Fundamental Limitations of Ionic Conductivity in Polymerized Ionic Liquids
Fundamental Limitations of Ionic Conductivity in Polymerized Ionic Liquids
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DOI：
10.1021/acs.macromol.8b01221
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发表时间：
2018-11-13
期刊：
影响因子：
5.5
通讯作者：
Sokolov, Alexei P.
中科院分区：
文献类型：
--
作者：
Stacy, Eric W.;Gainaru, Catalin P.;Sokolov, Alexei P.
本文详细研究了几种不同移动的离子尺寸的聚合离子液体的离子电导率。提出的分析表明，在聚离子液体中的电荷扩散比离子扩散慢约10倍，这表明强的离子-离子相关性降低了离子电导率。的离子扩散的活化能显示出非单调的依赖于移动的离子的大小，表明库仑力和弹性力之间的竞争控制离子在聚离子液体的传输。前者支配小离子的迁移率（例如，Li），而后者控制大离子的迁移率（例如，测试）。我们提出了一个简单的定性模型描述的激活能的离子扩散。这表明，聚离子液体的介电常数的增加应该导致小离子（例如，Li和Na）。
We present detailed studies of ionic conductivity in several polymerized ionic liquids (PolyILs) with different size of mobile ions. Presented analysis revealed that charge diffusion in PolyILs is about 10 times slower than ion diffusion, suggesting strong ion-ion correlations that reduce ionic conductivity. The activation energy for the ion diffusion shows a nonmonotonous dependence on the mobile ion size, indicating a competition between Coulombic and elastic forces controlling ion transport in PolyILs. The former dominates mobility of small ions (e.g., Li), while the latter controls mobility of large ions (e.g., TEST). We propose a simple qualitative model describing the activation energy for the ion diffusion. It suggests that an increase in dielectric constant of PolyILs should lead to a significant enhancement of conductivity of small ions (e.g., Li and Na).