Research

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 the 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 the industry to assess the quality of raw materials for their electrochemical fabrication lines. We recently published a computer program that will help researchers interpret their impedance measurements.