Long‐Term Testing in Dynamic Mode of HT‐PEMFC H₃PO₄/PBI Celtec‐P Based Membrane Electrode Assemblies for Micro‐CHP Applications

Abstract

High temperature proton exchange membrane fuel cells (HT‐PEMFC) have a promising market in micro‐combined heat and power (μ‐CHP) applications. Operating above 150 °C, they would better cope with return temperatures of typical heating systems than conventional PEMFCs and would allow simplification of system regulations dedicated to failure prevention.Single cell and 500 We HT‐PEMFC stack integrating Celtec P 1000 MEAs were fed with synthetic reformate and air and successfully operated at 160 °C under accelerated typical annual μ‐CHP profile. The single cell was unaffected by 500 h of current cycling while stop/start cycles induced some voltage loss. After 658 h of cumulated operation, stack performance loss was limited at 7.6%: its electrical efficiency (LHV) decreased from 30.6 to 28.3%. Moreover, four initial stop/start cycles weakly impacted its performance, indicating that selected shutdown/restart protocol is convenient for field application. Conversely, after additional start/stop cycles, degradation rate was increased by stop/start cycling and some specific cells (mostly associated with lower initial OCV) exhibited significantly higher degradation rates. Finally, voltage transient evolution during current step exhibits undershoot which magnitude is strongly depends on cell location in the stack: it increased at stack dead‐end and for cells exhibiting highest degradation rates.

High temperature (HT) polymer electrolyte membrane fuel cells (PEMFC) – A review

“…http://repository.uwc.ac.za Moçotéguy et al [123] reported steady-state long term testing for a single cell and a 500 W stack with pure and simulated reformate fuel. They achieved 1105 and 658 h for the single cell and the stack, respectively.…”

“…Moçotéguy et al [123] studied the effect of using reformate fuel reporting a loss of 70e90% of the anode catalyst surface area due to the presence of CO. Moreover, carbon support corrosion and membrane oxidation were reported to be enhanced in HT-PEMs increasing the durability challenge [114].…”

Oxidative Degradation of Polybenzimidazole Membranes as Electrolytes for High Temperature Proton Exchange Membrane Fuel Cells

“…Concerning PBI/phosphoric acid membrane based high temperature PEMFC, a number of durability studies have been performed on both single cells [16][17][18][19][20][21] and stacks [20,21]. Among the identified component failure mechanisms the oxidative degradation of polymer membranes is a key issue [3].…”

Performance of a 1 kW Class Nafion-PTFE Composite Membrane Fuel Cell Stack

“…Bandlamudi et al [19] have studied the properties of 150 W PBI/H 3 PO 4 Gel-Based Polymer Electrolyte Membrane Fuel Cells under the Influence of Reformates. Stacks based on Celtec-P commercial high temperature membranes are also being tested [20]. Bonville et al [21] have studied the effect of scaling up (from 25 cm 2 to 300 cm 2 ) on the cell performance and properties using Ionomem corporations composite membrane based on PTFE, Nafion and phosphotungstic acid at 120…”