Impact of Load Cycling at High Current Densities on the Degradation Behavior of Membrane-Electrode-Assemblies

Rastedt, Maren; Schonvogel, Dana; Wagner, Peter

doi:10.1149/06403.0741ecst

Cited by 9 publications

(13 citation statements)

References 16 publications

(17 reference statements)

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“…The data from literature correlate with our results at 0.3 A/cm 2 and AST at 0.6 and 1 A/cm 2 . The higher voltage losses can be explained with the higher current densities possibly leading to degradation within the catalyst layer (14), corrosion effects in the carbon support (15) and increasing influence of degradation effects due to acid loss (16). It can therefore not be excluded that also other effects like degradation of electrodes, membrane or GDL (17), which are not investigated here, influence the durability.…”

Section: Fuel Cell Performancementioning

confidence: 99%

Investigation of Phosphoric Acid Distribution in PBI Based HT-PEM Fuel Cells

Pilinski

Rastedt

Wagner³

2015

ECS Trans.

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Phosphoric acid is utilized as electrolyte in high temperature polymer electrolyte (HT-PEM) fuel cells to guarantee proton conduction. Loss of electrolyte may be identified as one of the main degradation aspects. The data presented in this paper focus on a better understanding of the degradation paths caused by acid loss from the membrane-electrode-assembly. Therefore this investigation examined the phosphoric acid distribution in an experimental fuel cell setup. Two operational strategies with long term tests under constant load conditions at 0.3 A/cm² and load cycling tests between high current densities of 0.6 A/cm² and 1.0 A/cm² have been performed. The detection of acid content in the various fuel cell components in combination with imaging methods for the identification of changes in surface structure on the bipolar plates provide good instruments to investigate the influences of acid loss during fuel cell operation.

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Section: Fuel Cell Performancementioning

confidence: 99%

Investigation of Phosphoric Acid Distribution in PBI Based HT-PEM Fuel Cells

Pilinski

Rastedt

Wagner³

2015

ECS Trans.

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“…In the past, it was used to analyse MEAs as well as bipolar plates in detail. These studies showed power losses due to MEA degradation in the form of membrane thinning or formation of pinholes, catalyst layer thinning and formation of cracks or even intrusion of GDL fibres (14)(15)(16). Carbon-based composite bipolar plates are prone to undergo corrosion and thus fail to ensure a proper functionality during critical conditions (17,18).…”

Section: Introductionmentioning

confidence: 99%

Understanding Degradation Phenomena in HT-PEM Fuel Cells Using Micro-Computed Tomography

Schmies¹,

Schonvogel²,

Büsselmann³

et al. 2020

ECS Trans.

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An extended and reliable lifetime of high temperature proton exchange membrane fuel cells is inevitable for the commercialization of this technology in the near future. Therefore, components of the high temperature-proton exchange membrane fuel cell (HT-PEMFC), such as the bipolar plates (BPPs) and the membrane electrode assembly (MEA), are investigated regarding degradation phenomena during constant cell operation with use of contaminated air in the cathode feed. µ-computed tomography (µ-CT) is applied to visualize morphological changes due to this operation and to analyse each component individually on the micro meter scale. The thickness of each MEA layer is determined and correlated to results from electrochemical measurements. Furthermore the open porosity of the bipolar plates is determined and compared to phosphoric acid retention of the cell.

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“…The goal of AST is to assess the durability of membrane electrode assemblies (MEAs) or fuel cell stacks in shorter time while simulating long term operation through application of specially designed operating conditions. HT‐PEMFC load cycling is used as AST by many researchers , , . The effect of load cycling is studied by applying a triangular wave from open circuit voltage (OCV) to 0.5 A cm −2 with 2 s at OCV.…”

Section: Introductionmentioning

confidence: 99%

“…A degradation rate of 44 µV h −1 is observed after 440 h of operation, i.e., 100,000 triangular sweep cycles . DPS and BASF MEA have been investigated under high current density load cycling conditions and found major degradation in catalyst layer but not in membrane . Load cycling tests at three different loads are not uncommon.…”

Section: Introductionmentioning

confidence: 99%

The Effect of Potential Cycling on High Temperature PEM Fuel Cell with Different Flow Field Designs

et al. 2019

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Degradation of phosphoric acid doped polybenzimidazole membrane based fuel cells under accelerated potential cycling conditions is investigated in current study. Three unit cells with identical high temperature membrane electrode assembly were assembled with three different cathode flow field designs. The fuel cell is cycled between 0.5 V and 0.9 V with 3 min dwelling time for each voltage set point. Performance degradation mechanisms associated with differences in cathode flow design are identified. The fuel cell with multiple serpentine design is operated for a maximum of 4,821 potential cycles with only 38.6% of initial performance remaining at the end‐of‐test (EoT), whereas straight and parallel design operated for only 3,188 cycles. The electrochemical characterization studies reveal the cause of observed performance losses from polarization curves. Irrespective of the design type used there are very high activation losses observed which accelerated with accelerated stress tests (AST) testing. The impedance studies reveal high charge transfer resistance related to increased platinum crystal growth on cathode and reduced electrochemical surface area (ECSA) of catalyst. Overall the AST results in irreversible performance loss and severe degradation of the cathode catalyst support and catalyst itself.

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Impact of Load Cycling at High Current Densities on the Degradation Behavior of Membrane-Electrode-Assemblies

Cited by 9 publications

References 16 publications

Investigation of Phosphoric Acid Distribution in PBI Based HT-PEM Fuel Cells

Investigation of Phosphoric Acid Distribution in PBI Based HT-PEM Fuel Cells

Understanding Degradation Phenomena in HT-PEM Fuel Cells Using Micro-Computed Tomography

The Effect of Potential Cycling on High Temperature PEM Fuel Cell with Different Flow Field Designs

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