Electrochemical Impedance Spectra Measurements and Analysis of Polymer Electrolyte Membrane Electrolysis on Short Stack

Transferring Electrochemical Impedance spectroscopy from fundamental research towards close to application systems allows direct insights into kinetics, transport processes and a state of health indication. Since such stacked systems are optimized for application comprehensive monitoring with reference electrodes is hardly possible. In addition, due to the high power consumption suitable measurement devices are hard to find and the results can only be used to a limited extent. In this work such a test object was set up and tested in different measurement configurations to investigate the reasons for the high noise ratio of the impedance measurement data at more than 200A. It was found that a series circuit consisting of a DC power supply, a high-precision impedance load and the test electrolyser has the least influence on the measurement result of all the methods tested. Finally, the impedance spectra were checked for interpretability using DRT and equivalent circuit fit.