Zn^(2+)、Ge^(4+)的取代对Li_5AlSi_2O_8的影响

The effect of Zn^(2+), Ge^(4+) on modified Li_5AlSi_2O_8

尝试以叶腊石为基体 ,通过高温固相反应 ,合成通式为Li5+xAl1-xZnxSi2 -2xGe2xO8(x =0 .0～ 1.0 )系统锂快离子导体。X射线粉末衍射表明当x≤ 0 .3时体系仍维持原有的Li5AlSi2 O8结构 (正交晶系 ) ;x >0 .5时结构发生明显变化 ,体系转变成Li6ZnGe2 O8。红外检测显示当x≥ 0 .1红外谱图中出现Li2 CO3 吸收峰 ,表明在室温下体系中的Ge4+ 吸收空气中的CO2而发生分解反应。交流阻抗技术测试交流阻抗表明当温度大于2 0 0℃时体系有较高的电导率 ,最高时为 1.11× 10 -2 S/cm(4 0 0℃ ,x =1.0 ) ,x≤ 0 .5时离子电导率很低 。

Based on pyrophyllite, there was preparation of Li 5+ x Al 1- x Zn x Si 2-2 x Ge 2 x O 8 ( x =0.0～1.0) lithium fase ionic conductor through high temperatreu reaction. X ray powder diffraction indicate that the system maintain the structure of Li 5AlSi 2O 8 while x ≤0.3, and the structure change evidently to that of Li 6ZnGe 2O 8. IR show that there was absorption of Li 2CO 3 when x ≥0.1, this indicate that the Ge 4+ absorb the CO 2 from the air and the composition decomposed. AC impedance showed when the temperature was above 200℃, there was a good conductivity as high as to 1.11×10 -2 S/cm (400℃, x =1.0), but the conductivity was lower and not depend on temperature while x ≤0.5.