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2662812 
Journal Article 
The degradation study of Nafion/PTFE composite membrane in PEM fuel cell under accelerated stress tests 
Wu, B; Zhao, M; Shi, W; Liu, W; Liu, J; Xing, D; Yao, Y; Hou, Z; Ming, P; Gu, Jun; Zou, Z 
2014 
Yes 
International Journal of Hydrogen Energy
ISSN: 0360-3199 
39 
26 
14381-14390 
WOS:000341465800054 
Accelerated stress tests (ASTs) were performed to study the degradation mechanism of Nafion/PTFE composite membrane in PEM fuel cell with intensive RH cycling and load cycling. It was recognized that the edge of membrane electrode assembly (MEA) should be carefully treated to prevent the immediate failure for excessive or non-uniform mechanical stress mainly caused by RH cycling in the early period of ASTs. A long accelerated life (over 1000 h) was obtained for MEA with an edge protection and a hot-pressing process along with a low hydrogen permeation current. In addition, the decay of open circuit voltage, the fluoride emission rate (PER) from cathode side and the polarization curves were also monitored during the test. It was verified that the chemical degradation of membrane occurred inevitably caused by radical attack (HO center dot, HO2 center dot and H2O2) due to the intensification of gas mutual permeation. Membrane thinning, Pt particles gathering along the interfaces, even ionomer disappearing at cathode side could be observed from TEM and SEM results. Besides, open circuit voltage under H-2/N-2 atmosphere of MEA was confirmed to be a rapid diagnose tool of membrane physical condition. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. 
Accelerated stress tests; Hydrogen crossover; Nafion/PTFE degradation; Mechanical failure; PEM fuel cell