Microphase separation and the formation of ion conductivity channels in poly(ionic liquid)s: A coarse-grained molecular dynamics study.
Microphase separation and the formation of ion conductivity channels in poly(ionic liquid)s: A coarse-grained molecular dynamics study.
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DOI：
10.1063/1.5016814
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发表时间：
2018-02
期刊：
影响因子：
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通讯作者：
Alexander Weyman;M. Bier;Christian Holm-;Jens Smiatek
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文献类型：
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作者：
Alexander Weyman;M. Bier;Christian Holm-;Jens Smiatek
我们通过本体溶液和约束条件下的粗粒度分子动力学模拟研究聚（离子液体）（PIL）的一般性质。详细研究了不同侧链长度对 PIL 系统空间特性和离子传输机制的影响。我们的结果揭示了侧链长度增加的非极性和极性纳米域的形成，与分子离子液体的先前结果非常一致。离子传输数不受这些域的影响，相应的值突出了 PIL 作为电化学装置中单离子导体的潜在作用。与本体行为相反，受限系统中离子传导通道的明显形成是在边界附近开始的。与体积值相比，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，并对此效应提供了解释。这些域的出现表明 PIL 在现代聚合物电解质电池中的应用得到了改进。
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.