Advances in Engineering Advances in Engineering features breaking research judged by Advances in Engineering advisory team to be of key importance in the Engineering field. Papers are selected from over 10,000 published each week from most peer reviewed journals.
J. Electrochem. Soc. 2013, volume 160, issue 8, F840-F847.
Hao Zhang, Herwig Haas, Jingwei Hu, Sumit Kundu, Mike Davis and Carmen Chuy.
Abstract
Voltage cycling is one of the most damaging stressors for automotive PEMFC. Understanding of the effects of voltage cycling on performance degradation is crucial to improve PEMFC durability for automotive applications. This study focuses on the interaction between upper potential limit (UPL) and lower potential limit (LPL) on the stability of PEMFC. A well-defined peak of degradation rate is observed when the LPL is ∼0.8 V with UPL of 1.35 V. A mathematical model was developed to understand the observed relationship between degradation rate and lower potential. Modeling results suggest that when cycling to a lower potential of ∼0.8 V, almost all dissolved Pt migrate from the catalyst layer to the membrane with negligible re-deposition, resulting in a peak of degradation rate at ∼0.8 V. The amount of Pt in the membrane (PITM) measured at end of life (EOL) samples correlates with degradation rates and is in agreement with modeling results.
