Identification of polarization characteristics and analysis of low-frequency inductive impedance phenomena in proton exchange membrane electrolyzer

Advancing efficient and durable green hydrogen production requires precise diagnosis of proton exchange membrane water electrolyzer (PEMWE) performance. This study introduces an innovative, integrated analytical framework that synergizes galvanostatic electrochemical impedance spectroscopy with distribution of relaxation times and equivalent circuit models (GEIS-DRT-ECM). This approach overcomes the empirical limitations of conventional methods, enabling the systematic deconvolution and quantification of key polarization processes under diverse operating conditions. Through DRT-based analysis, five distinct polarization processes were identified from the EIS spectra: proton transport impedance at the anode and cathode (P1, P2), charge transfer impedance at the cathode and anode (P3, P4), and mass transport impedance (P5). Additionally, variations in operating parameters significantly affect both the number and intensity of characteristic peaks. Furthermore, a novel ECM was developed to accurately decode the low-frequency inductive response, allowing the assessment of metal cation contamination and its impact on PEMWE degradation. Collectively, the robust diagnostic platform is critical for optimizing PEMWE operation compatible with intermittent renewable energy sources and for accelerating the development of advanced, cost-effective green hydrogen technologies.