. The charge transfer impedance for the as-prepared decreased with cycling in 30 cycles.

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]