CPE analysis by local electrochemical impedance spectroscopy
CPE analysis by local electrochemical impedance spectroscopy
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DOI：
10.1016/j.electacta.2005.02.128
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发表时间：
2006-01-20
影响因子：
6.6
通讯作者：
Tribollet, B
中科院分区：
文献类型：
--
作者：
Jorcin, JB;Orazem, ME;Tribollet, B
恒相元件 (CPE) 广泛用于等效电路中以拟合实验阻抗数据。 CPE 行为通常归因于分布式表面反应性、表面不均匀性、粗糙度或分形几何形状、电极孔隙率以及与电极几何形状相关的电流和电势分布。在这项工作中，考虑了不同的电化学系统，这些系统显示出整体阻抗在高频范围内的 CPE 依赖性。研究发现局部电化学阻抗谱可以提供一种很好的方法来评估局部变化对全局阻抗测量中 CPE 行为的影响。可以很容易地观察到 2D 和 3D 分布之间的分离。在二维分布（AZ91 镁合金）的情况下，CPE 行为的起源是与圆盘电极的几何形状相关的高频电阻的分布，而电容与位置无关。对于铝电极，CPE 行为可归因于 3D 和 2D 分布的组合。几何分布在电化学系统的阻抗响应中发挥着重要作用，并且这些分布可以导致 CPE 行为。 (c) 2005 Elsevier Ltd. 保留所有权利。
Constant-phase elements (CPE) are used extensively in equivalent electrical circuits for fitting of experimental impedance data. The CPE behavior is generally attributed to distributed surface reactivity, surface inhomogeneity, roughness or fractal geometry, electrode porosity, and to current and potential distributions associated with electrode geometry. In this work, different electrochemical systems showing the CPE dependence in the high-frequency range for the overall impedance were considered. Local electrochemical impedance spectroscopy was found to provide a good means for assessing the influence of local variations on the CPE behavior seen in global impedance measurements. A separation between 2D and 3D distributions could be easily observed. In the case of a 2D distribution (AZ91 Mg alloy), the origin of the CPE behavior was the distribution of high-frequency resistance associated with the geometry of the disk electrode whereas, the capacitance was independent of position. In the case of the aluminium electrode, the CPE behavior could be attributed to a combination of 3D and 2D distributions. Geometric distributions can play a significant role in the impedance response of electrochemical systems, and these distributions can lead to CPE behavior. (c) 2005 Elsevier Ltd. All rights reserved.