原位复合制备Li_4Ti_5O_(12)包覆石墨及电性能研究  

Preparation and performance of graphite coated with Li_4Ti_5O_(12) anode material by in-situ composite

作　　者：向宇[1] 洪晓斌[1] 李德湛[1] 胡芸[1] 

机构地区：[1]国防科学技术大学航天与材料工程学院,湖南长沙410073

出　　处：《电源技术》2011年第9期1065-1068,共4页Chinese Journal of Power Sources

摘　　要：以醋酸锂、钛酸丁酯为原料,乙醇为溶剂,采用原位复合法制备Li4Ti5O12包覆石墨新型负极材料,记为LTO-G。采用扫描电镜(SEM)、能谱分析(EDS)、电化学和交流阻抗测试对LTO-G进行表征。结果表明石墨表面包覆了一层Li4Ti5O12,使得首次的可逆容量和库仑效率达到346.2 mAh/g和94%,分别比原始石墨高出了20 mAh/g和6%。0、-10℃的恒流充放电测试发现,LTO-G的嵌锂比容量相对于原始石墨有了很大提高,而且通过交流阻抗测试发现低温时LTO-G的SEI膜离子迁移电阻RSEI和界面电荷转移电阻Rct相对于原始石墨降低很多。A new anode material named LTO-G was synthesized by in-situ composite technique using graphite, lithium acetate, tetrabutyl titanate as starting material and was characterized by various electrochemical methods in combination with scanning electron microscopy（SEM）, energy spectrum, electrochemical impedance spectroscopy. The results show that Li4Ti5O12 is coated on the surface of graphite, and the reversible capacity and coulomb efficiency of LTO-G at the first cycle are 346.2 mAh/g and 94%, which is 20 mAh/g and 6% higher than the original graphite separately. At 0 and-10 ℃, LTO-G has a much better behavior than original graphite. Under low temperature, the resistance across the SEI （RsB） and the charge-transfer resistance at the electrode （RCI） are greatly decreased.

关 键 词：原位复合法 石墨负极 低温性能 LI4TI5O12 

分 类 号：TM912.9[电气工程—电力电子与电力传动]