Tsukuba, Japan—Proton-exchange membrane fuel cells (PEMFCs) are a clean power-generation technology that produces no direct carbon dioxide emissions during operation. Their performance and durability depend strongly on effective water management. Monitoring internal conditions during operation is essential to prevent flooding, in which excess liquid water accumulates within the cell, and membrane dry-out, in which the electrolyte membrane loses moisture. Electrochemical impedance spectroscopy (EIS) is a widely used diagnostic technique that characterizes the cell's electrochemical response by applying a small alternating-current signal over a range of frequencies. However, conventional EIS measurements typically involve sequential measurements across a broad frequency range and can take several tens of seconds or longer to complete. This limits their suitability for monitoring rapidly changing operating conditions.
In this study, the researchers reduced both the frequency range and the number of measurement points required for diagnosis. The proposed method uses only six measurement frequencies, compared with 41 in conventional EIS. Comparisons with conventional EIS results showed that a carefully balanced selection of frequencies that capture changes in impedance improved diagnostic accuracy relative to conventional frequency-selection approaches.
The researchers also developed an integrated program combining impedance measurement, data analysis, and operational control. Using resistance parameters derived from impedance data as indicators of the cell's internal condition, the program automatically adjusted operating conditions. This approach enabled the detection and mitigation of electrolyte membrane dry-out and insufficient air supply within the cell.
The proposed method could enable near-real-time diagnosis and control of fuel cell operating conditions without substantially increasing system complexity. Future work will focus on further reducing measurement time and optimizing frequency selection to advance practical diagnostic and control technologies for fuel cell systems.
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This research was conducted under a joint research agreement between the University of Tsukuba and HIOKI E.E. CORPORATION. The ALDAS impedance measurement system used in this research was provided free of charge by HIOKI E.E. CORPORATION.
Title of original paper:
Real-Time PEMFC Diagnosis Using Electrochemical Impedance Spectroscopy Under Limited Data Conditions
Journal:
International Journal of Hydrogen Energy
DOI:
10.1016/j.ijhydene.2026.157623
Assistant Professor AKIMOTO, Yutaro
Institute of Systems and Information Engineering, University of Tsukuba
Institute of Systems and Information Engineering
International Journal of Hydrogen Energy
10.1016/j.ijhydene.2026.157623
Real-time PEMFC diagnosis using electrochemical impedance spectroscopy under limited data conditions
22-Sep-2026