Ionic Diffusion Mechanism of Glucitol-Containing Lithium Polymer Electrolytes
Ionic Diffusion Mechanism of Glucitol-Containing Lithium Polymer Electrolytes
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DOI：
10.1021/ma050503v
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发表时间：
2005-06
期刊：
影响因子：
5.5
通讯作者：
Yuria Saito;K. Hirai;H. Katayama;Toshihiro Abe;M. Yokoe;K. Aoi;M. Okada
中科院分区：
文献类型：
--
作者：
Yuria Saito;K. Hirai;H. Katayama;Toshihiro Abe;M. Yokoe;K. Aoi;M. Okada
通过观察反映载流子扩散行为的脉冲梯度自旋回波核磁共振的回声强度变化，研究了离子物种在葡糖醇型锂聚合物电解质中的限制扩散。回声衰减表现出异常特征，可归因于由于扩散受限而偏离随机漫步迁移。衰减行为取决于用于测量的扩散时间Δ，范围为40ms；Δ<；160ms。这表明，导致扩散限制的边界结构尺寸为微米量级。我们推测，一种微米尺寸的结构域，即缠绕在一起的高分子链的聚集单元，是造成扩散限制的原因。基于矩形模型的模拟显示了两个主要因素的回声变化行为的特征：固有扩散系数D和微区尺寸a，这取决于聚合物电解质的观测温度T和盐浓度C的可变参数。E..。
We investigated restricted diffusion of ionic species in glucitol-type lithium polymer electrolytes by observing echo-intensity changes of pulsed gradient spin echo NMR which reflect carrier diffusion behavior. Echo attenuation showed an anomalous feature attributable to deviation from random walk migration due to the restricted diffusion. The attenuation behavior depended on the diffusion time for measurement, Δ, in the range of 40 ms < Δ < 160 ms. This revealed that the size of the boundary structure which causes diffusion restriction was micrometer order. We speculated that a kind of micron size domain, which is an aggregation unit of entangled polymer chains, is responsible for the diffusion restriction. Simulations based on a rectangular model showed characteristic features of echo-changing behavior against two dominant factors: inherent diffusion coefficient, D, and domain size, a, which depend on variable parameters, observed temperature, T, and salt concentration, C, of the polymer electrolyte. E...