Mechanisms Underlying Ion Transport in Polymerized Ionic Liquids
Mechanisms Underlying Ion Transport in Polymerized Ionic Liquids
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DOI：
10.1021/jacs.7b05579
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发表时间：
2017-07-19
影响因子：
15
通讯作者：
Ganesan, Venkat
中科院分区：
文献类型：
--
作者：
Mogurampelly, Santosh;Keith, Jordan R.;Ganesan, Venkat
我们报告的原子分子动力学模拟的结果通知量子力学参数化的力场，它确定的机制，在聚（1-丁基-3-乙烯基咪唑-六氟磷酸盐）聚合的离子液体（聚IL）电解质的离子运动和扩散率。我们的研究结果表明，在聚离子液体中的阴离子传输发生通过一种机制，涉及内和分子间离子跳跃通过形成和打破涉及四个聚合的阳离子单体键合到两个不同的聚合物链的离子协会。所得到的离子迁移率与离子缔合的平均寿命直接相关。这种趋势被证明与纯离子液体中的行为相反，其中结构弛豫和相关的时间是主导机制。我们的研究结果建立了实验结果的基础上，报告离子在聚离子液体中的传输从聚合物链段弛豫解耦。
We report the results of atomistic molecular dynamics simulations informed by quantum-mechanically parametrized force fields, which identify the mechanisms underlying ion motion and diffusivities in poly(1-butyl-3-vinylimidazolium-hexafluorophosphate) polymerized ionic liquid (polyIL) electrolytes. Our results demonstrate that anion transport in polyILs occurs through a mechanism involving intra- and intermolecular ion hopping through formation and breaking of ion associations involving four polymerized cationic monomers bonded to two different polymer chains. The resulting ion mobilities are directly correlated to the average lifetimes of the ion-associations. Such a trend is demonstrated to contrast with the behavior in pure ILs, wherein structural relaxations and the associated times are dominant mechanism. Our results establish the basis for experimental findings that reported ion transport in polyILs to be decoupled from polymer segmental relaxations.