Ion Conductivity and Correlations in Model Salt-Doped Polymers: Effects of Interaction Strength and Concentration
Ion Conductivity and Correlations in Model Salt-Doped Polymers: Effects of Interaction Strength and Concentration
复制标题
模型盐掺杂聚合物中的离子电导率和相关性：相互作用强度和浓度的影响
DOI：
10.1021/acs.macromol.0c00216
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
L. Hall
中科院分区：
文献类型：
--
作者：
Kuan;L. Hall
与仅基于扩散常数计算的理想电导率相比，相关的阴离子和阳离子运动可以显著降低电解质中的总离子电导率。使用粗粒度的分子动力学模拟，我们计算电导率和不相关的离子运动的程度在盐掺杂的均聚物和嵌段共聚物作为浓度和相互作用强度的函数。与平衡模拟中波动耗散关系的典型使用相比，在施加的电场下从离子迁移率计算电导率增加了准确性。在典型的电解质中，通常预期阳离子-阴离子运动的相关性在低离子浓度下降低。然而，对于这些具有强离子-聚合物和离子-离子相互作用的聚合物电解质，我们发现当其他变量保持恒定时，相关性在较低浓度下增加。我们发现，这种现象是有关在低浓度下，而不是静态的空间状态的离子聚集或自由离子的分数较慢的离子簇弛豫速率。
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.
DOI：
10.1063/1.5016814
发表时间：
2018-02
期刊：
The Journal of chemical physics
影响因子：
--
作者：
Alexander Weyman;M. Bier;Christian Holm-;Jens Smiatek
通讯作者：
Alexander Weyman;M. Bier;Christian Holm-;Jens Smiatek
影响因子：
5.5
作者：
Bill K. Wheatle;Nathaniel A. Lynd;V. Ganesan
通讯作者：
Bill K. Wheatle;Nathaniel A. Lynd;V. Ganesan
影响因子：
5.5
作者：
Stacy, Eric W.;Gainaru, Catalin P.;Sokolov, Alexei P.
通讯作者：
Sokolov, Alexei P.