Effect of Polymer Polarity on Ion Transport: A Competition between Ion Aggregation and Polymer Segmental Dynamics
Effect of Polymer Polarity on Ion Transport: A Competition between Ion Aggregation and Polymer Segmental Dynamics
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DOI：
10.1021/acsmacrolett.8b00594
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发表时间：
2018-10-01
影响因子：
7.015
通讯作者：
Ganesan, Venkat
中科院分区：
文献类型：
--
作者：
Wheatle, Bill K.;Lynd, Nathaniel A.;Ganesan, Venkat
在这项工作中，我们使用计算机模拟来证明，单独使用聚合物极性来影响盐掺杂聚合物电解质的离子电导率可能是有限的。具体来说，我们使用粗粒度的分子动力学模拟来探测聚合物电解质的极性对离子迁移率和溶解盐电导率的影响。在聚合物极性较低时，增加聚合物介电常数可减少离子聚集和由此产生的相关离子运动，并提高离子电导率。在较高的聚合物极性下，聚合物-聚合物和聚合物离子的相互作用减慢了聚合物的段动力学，导致电解质的导电性降低。因此，离子电导率在中间聚合物极性处达到最佳。
In this work, we use computer simulations to demonstrate that there may be limits to which polymer polarity alone can be used to influence the ionic conductivity of salt-doped polymer electrolytes. Specifically, we use coarse-grained molecular dynamics simulations to probe the effect of the polarity of the polymer electrolyte upon ion mobilities and conductivities of dissolved salts. At low polymer polarities, increasing the polymer dielectric constant reduces ionic aggregation and the resultant correlated ionic motion, and increases the ionic conductivity. At higher polymer polarities, polymer-polymer and polymer ion interactions slows polymer segmental dynamics, leading to a reduction in the conductivity of the electrolyte. As a consequence, ionic conductivity achieves an optimum at an intermediate polymer polarity.