Generalized Distribution of Relaxation Times Analysis for the Characterization of Impedance Spectra
Generalized Distribution of Relaxation Times Analysis for the Characterization of Impedance Spectra
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DOI：
10.3390/batteries5030053
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发表时间：
2019-09-01
期刊：
影响因子：
4
通讯作者：
Danzer, Michael A.
中科院分区：
文献类型：
--
作者：
Danzer, Michael A.
交流阻抗谱是一种在频域分析电化学体系极化行为的通用无损工具。作为标准阻抗谱的扩展和增强，建立了弛豫时间分布（DRT）分析，其中谱从频域转移到时域。DRT有助于通过识别所涉及的极化过程的数量而无需事先假设，并通过分离和量化其单极化贡献来分析复阻抗谱。DRT分析，在文献中介绍，声称是一个无模型的方法表征的电容-电容系统。然而，通常需要基于阻抗模型的数据预处理步骤来从测量的阻抗谱中排除非电阻-电容分量。在这项工作中提出的广义分布的弛豫时间（GDRT）分析是专门复杂的叠加阻抗谱，包括欧姆，电感，电容，和电容电感效应。没有预处理步骤的简化工作流程导致可靠和可再现的DRT分析，满足无模型的假设。GDRT适用于电化学、电学甚至非电学系统的分析。显示了锂离子电池、钒氧化还原液流电池和双层电容器的结果。
Impedance spectroscopy is a universal nondestructive tool for the analysis of the polarization behavior of electrochemical systems in frequency domain. As an extension and enhancement of the standard impedance spectroscopy, the distribution of relaxation times (DRT) analysis was established, where the spectra are transferred from frequency into time domain. The DRT helps to analyze complex impedance spectra by identifying the number of polarization processes involved without prior assumptions and by separating and quantifying their single polarization contributions. The DRT analysis, as introduced in literature, claims to be a model-free approach for the characterization of resistive-capacitive systems. However, a data preprocessing step based on impedance models is often required to exclude non-resistive-capacitive components off the measured impedance spectra. The generalized distribution of relaxation times (GDRT) analysis presented in this work is dedicated to complex superposed impedance spectra that include ohmic, inductive, capacitive, resistive-capacitive, and resistive-inductive effects. The simplified work flow without preprocessing steps leads to a reliable and reproducible DRT analysis that fulfills the assumption of being model-free. The GDRT is applicable for the analysis of electrochemical, electrical, and even for non-electrical systems. Results are shown for a lithium-ion battery, a vanadium redox flow battery, and for a double-layer capacitor.