Abstract
Proper clamping pressure is needed to guarantee the gas-tightness of PEMFC assembly and to enhance the contacts between components. Nevertheless, excessive mechanical load can deteriorate the cell performance, particularly by reducing the porosity and the mass transfer properties of the Gas Diffusion Layers (GDLs). In this study, the global performance of a 225 cm2 PEMFC assembly under mechanical stress (0.35–2 MPa) is investigated through Electrochemical Impedance Spectroscopy (EIS) as a complement to cell voltage monitoring and polarisation curves carried out previously. The analysis relies on the evolution, against mechanical compression, of the high and low frequency resistances, as well as the arc sizes of the EIS spectra. The measurements emphasise that mechanical loading primarily decreases ohmic losses, and they also highlight the importance of harmful physical phenomena at high frequencies. Ex-situ measurements (through-plane resistance of GDL) and in-situ results (high frequency resistance) show a similar reduction trend observed with increasing mechanical compression.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.