Temperature Sensitivity Analysis of Electrochemical Impedance Spectroscopy Results in PEM Fuel Cells

The proton exchange membrane fuel cell (PEMFC) is a promising substitute for classic energy converter machines. However, there are still concerns regarding reliability and durability of PEMFCs, and hence, various modeling methods have been employed. One of the effective methods used for analysis and diagnosis of the fuel cell and other electrochemistry systems is Electrochemical Impedance Spectroscopy (EIS) which has been well established due to its high speed and precision. In this paper, the temperature sensitivity of the EIS results at different current densities obtained for a high temperature PEMFC are studied using electrochemical impedances reported in the literature. The magnitude of different elements in the proposed equivalent circuit for different temperatures and current densities, and root mean squares of deviation of various measurements are extracted. Then, the significance of the variations for different temperatures is examined via t-test. Finally, the minimum temperature change at different currents that can be captured by EIS is determined considering the root mean squares of measured values.