(478a) Philosophy for Interpretation of Impedance Spectra

The interpretation of impedance spectroscopy data requires both a physical insight into the chemistry and physics that govern the system under investigation and an assessment of the error structure of the measurement. Our group has recently published a measurement model computer program that enables both assessing the stochastic and bias errors in a measurement and provides for regression of interpretation models.[1] The program is made available under the GNU General Public License (GPL) 3.0 that makes it free for non-commercial use. Tutorials are provided in the included reference manual and as reference [2]. The object of this presentation is to describe the approach taken by our group for interpretation of impedance data, including error analysis and development of interpretation models.

The need for an interpretation model that accounts for the chemistry and physics of the system is especially urgent, given the proliferation of papers that rely on distribution of relaxation time (DRT) methods. Such DRT models provide a useful intermediate step toward an interpretation model but cannot replace a model that accounts explicitly for the chemistry and physics of the system.

[1] W. Watson and M. E. Orazem, EIS: Measurement Model Program, Version 1.8, ECSArXiv, 2023, https://doi.org/10.1149/osf.io/g2fjm.

[2] M. E. Orazem, “Measurement Model for Analysis of Electrochemical Impedance Data,” (invited paper), Journal of Solid-State Electrochemistry, 28 (2023), 1273-1289.