Performance decay of proton-exchange membrane fuel cells under open circuit conditions induced by membrane decomposition

Sugawara, Seiho; Maruyama, Takao; Nagahara, Yoshiki; Kocha, Shyam S.; Shinohra, Kazuhiko; Tsujita, Kohei; Mitsushima, Shigenori; Ota, Ken Ichiro

doi:10.1016/j.jpowsour.2008.11.021

Cited by 78 publications

(56 citation statements)

References 55 publications

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“…The deleterious effect of the adsorption of various anions on active ORR sites of Pt is well established in the literature. 51,54,[58][59][60][61][62][63][64][65] Since the measured SA of poly-Pt will be impacted by the impurities in the electrolyte, we evaluated perchloric acid from 8 sources/suppliers as listed in Experimental section; the criterion for down-selections was based on the magnitude of the measured poly-Pt SA. Table I is ) and Veritas Doubly Distilled that resulted in the highest SA, the other five grades resulted in SAs that were comparable as shown in Fig.…”

Section: Resultsmentioning

confidence: 99%

Oxygen Reduction Reaction Measurements on Platinum Electrocatalysts Utilizing Rotating Disk Electrode Technique

Shinozaki

Zack

Richards

et al. 2015

J. Electrochem. Soc.

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290

346

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The rotating disk electrode (RDE) technique is being extensively used as a screening tool to estimate the activity of novel PEMFC electrocatalysts synthesized in lab-scale (mg) quantities. Discrepancies in measured activity attributable to glassware and electrolyte impurity levels, as well as conditioning, protocols and corrections are prevalent in the literature. The electrochemical response to a broad spectrum of commercially sourced perchloric acid and the effect of acid molarity on impurity levels and solution resistance were also assessed. Our findings reveal that an area specific activity (SA) exceeding 2.0 mA/cm 2 (20 mV/s, 25 • C, 100 kPa, 0.1 M HClO 4 ) for polished poly-Pt is an indicator of impurity levels that do not impede the accurate measurement of the ORR activity of Pt based catalysts. After exploring various conditioning protocols to approach maximum utilization of the electrochemical area (ECA) and peak ORR activity without introducing catalyst degradation, an investigation of measurement protocols for ECA and ORR activity was conducted. Down-selected protocols were based on the criteria of reproducibility, duration of experiments, impurity effects and magnitude of pseudo-capacitive background correction. Statistical reproducibility of ORR activity for poly-Pt and Pt supported on high surface area carbon was demonstrated.

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Section: Resultsmentioning

confidence: 99%

Oxygen Reduction Reaction Measurements on Platinum Electrocatalysts Utilizing Rotating Disk Electrode Technique

Shinozaki

Zack

Richards

et al. 2015

J. Electrochem. Soc.

Self Cite

290

346

View full text Add to dashboard Cite

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“…The contaminants might be identical to either the harmful species generated on the catalyst surface as a result of H 2 and O 2 reaction [15,16], or the membrane decomposition products. Recently, Sugawara et al [1] also reported a water condensation method as an alternative recovery operation for flushing out possible contaminants, and were able to partially recover fuel cell performance decay through flushing of the adsorbing anions generated during OC operation. From this research, it can be deduced that the hazardous species generated on the catalyst sites contributed to initiating the PEM degradation, and, conversely, the PEM degradation products also acted as contaminants for the catalyst, which proves that the PEM and CL degradation processes contribute to each other during OC operation.…”

Section: CVmentioning

confidence: 99%

“…In practice, the degradation of fuel cell components in a low-load operating mode is one of the most crucial deterrents that affect a fuel cell's durability, especially for automotive fuel cell systems. The relevant circumstances, which include open circuit (OC) conditions without electric load and idle conditions with low current density [1], occur frequently over the entire lifetime of a PEM fuel cell.…”

Section: Introductionmentioning

confidence: 99%

Effects of open-circuit operation on membrane and catalyst layer degradation in proton exchange membrane fuel cells

Zhang

Yuan

Hin

et al. 2010

Journal of Power Sources

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Durability issues have been attracting a great deal of attention in hydrogen/air proton exchange membrane (PEM) fuel cell research. In the present work, membrane electrode assembly (MEA) degradation under open circuit (OC) conditions was carried out for more than 250 h. By means of several on-line electrochemical measurements, the performance of the fuel cell was analysed at different times during the degradation process. The results indicate that structural changes in the PEM and catalyst layers (CLs) are the main reasons for the decline in performance during OC operation. The results also show that degradation due to platinum oxidation or catalyst contamination can be partially recovered by a subsequent potential cycling process, whereas the same cycling process cannot recover the membrane degradation.Crown

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“…Similar to the zero electric load condition of OC operation, another effective stressor is close to OC operation, which utilizes so called idle conditions with a very low current density running on the cell. In practice, the degradation of fuel cell components under OC or idle conditions is one of the most crucial deterrents that affect a fuel cell's durability, especially for automotive fuel cell systems [17], because these two circumstances occur frequently over the entire lifetime of a PEM fuel cell. For example, the idle time may amount to several thousand hours over the entire lifetime of the fuel cell [18].…”

Section: Introductionmentioning

confidence: 99%

Degradation of a polymer exchange membrane fuel cell stack with Nafion® membranes of different thicknesses: Part I. In situ diagnosis

Yuan

Zhang

Wang

et al. 2010

Journal of Power Sources

102

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This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. The durability of polymer exchange membrane (PEM) fuel cells, under a wide range of operational conditions, has been attracting intensive attention, as durability is one of the largest barriers for commercialization of this promising technology. In the present work, membrane electrode assembly (MEA) degradation of a four-cell stack with Nafion membranes of different thicknesses, including N117, N115, NR212, and NR211, was carried out for 1000 h under idle conditions. By means of several on-line electrochemical measurements, the performance of the individual cells was analyzed at different times during the degradation process. The results indicate that the cells with thinner membranes have a lower open circuit voltage (OCV) due to the higher fuel crossover. Before degradation, the thickness of the membranes correlates with performance of the cell. However, with the advancement of degradation, the performance of cells with thinner membranes degraded much faster than those with thicker membranes, especially after 800 h of operation. The fast performance degradation for thinner membranes is evident by a dramatic increase in hydrogen crossover indicating membrane thinning or pinhole formation. Crown

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Performance decay of proton-exchange membrane fuel cells under open circuit conditions induced by membrane decomposition

Cited by 78 publications

References 55 publications

Oxygen Reduction Reaction Measurements on Platinum Electrocatalysts Utilizing Rotating Disk Electrode Technique

Oxygen Reduction Reaction Measurements on Platinum Electrocatalysts Utilizing Rotating Disk Electrode Technique

Effects of open-circuit operation on membrane and catalyst layer degradation in proton exchange membrane fuel cells

Degradation of a polymer exchange membrane fuel cell stack with Nafion® membranes of different thicknesses: Part I. In situ diagnosis

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