Ultralow Degradation Rates in HT-PEM Fuel Cells

One of the major advantages of polybenzimidazole (PBI) based high temperature polymer electrolyte (HT-PEM) fuel cells compared to the low temperature representatives of this type of fuel cell technology is the higher tolerance against impurities like CO. Nevertheless lifetime and durability are still an issue. In this work, an improvement in degradation rates and therefore an extension of lifetime of HT-PEM fuel cells will be presented. Extended long term tests have been performed at different facilities under similar test conditions. After 3,000 h of operation, an average degradation rate of -1.7 µV/h has been achieved. One of the tests is still under operation; this MEA already reached a lifetime more than 9,000 hours with an actual degradation rate of -3 µV/h.