摘要
采用机械液相活化法合成了具有尖晶石结构的可用作锂离子蓄电池正极材料的LiMn2O4化合物,并对其进行了掺杂稀土铕(Eu)元素的修饰。对材料进行了X射线衍射、循环伏安、充放电等测试。实验结果表明,掺入铕元素所合成的材料具有标准尖晶石结构,较好的电化学可逆性能,较优良的高温性能。该材料在EC+DMC(1:1)+1mol/L LiPF6电解液中表现出了较优良的充放电性能,其首次放电比容量达130 mAh/g。以中间相碳微球做负极时,在室温下经300次循环后,容量持有率大于85%,在55℃下,经200次循环后容量持有率大于80%。同时运用用晶体场理论简要分析了稀土Eu在尖石结构中的作用机理。
The spinel LiMn2O4 used as cathode materials for lithium-ion batteries was synthesized by mechanical fluid activation process, and modified by doping rare-earth Eu. Testing of X-ray diffraction , cyclic voltammograms , charge-discharge and SEM was carried out for LiMn2O4 cathode materials and the modified materials. Results show that the synthesized materials doping by Eu exhibite standard spinel structure, high reversibility of electrochemistry and excellent properties of charge-discharge. In EC+DMC(1∶1)+1 mol/L LiPF6 electrolyte with discharge specific capacity more than 130 mAh/g., its capacity was deteriorated less than 15% after 300 cycles at RT and less than 20% after 200 cycles at 55 ℃. At the same time, Crystal Field Theory was applied to explain the function and mechanism of doped rare earth element.
出处
《电源技术》
CAS
CSCD
北大核心
2004年第5期264-267,共4页
Chinese Journal of Power Sources
基金
湖南省自然科学基金资助项目(02 JJY 2081)
