An algorithm for diagnosis of proton exchange membrane fuel cells by electrochemical impedance spectroscopy

•A physics-based model is proposed to investigate experimental impedance diagrams.•A fitting algorithm is developed to diagnose PEMFC stack.•Water flooding is highlighted in the gas diffusion layer and active layer. Further analysis of EIS provides valuable information about reliability and aging of the systems, namely to diagnose water flooding the electrode or membrane drying for Proton Exchange Membrane Fuel Cells (PEMFC). The aim of this study is to propose an electrochemical parameter fitting algorithm. A careful study of the electrochemical kinetics laws allowed us to demonstrate that, as long as both electrodes follow a Tafel behavior, the cathode and anode active layer resistances are strongly correlated. This correlation obviously removes a liberty degree in the model and allow an accurate fitting of the utilized model's electrochemical parameters of our PEMFC stack EIS. The reduced number of liberty degrees eases the convergence of the solution of the model. This algorithm was successfully implemented on different PEMFC stacks technology to investigate the impact of water flooding and the operating points.