Material selection in making electrochemical impedance spectroscopy sensor for electrolyte thickness measurement in marine atmosphere

In this work, the material of the electrochemical impedance spectroscopy based (EIS-based) sensor was optimized to achieve in-situ electrolyte layer thickness (hs) monitoring under marine atmosphere. Results show that the sensor made by easy-corrosion materials not only can induce the high-frequency dispersion in EIS curves, but also cause unpredictable evolution of electrolyte conductivity, leading to an inaccurate measurement of hs. Nevertheless, the Ni sensor with a thin and corrosion-resistant oxide film can eliminate those distractions and achieve accurate hs response in dynamic environments. Finally, methods for optimizing EIS-based sensor were summarized, which paves a new way for hs monitoring.