Spatially Resolved Electrode Diagnostic Technique for Fuel Cell Applications

Carter, Robert N.; Brady, B.; Subramanian, K. G.; Tighe, T. W.; Gasteiger, Hubert A.

doi:10.1149/1.2780956

Cited by 25 publications

(14 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…During operation MEAs undergo several relative humidity changes and can be exposed to harsh conditions like local fuel starvation, which can lead to the observed degradation phenomena. Especially, the observed degradation phenomena of CCL thinning, crack formation and Pt deposition indicate a rise of electrode potential at the cathode due to local fuel starvation [22][23][24]28].…”

Section: Interpretation Of Structural Changesmentioning

confidence: 99%

“…Nonetheless, none of them described degradation due to local fuel starvation, which is considered as a critical failure mode in automotive fuel cell applications [19][20][21]. The importance of this failure mode is emphasized by several studies experimentally investigating local fuel starvation on single cell level by simulating the degradation either by closing parts of the flow field channels [22,23], impregnating the gas diffusion layer [24], reducing hydrogen stoichiometry [25,26], supplying liquid water to the cell [27], or feeding air to the anode [28,29]. Thinning and porosity loss of the cathode catalyst layer (CCL), an increase in the CCL's Pt particle size, and a loss of carbon at the CCL resulting in a performance loss of the cell are commonly found.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Local Fuel Starvation Degradation of an Automotive PEMFC Full Size Stack

et al. 2020

View full text Add to dashboard Cite

The achievement of durability targets is an important challenge for the commercialization of fuel cell electric vehicles (FCEV). In order to meet the requirements, knowledge about the most severe degradation mechanisms of fuel cell stacks under automotive conditions is crucial. In the present work, degradation analysis of an automotive full size stack is performed. Herein, we focus on defects at the cathode catalyst layer and their interrelation including inhomogeneous adhesion of the microporous layer on the catalyst layer, crack formation, cathode catalyst layer thinning and wrinkling of the catalyst coated membrane. In addition, we report linear and circular Pt depositions on top of the cathode catalyst layer, which have to the best of our knowledge not been described in literature yet. For the latter, a degradation mechanism based on liquid water formation, local fuel starvation and current density distribution at the interface between microporous layer and cathode catalyst layer is postulated. Finally, a fast indication for stack degradation is suggested by correlating different degradation phenomena. This improved stack analysis approach allowed us to detect local differences in degradation on both cell and stack level.

show abstract

Section: Interpretation Of Structural Changesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Local Fuel Starvation Degradation of an Automotive PEMFC Full Size Stack

et al. 2020

View full text Add to dashboard Cite

show abstract

“…The N 2 flow was stopped during the entire CV measurement to avoid perturbation of the H 2 partial pressure. 47 The value of ECSA was determined in the same way as already described above for the RDE and CFDE.…”

Section: Measurement Of the Electrochemical Properties Of The Measmentioning

confidence: 99%

Effect of the state of distribution of supported Pt nanoparticles on effective Pt utilization in polymer electrolyte fuel cells

Uchida

Park

Kakinuma

et al. 2013

Phys. Chem. Chem. Phys.

105

View full text Add to dashboard Cite

In polymer electrolyte fuel cells, it is essential to minimize Pt loading, particularly at the cathode, without serious loss of performance. From this point of view, we will report an advanced concept for the design of high performance catalysts and membrane-electrode assemblies (MEAs): first, the evaluation of Pt particle distributions on both the interior and exterior walls of various types of carbon black (CB) particles used as supports with respect to the "effective surface (ES)"; second, control of both size and location of Pt particles by means of a new preparation method (nanocapsule method); and finally, a new evaluation method for the properties of MEAs based on the Pt utilization (UPt), mass activity (MA), and effectiveness of Pt (EfPt), based on the ES concept. The amounts of Pt catalyst particles located in the CB nanopores were directly evaluated using the transmission electron microscopy, scanning electron microscopy and corresponding three-dimensional images. By use of the nanocapsule method and optimization of the ionomer, increased MA and EfPt values for the MEA were achieved. The improvement in the cathode performance can be attributed to the sharp particle-size distribution for Pt and the highly uniform dispersion on the exterior surface of graphitized carbon black (GCB) supports.

show abstract

“…An intensely discussed question is that of the long term stability of Pt containing catalysts with at the same time high catalytic activity [29,30]. The activity and stability of electrode layers can also be studied electrochemically with cyclic voltammetry [31,32]. Future investigations have to link the neutron scattering results with electrochemical investigations in order to achieve a thorough understanding of the structural influences and transport processes from atomic to macroscopic levels.…”

Section: Discussionmentioning

confidence: 99%

Fuel Cell Electrode Characterization Using Neutron Scattering

et al. 2020

View full text Add to dashboard Cite

Electrochemical energy conversion and storage is key for the use of regenerative energies at large scale. A thorough understanding of the individual components, such as the ion conducting membrane and the electrode layers, can be obtained with scattering techniques on atomic to molecular length scales. The largely heterogeneous electrode layers of High-Temperature Polymer Electrolyte Fuel Cells are studied in this work with small- and wide-angle neutron scattering at the same time with the iMATERIA diffractometer at the spallation neutron source at J-PARC, opening a view on structural properties on atomic to mesoscopic length scales. Recent results on the proton mobility from the same samples measured with backscattering spectroscopy are put into relation with the structural findings.

show abstract

Spatially Resolved Electrode Diagnostic Technique for Fuel Cell Applications

Cited by 25 publications

References 19 publications

Local Fuel Starvation Degradation of an Automotive PEMFC Full Size Stack

Local Fuel Starvation Degradation of an Automotive PEMFC Full Size Stack

Effect of the state of distribution of supported Pt nanoparticles on effective Pt utilization in polymer electrolyte fuel cells

Fuel Cell Electrode Characterization Using Neutron Scattering

Contact Info

Product

Resources

About