磷酸铁锂正极材料中锂离子扩散系数的测定  

Determination of Li^+ Diffusion Coefficient of LiFePO_4 Cathode Materials

作　　者：任冬燕[1,2] 任东兴[2] 李晶[3] 宋月丽[3] 

机构地区：[1]绵阳职业技术学院材料工程系,四川绵阳621000 [2]金川集团股份有限公司,甘肃金昌737100 [3]西南科技大学材料科学与工程学院,四川绵阳621000

出　　处：《广州化工》2012年第15期108-109,112,共3页GuangZhou Chemical Industry

摘　　要：通过碳热还原法制备了磷酸铁锂正极材料,并采用恒电位阶跃法测定了磷酸铁锂正极材料在不同电位和循环次数下的锂离子扩散系数,通过XRD对循环前后磷酸铁锂材料的晶体结构进行了表征,并对磷酸铁锂材料的失效模式进行了简单的分析。结果表明:LiFePO4在充放电过程中锂离子扩散系数随Li含量的增大,呈现先增大后略微降低的规律。随着充放电循环次数的增多,LiFePO4中Li+的固相扩散系数值明显下降。LiFePO4 cathode materials was prepared by carbothermal reduction reaction.The potentiostatic intermittent titration technique（PSAC） was used to examinate the Li＋ion diffusion coefficient of LiFePO4 cathode materials at different voltage and at different charge/discharge cycles.The structure of LiFePO4 was studied before and after charge-discharge cycles by XRD technique.And preliminary failue anlysis of LiFePO4 was also conducted.The results indicated that the Li＋ diffusion coefficient may increse at first then reduced with the increase of Li＋ contents.The Li＋ diffusion coefficient reduced tendency with the increase of cycle number.

关 键 词：磷酸铁锂 锂离子扩散系数 恒电位阶跃 循环性能 

分 类 号：TB34[一般工业技术—材料科学与工程]