Performance of the High Temperature PEM Membrane Electrode Assembly

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 H-2/Air, (ii) MEA lifetime of 12000 h at 0.23 A cm(-2) using dry H-2/Air with an average degradation rate of 9 mu V 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 mu V h(-1) using wet H-2 (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.