Double Layer in Ionic Liquids: Overscreening versus Crowding
Double Layer in Ionic Liquids: Overscreening versus Crowding
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DOI：
10.1103/physrevlett.106.046102
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发表时间：
2011-01-24
影响因子：
8.6
通讯作者：
Kornyshev, Alexei A.
中科院分区：
文献类型：
--
作者：
Bazant, Martin Z.;Storey, Brian D.;Kornyshev, Alexei A.
我们开发了一种简单的无溶剂离子液体的朗道-金兹堡型连续介质理论，并用它来预测双电层的结构。该模型捕获了短程相关性的过度筛选（在小电压下占主导地位）以及有限离子尺寸的空间约束（在大电压下占主导地位）。增加电压逐渐抑制过度筛选，有利于电极附近凝聚内层中反离子的拥挤。该预测、离子分布和电容电压依赖性与最近对室温离子液体的计算机模拟和实验一致，使用离子尺寸量级的相关长度。
We develop a simple Landau-Ginzburg-type continuum theory of solvent-free ionic liquids and use it to predict the structure of the electrical double layer. The model captures overscreening from short-range correlations, dominant at small voltages, and steric constraints of finite ion sizes, which prevail at large voltages. Increasing the voltage gradually suppresses overscreening in favor of the crowding of counter-ions in a condensed inner layer near the electrode. This prediction, the ion profiles, and the capacitance-voltage dependence are consistent with recent computer simulations and experiments on room-temperature ionic liquids, using a correlation length of order the ion size.