High-temperature proton exchange membrane fuel cells (PEMFCs) are particularly attractive because of the potential benefits of faster electrode kinetics, high tolerance to fuel impurities, no humidification requirements, and simplified system design.¹ The present work focuses on ongoing work based on membrane electrode assemblies (MEAs) for high temperature proton exchange membrane fuel cells. HT-PEMFCs were operated at 160-170 °C using humidified synthetic reformate. We have illustrated that an increase in the pressure of the in-going gases to 2 barG increases - as expected - the performance, E.g. the power density was improved from 0.32 W/cm² at 0 barG to 0.48 W/cm² at 2 barG at 170 °C. More data will be shown at the meeting.

Fig 1: a) IV curves b) dependence of power density on back pressure, operating conditions: backpressure (0.4–2 barG), temperature: 170 °C, and λRef/ λAir (1.3 /2.5)

Continuous operation and more than 290 start stop cycles have been performed in order to study the degradation effects of both continuous operation and of repeated start stops. Start stop cycles led to a degradation of 0.01 mV/cycle.

The durability of HT-PEMFC can now be considered similar to low temperature PEMFC. We have proved more than 15,000 hours in single cells at 0.3 A/cm². The degradation rate is around 4 μV/h for approx. 13,000 hours. Graphs of single cell performance during operation have shown very stable behavior for over 10,000 with an overall degradation of 9 μV/h at a current density of 0.4 A/cm².

Reference

1) O. Jensen, D. Aili, H. A. Hjuler, Q. Li, High Temperature Polymer Electrolyte Membrane Fuel Cells - Approaches, Status and Perspective, ISBN 978-3-319-17081-7; DOI 10.1007/978-3-319-17082-4, Springer International Publishing, New York, 2015.