期刊
ACS MACRO LETTERS
卷 2, 期 4, 页码 322-326出版社
AMER CHEMICAL SOC
DOI: 10.1021/mz3006457
关键词
-
资金
- NRW Graduate School of Chemistry
The lithium transport mechanism in ternary polymer electrolytes, consisting of PEO20LiTFSI and various fractions of the ionic liquid PYR13TFSI, is investigated by means of MD simulations. This is motivated by recent experimental findings (Passerini et al. Electrochim. Acta 2012, 86, 330), which demonstrated that these materials display an enhanced lithium mobility relative to their binary counterpart PEO20LiTFSI. In order to grasp the underlying microscopic scenario giving rise to these observations, we employ an analytical, Rouse-based cation transport model (Maitra et al. Phys. Rev. Lett. 2007, 98, 227802), which has originally been devised for conventional polymer electrolytes. This model describes the cation transport via three different mechanisms, each characterized by an individual time scale. It turns out that also in the ternary electrolytes essentially all lithium ions are coordinated by PEO chains, thus, ruling out a transport mechanism enhanced by the presence of ionic-liquid molecules. Rather, the plasticizing effect of the ionic liquid contributes to the increased lithium mobility by enhancing the dynamics of the PEO chains and consequently also the motion of the attached ions. Additional focus is laid on the prediction of lithium diffusion coefficients from the simulation data for various chain lengths and the comparison with experimental data, thus demonstrating the broad applicability of our approach.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据