Ex-situ and in-situ degradation studies of MEAs used in 1 kW PEM fuel cell stack. (22nd March 2023)

• Record Type: Journal Article
• Authors: Meenakshi, S.; Sonkar, Kapil; Chugh, Sachin; Badhe, Rajesh; Kapur, G.S.; Ramakumar, S.S.V.
• Is Part Of: International journal of hydrogen energy. Volume 48:Number 25(2023)
• Page Start: 9426
• Page End: 9435
• Publication Date: 2023-03-22
• Subjects: PEMFC -- Fuel cell stack -- MEA degradation -- SEM -- MEA post-Mortem; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2022.12.047
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Membrane Electrode Assembly (MEA) in a Polymer Electrolyte Membrane Fuel Cell (PEMFC) plays a fundamental role in the fuel cell system and degradation of it results in substantial performance losses. In this manuscript, the degradation study is carried out on a stack operated MEA of 50 cm 2 area and coupled with 30 individual cells. Three MEAs (fresh, partially degraded and fully degraded) are disassembled from stack and characterized by electrochemical (cyclic voltammetry) and physical methods (TGA, XRD and SEM). TGA with DTG plot showed that MEA assembly majorly decomposes in the temperature range of 320–340 °C for Nafion membrane, 400–430 °C for carbon-supported catalyst and 650–750 °C for carbon-based GDL. In powder XRD characterization, a decrease in electrocatalyst surface area in the degradation sample was observed which also evidenced from the SEM micrographs. The average output voltage of 0.6 V is reduced to 0.42 V in the partially degraded (31.10%) 30th cell due to insufficient fuel for last cell. Catalyst particles are found to migrate outwards and located on the carbon backings was confirmed by ECSA (36% loss). The cell 26th is observed with 0.03 V in the fully degraded (94.43%) condition due to the high pressure in MEA for long-duration which compresses the cathodic side of the assembly resulting in cracking and creating space for the accumulation of water. Graphical abstract: A schematic diagram of degraded MEA, characterization technique and performance analysis. Image 1 Highlights: A degradation study on a stack operated MEA coupled with 30 individual cells. The average output voltage is reduced enormously (94.43%) in fully degraded MEA. The ex-situ characterization techniques for the MEA degradation analysis. TG-DTA showed MEA, catalyst and GDL decomposes with increase in temperature. XRD & SEM studies of degraded MEA showed a decrease in electrocatalyst surface area.