Performance of the High Temperature PEM Membrane Electrode Assembly

Abstract

This communication will provide details on some of the high temperature polymer electrolyte membrane (HT-PEM) membrane-electrode-assembly (MEA) performance targets most recently achieved by Danish Power Systems. These include (i) MEA performances of >0.67 V at 0.2 A cm-2 using dry H2/Air, (ii) MEA lifetime of 12000 h at 0.23 A cm-2 using dry H2/Air with an average degradation rate of 9 µV h-1, and (iii) an integrated 5 kW stack/reformer system using methanol reformate as fuel. Studies using reformate have also led to promising results with an MEA performance of 0.58 V at 0.4 A cm-2 with a degradation rate of 24 µV h-1 using wet H2 (30 mol%)/Air for 500 hours. In addition to reaching these performance benchmarks, a reduction in the standard deviation for MEA performance to <5% has been achieved through efforts aimed at improving the uniformity of the membrane and catalyst layer thicknesses.

Characterization of Membrane Electrode Assemblies for High‐Temperature PEM Fuel Cells

“…These results verified the same tendency as the previously reported in ECS Transactions 11, 15 for the improvement of the MEA and the anode for HT‐PEMFC.…”

“…H 3 PO 4 ‐doped polybenzimidazole (PBI) as the electrolyte membrane has been demonstrated to be the most successful electrolyte system for high‐temperature operation 11, 12. In a recent publication, Kerr et al 11 demonstrated that these membranes operated well with low humidification during a test performed over 10,000 hours.…”

“…H 3 PO 4 ‐doped polybenzimidazole (PBI) as the electrolyte membrane has been demonstrated to be the most successful electrolyte system for high‐temperature operation 11, 12. In a recent publication, Kerr et al 11 demonstrated that these membranes operated well with low humidification during a test performed over 10,000 hours. For membrane electrode assemblies (MEAs) using H 3 PO 4 ‐doped PBI membranes, T. Schmidt and J. Baurmeister evaluated the degradation of the MEA using different poisononous species in the hydrogen streams 8 and applying different operation modes 13.…”

“…In this investigation, start‐stop cycling tests were performed on two different Dapozol® MEAs, using first hydrogen and then synthetic reformate as fuel gas, both with a dew point of 80 °C. Similarly, in a recent ECS Transactions paper 11, the performance and durability of Dapozol® MEAs was investigated and proven for operation under highly humidified fuel gases and constant operation conditions. In addition, the impact of the amount of H 2 S present in the fuel was evaluated over two types of anodes, which were chosen according to results currently shown 14, 15.…”

Corrosion of Carbon Supports, Induced by High-Temperature PEMFC Operating Conditions

“…Moreover the influence of Pt activation on the corrosion of carbon in gas diffusion electrodes was investigated using differential electrochemical mass spectroscopy [5]. In a HT-PEMFC a phosphoric-acid-doped polybenzylimidazole (PBI) membrane for the ionic exchange of protons has been demonstrated to be the most successful electrolyte system for high-temperature operation [6]. Considering this, the evaluation of the corrosion of Pt-based electrocatalysts in two different supports under HT-PEMFC conditions in the potential window between 0.0 V (vs. RHE) and 1.0 V (vs. RHE) will be evaluated in this paper.…”