Research Summary

Many of my contributions have been in the area of impedance spectroscopy, a powerful analytic tool employed in all aspects of electrochemistry, including energy devices, corrosion, and sensors. My group developed a model for multicomponent diffusion impedance that shows how coupling of faradaic and charging processes causes frequency dispersion for all systems influenced by mass transfer. This work provided, for the first time, a quantitative assessment of a phenomenon proposed in the mid-1960s. In collaboration with my French and Italian colleagues, our group developed a novel method to extract physically meaningful information from impedance data affected by frequency dispersion, a problem that had been unresolved since it was identified in the 1940s. Our power-law model has proven useful for oxides on metals, for human skin, and for water uptake in coatings. It is now implemented in industry to assess quality of raw materials for their electrochemical fabrication lines. We recently published a computer program that will help researchers interpret their impedance measurements.

 Research Narrative

My group developed a model for multicomponent diffusion impedance that shows how coupling of faradaic and charging processes causes frequency dispersion for all systems influenced by mass transfer. This work provided, for the first time, a quantitative assessment of a phenomenon first proposed by Paul Delahay in the mid-1960s.

• S-L. Wu, M. E. Orazem, B. Tribollet, and V. Vivier, “The Impedance Response of Rotating Disk Electrodes,” Journal of Electroanalytical Chemistry, 737 (2015), 11-22. LINK
• S-L. Wu, M. E. Orazem, B. Tribollet, and V. Vivier, “The Influence of Coupled Faradaic and Charging Currents on Impedance Spectroscopy,” Electrochimica Acta, 131 (2014), 3-12. LINK

In collaboration with my French and Italian colleagues, our group developed a novel method to extract physically meaningful information from impedance data affected by frequency dispersion, a problem that had been unresolved since it was identified in the 1940s. Our power-law model, first published in 2010, has proven useful for oxides on metals, for human skin, and for water uptake in coatings. It is now implemented by TDK (formerly Hutchinson Technology) to assess quality of raw materials for their electrochemical fabrication lines.

• C. You, A. Titov, B. H. Kim, and M. E. Orazem, “Impedance Measurements on QLED Devices: Analysis of High-Frequency Loop in Terms of Material Properties,” invited paper, Journal of Solid State Electrochemistry, 24 (2020), 3083-3090. LINK
• Y.-M. Chen, A. S. Nguyen, M. E. Orazem, B. Tribollet, N. Pébère, M. Musiani, and V. Vivier, “Identification of Resistivity Distributions in Dielectric Layers by Measurement Model Analysis of Impedance Spectroscopy,” Electrochimica Acta, 219 (2016), 312-320. LINK
• M. E. Orazem, B. Tribollet, V. Vivier, S. Marcelin, N. Pébère, A. L. Bunge, E. A. White, D. P. Riemer, I. Frateur, and M. Musiani, “Dielectric Properties of Materials showing Constant-Phase Element (CPE) Impedance Response,” Journal of The Electrochemical Society, 160 (2013), C215-C225. LINK
• B. Hirschorn, M. E. Orazem, B. Tribollet, V. Vivier, I. Frateur, and M. Musiani, “Constant-Phase-Element Behavior Caused by Resistivity Distributions in Films: 1. Theory,” Journal of The Electrochemical Society, 157 (2010) C452-C457. LINK

The measurement model was developed in our group the early 1990s to quantify the error structure of electrochemical impedance spectroscopy measurements. The work is an extension of an approach, developed for optical characterizations, to spectra associated with electrochemical impedance measurements. Our programs were used in house for the past 30 years, and an updated version has now been released to the scientific community under a license that makes it free for noncommercial use. We have demonstrated that the measurement model can also provide a means to assess the capacitance of electrodes subject to frequency dispersion.

• W. Watson and M. E. Orazem, “EIS: Measurement Model Program,” ECSArXiv, 2020, https://ecsarxiv.org/kze9x/.
• H. Liao, W. Watson, A. Dizon, B. Tribollet, V. Vivier, and M. E. Orazem, “Physical Properties Obtained from Measurement Model Analysis of Impedance Measurements,” Electrochimica Acta, 354 (2020), 136747. LINK
• P. Agarwal, M. E. Orazem, and L. H. García-Rubio, “Measurement Models for Electrochemical Impedance Spectroscopy: 1. Demonstration of Applicability,” Journal of The Electrochemical Society, 139 (1992), 1917-1927. LINK

The interpretation of frequency dispersion in impedance measurements has been an ongoing problem for the past 50 years. Our group demonstrated that such behavior may be attributed to distributions of time constants, either through a film or along the surface of an electrode. Contribution #2 represents the solution to the problem for a distribution through a film perpendicular to the electrode surface. Our work on distributions along the electrode surface suggests that electrode roughness, capacitance distributions, and rate constant distributions are unlikely to provide an explanation for frequency dispersion that are often seen to encompass a broad range of frequency. We interpreted the frequency dispersion in terms of an ohmic impedance.

• O. Gharbi, A. Dizon, M. E. Orazem, M. T.T. Tran, B. Tribollet, and V. Vivier, “From Frequency Dispersion to Ohmic Impedance: A New Insight on The High-Frequency Impedance Analysis of Electrochemical Systems,” Electrochimica Acta, 320 (2019), 134609. LINK
• M. E. Orazem, Y.-M. Chen, and C. L. Alexander, “Corrosion Detection in Structural Tendons,” US Patent No. 9,829,452 B2, Issued: November 28, 2017. PDF
• C. L. Alexander, B. Tribollet, and M. E. Orazem, “Influence of Micrometric-Scale Electrode Heterogeneity on Electrochemical Impedance Spectroscopy,” Electrochimica Acta, 201 (2016), 374-379. LINK
• J. Jorcin, M. E. Orazem, N. Pébère, and B. Tribollet, “CPE Analysis by Local Electrochemical Impedance Spectroscopy,” Electrochimica Acta, 51 (2006), 1473-1479. LINK

Under support from Mosaic, a major Florida company, we developed a fully continuous method for electrokinetic dewatering of dilute waste streams resulting from phosphate mining operations. The company currently stores the suspensions in clay settling ponds that take 25-50 years to achieve consolidation. The technology developed in this project can greatly reduce the environmental impact of mining operations.

• M. E. Orazem and R. Kong, “Electrokinetic Dewatering of Phosphatic Clay Suspensions,” U.S. Patent No. 10,486,108 B2, Issued: Nov. 22, 2019. PDF
• M. E. Orazem, R. Kong, S. Moghaddam, H. Lai, D. Yu, Y. Huang, and D. Bloomquist, “Continuous Electrokinetic Dewatering of Phosphatic Clay Suspensions,” U.S. Patent No. 10,315,165 B2, Issued: Jun. 11, 2019. PDF
• M. E. Orazem and A. Dizon, “Device for Efficient Continuous Electrokinetic Dewatering of Phosphatic Clay Suspensions,” U.S. Patent Application 2019/0127256 A1 May 2, 2019. PDF
• A. Dizon and M. E. Orazem, “Advances and Challenges of Electrokinetic Dewatering of Clays and Soils,” invited paper, Current Opinion in Electrochemistry, 22 (2020) 17-24. LINK