摘要
以Li2CO3和TiO2为原料,固相法合成了不同Li2CO3过量的Li4Ti5O12(简称LTO),通过X射线衍射法(XRD)对LTO相和残余TiO2相的定量分析计算了合成纯的LTO所需Li2CO3原料过量程度。Li2CO3过量起到两方面的作用:(1)补充高温合成LTO过程中所挥发的锂,从而减少TiO2含量;(2)造成一些Li+进入LTO晶格取代部分Ti4+,使得LTO的电导率增加,过多的取代量会降低LTO的比容量。这两种作用决定了Li2CO3过量对LTO的充放电性能具有显著影响,综合结果表明,Li2CO3过量5%所制备LTO具有最佳电化学储锂性能。
Li4Ti5O12 （LTO） was synthesized by solid state reaction using Li2CO3 and TiO2. The required degree of Li2CO3 for synthesizing pure LTO was calculated by XRD quantitative analysis. With the increase of excessive amount of Li2CO3, there were two factors influencing the properties of LTO： on the one hand, it compensated for the loss of Li^＋ when synthesized at high temperature and then decreased the amount of TiO2 existing in the LTO; on the other hand, Li^＋ substituted for part of Ti^＋4＋ in LTO, this increased the conductivity of LTO and it would decrease the specific capacity when too much Ti^4＋ was substituted. The charge-discharge capacity was affected significantly by these two factors. The experiment results show that the most appropriate excessive amount of Li2CO3 is 5%.
出处
《电源技术》
CAS
CSCD
北大核心
2009年第11期974-976,共3页
Chinese Journal of Power Sources
