Understanding water management and cathode performance in LT-PEMFCs via EIS and DRT diagnostics

Todorovski, Emilija (author), Todorovski, Filip (author), Sekavčnik, Mihael (author), Mori, Mitja (author), Likozar, Blaž (author), Lotrič, Andrej (author)

Low-Temperature Proton Exchange Membrane Fuel Cells (LT-PEMFCs) are key to sustainable energy technologies, but their performance is highly dependent on cathode operating conditions and membrane hydration. This study employs Electrochemical Impedance Spectroscopy (EIS) and the Distribution of Relaxation Times (DRT) to analyze the effects of cathode stoichiometry, temperature, cathode feed composition, and hydration levels on key electrochemical processes. The findings highlight the impact of operational parameters on oxygen reduction reaction (ORR) kinetics, proton transport, and mass transport resistance. DRT analysis identifies flooding and membrane drying as dominant performance-limiting phenomena. Pure oxygen feed mitigates mass transport limitations, while variations in air stoichiometry and temperature influence charge transfer resistance and proton conductivity. This study enhances understanding of LT-PEMFC behavior under diverse conditions and provides insights for optimizing performance and durability. The results provide diagnostic features and fundamental insights that can guide the development of future diagnostic frameworks for improved fuel cell control, enhanced water management strategies, and long-term operational stability.

• Language: English
• Keywords: low-temperature proton exchange membrane fuel cell, LT-PEMFC, electrochemical impedance spectroscopy, EIS, distribution of relaxation times analysis, DRT, fuel cell performance diagnostics
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2026
• Number of pages: 23 str.
• Numbering: Vol. 15, art. 109024
• PID: 20.500.12556/RUL-177813
• UDC: 621.352.6:543.42
• ISSN on article: 2352-4847
• DOI: 10.1016/j.egyr.2025.109024
• COBISS.SI-ID: 263908355
• Publication date in RUL: 08.01.2026

Record is a part of a journal

• Title: Energy reports
• Publisher: Elsevier
• ISSN: 2352-4847
• COBISS.SI-ID: 526119705

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: nizkotemperaturne gorivne celice, protonske izmenjevalne membrane, elektrokemična impedančna spektroskopija, analiza porazdelitev relaksacijskih časov, diagnostika delovanja

Projects

• Funder: ARIS - Slovenian Research and Innovation Agency
• Project number: P2-0401
• Name: Energetsko strojništvo

• Funder: ARIS - Slovenian Research and Innovation Agency
• Project number: P2-0152
• Name: Kemijsko reakcijsko inženirstvo