氟代硼酸锂玻璃的分子动力学模拟

Molecular Dynamics Simulation of Fast Li^+ Conduction in Fluoroborate Glasses

用分子动力学模拟方法,计算了氟代硼酸锂玻璃的电导率.研究的温度范围高于和近于玻璃转变温度,共模拟了七个体系,研究的成分大致覆盖了能形成玻璃的区域.所得极限电导率、活化能以及电导率随温度的变化与实验数据符合得相当好.以往的研究认为快离子传导的典型特征是仅有一种离子发生迁移,我们的模拟表明氟离子对电导也有较大贡献.用活化能数据可顺利解释这个三元系各体系的电导率相对高低问题.

The conductivities in Fluoroborate glasses were calculated by molecular dynamics simulation method at near and higher than glass transition temperatures.There are seven simulated systems which coverd almost all glass formation area in Li2O LiF B2O3 system.The limited conductivities and their change with temperature,activition energy of MD simulation are well in agreement with experimental data. Some early researches showed that in fast conducting solid electrolytes one of their typical characteristics is that only one kind of carrier ion migrates.It was shown that in our simulation the contribution to electrical conductivity from F ion must be taken into account.Using activation energy data,the relative conductivites among those simulated systems and experimental systems can be explained perfectly.