论文标题
离子电导率和掺杂盐聚合物的相关性：相互作用强度和浓度的影响
Ion Conductivity and Correlations in Model Salt-Doped Polymers: Effects of Interaction Strength and Concentration
论文作者
论文摘要
相关阴离子和阳离子运动可以显着降低电解质中的总离子电导率，而基于基于扩散常数计算的理想电导率。使用粗粒分子动力学模拟，我们计算了含盐均聚物中的电导率和无关的离子运动程度，并阻止共聚物的浓度和相互作用强度的函数。在应用电场下，从离子迁移率的电导率计算可提高精度，而在平衡模拟中使用波动耗散关系的典型使用。在典型的电解质中，阳离子 - 大动脉运动的相关性通常预计在低离子浓度下会降低。但是，对于具有强离子聚合物和离子离子相互作用的这些聚合物电解质，我们发现当其他变量保持恒定时，相关性在较低的浓度下增加。我们显示，这种现象与低浓度的离子簇松弛率较慢，而不是离子聚集的静态空间状态或自由离子的分数。
Correlated anion and cation motion can significantly reduce the overall ion conductivity in electrolytes versus the ideal conductivity calculated based on the diffusion constants alone. Using coarse-grained molecular dynamics simulations, we calculate conductivity and the degree of uncorrelated ion motion in salt-doped homopolymers and block copolymers as a function of concentration and interaction strengths. Calculating conductivity from ion mobility under an applied electric field increases accuracy versus the typical use of fluctuation dissipation relationships in equilibrium simulations. In typical electrolytes, correlation in cation-anion motion is often expected to be reduced at low ion concentrations. However, for these polymer electrolytes with strong ion-polymer and ion-ion interactions, we find correlations are increased at lower concentrations when other variables are held constant. We show this phenomenon is related to the slower ion cluster relaxation rate at low concentrations rather than the static spatial state of ion aggregation or the fraction of free ions.
