Modelling of CO Poisoning and its Dynamics in HTPEM Fuel Cells

“…Recently, the modelling of CO poisoning in HT-PEMFCs has been the one of the focuses and a handful of publication has been published in the literature. Bergmann et al developed a dynamic two-dimensional non-isothermal model that was experimentally validated with a HT-PEMFC and was useful in predicting the dynamic electrochemical performance in the presence of CO [16]. Jiao et al developed a three-dimensional non-isothermal CO poisoning model, which was beneficial in identifying the optimized operational parameters that would generate good performance in the presence of CO [17].…”

Section: Introductionmentioning

confidence: 98%

Sensitivity analysis of anode overpotential during start-up process of a high temperature proton exchange membrane fuel cell

Kamal

Chan

2015

Electrochimica Acta

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“…[124][125][126] Oxygen and hydrogen have to dissolve in this surface film and reach the electrode by diffusion. Consequently, water is produced in it's liquid state.…”

Section: Journal Of the Electrochemical Society 162 (1) F153-f164 (2mentioning

confidence: 99%

Accelerated Degradation of High-Temperature Polymer Electrolyte Fuel Cells: Discussion and Empirical Modeling

Reimer

Schumacher

Lehnert

2014

J. Electrochem. Soc.

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Accelerated stress tests are commonly applied in order to obtain a prediction of fuel cell life time within a short testing period. The stress test in this work considers a fuel cell which is constantly under load with frequent periods of very high current. Four different cells were operated each with a specific load profile. As a result severe performance degradation was observed in the region of high current densities. A short overview over the phenomena which may contribute to this specific fuel cell degradation is compiled from literature. Based on this overview major degradation modes are identified and combined with a simple polarization curve model. The modeling results allow for two different interpretations. Carbon corrosion reactions can explain the observed effects if cell voltage is assumed as the driving force for degradation. A better fit was obtained by using the overall heat flux as degradation criterion. In this case an increase in local temperature could lead to redistribution and loss of phosphoric acid from the MEA. The expected lifetime of a polymer electrolyte fuel cell (PEFC) ranges from 5 000 h for mobile application to 40 000 h for stationary application.1,2 In order to gain information about time dependent degradation in advance accelerated test protocols are used.3,4 Depending on the design of these tests valuable information about the nature of the main degradation mode under the applied operation conditions can be obtained. Despite the difference in operation conditions for PEFC, HT-PEFC and PAFC the structure and material of the electrodes are almost the same. Consequently, observed degradation phenomena show strong similarities.5 A good description of these phenomena can be found in several review papers 6-13 as well as in at least four books 1,2,14,15 where recent experimental facts and interpretations are summarized. A compact description can also be found in a recent review paper on modeling transport phenomena in PEFCs. 16 The purpose of this paper is to present the results of a specific accelerated degradation test for high temperature polymer electrolyte fuel cells (HT-PEFC) with phosphoric acid doped polybenzimidazole (PBI/H 3 PO 4 ) membranes. The fuel cell is constantly under load with frequent periods of very high current. In order to accelerate degradation effects the fuel cell is operated beyond it's point of maximum power. A simple polarization curve model is used as starting point for the analysis of data. Based on this first analysis a degradation model is proposed which allows for a straightforward physical interpretation. The complexity of degradation effects which occur simultaneousy usually leads to models which either resolve a specific mechanism in depth or describe more general effects. This paper aims at general effects which requires a broader understanding of degradation. In the following it is attempted to provide an overview over the phenomena which may contribute to fuel cell degradation. Based on this overview major degradation modes are identified and ...

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Modelling of CO Poisoning and its Dynamics in HTPEM Fuel Cells

Cited by 52 publications

References 24 publications

Evaluation for sintering of electrocatalysts and its effect on voltage drops in high-temperature proton exchange membrane fuel cells (HT-PEMFC)

Evaluation for sintering of electrocatalysts and its effect on voltage drops in high-temperature proton exchange membrane fuel cells (HT-PEMFC)

Sensitivity analysis of anode overpotential during start-up process of a high temperature proton exchange membrane fuel cell

Accelerated Degradation of High-Temperature Polymer Electrolyte Fuel Cells: Discussion and Empirical Modeling

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