Institute for Computational Physics, University of Stuttgart, Allmandring 3, D-70569 Stuttgart, Germany.
Max Planck Institute for Intelligent Systems, Heisenbergstrasse 3, D-70569 Stuttgart, Germany.
J Chem Phys. 2018 May 21;148(19):193824. doi: 10.1063/1.5016814.
We study generic properties of poly(ionic liquid)s (PILs) via coarse-grained molecular dynamics simulations in bulk solution and under confinement. The influence of different side chain lengths on the spatial properties of the PIL systems and on the ionic transport mechanism is investigated in detail. Our results reveal the formation of apolar and polar nanodomains with increasing side chain length in good agreement with previous results for molecular ionic liquids. The ion transport numbers are unaffected by the occurrence of these domains, and the corresponding values highlight the potential role of PILs as single-ion conductors in electrochemical devices. In contrast to bulk behavior, a pronounced formation of ion conductivity channels in confined systems is initiated in close vicinity to the boundaries. We observe higher ion conductivities in these channels for increasing PIL side chain lengths in comparison with bulk values and provide an explanation for this effect. The appearance of these domains points to an improved application of PILs in modern polymer electrolyte batteries.
我们通过在体相溶液和受限条件下的粗粒化分子动力学模拟来研究聚离子液体（PILs）的一般性质。详细研究了不同侧链长度对 PIL 体系的空间性质和离子输运机制的影响。我们的结果表明，随着侧链长度的增加，会形成非极性和极性纳米区，这与之前对分子离子液体的结果一致。离子迁移数不受这些区域的影响，相应的值突出了 PIL 作为电化学器件中单离子导体的潜在作用。与体相行为相比，在接近边界的地方，受限系统中会明显形成离子传导通道。与体相值相比，我们观察到随着 PIL 侧链长度的增加，这些通道中的离子电导率更高，并对此效应提供了一种解释。这些区域的出现表明，PIL 在现代聚合物电解质电池中的应用得到了改善。
