Application of the Transmission Line EIS Model to Fuel Cell Catalyst Layer Durability
Pourquoi ce travail est dans la base
Une base qui oublie comment elle a trouvé un travail ne peut pas être vérifiée. Voici les voies qui ont admis celui-ci.
Notice bibliographique
Résumé
Typical catalyst layers (CL) employed in PEM fuel cells are composed of a carbon supported Pt catalyst bound together with an ionomer, most often Nafion. Both the carbon support and ionomer play a crucial role in optimizing the catalyst utilization by proving electronic and ionic conductive pathways, respectively, without hindering gas transport. Upon fuel cell operation, the catalyst layer can degrade by one of 3 primary pathways: Loss of Pt surfaces area through Pt dissolution/Ostwald ripening Corrosion of the carbon support Degradation of the ionomer network The contribution of each of these pathways depends upon CL compositions as well as the cell operating conditions. The extent of degradation is normally monitored in situ by cyclic voltammetry (CV) by measuring changes in the electrochemically active surface area (ECSA) of Pt. However, CV is limited in that it can only conclusively confirm the presence of the first pathway. Contributions from the other 2 pathways are typically confirmed by post mortem analysis of the CL. We have recently reported that the addition of periodic electrochemical impedance spectroscopy (EIS) measurements to an accelerated degradation testing protocol (ADTP) allows one to clearly diagnose the presence of the other 2 degradation pathways. By performing EIS under conditions where the transmission line model is valid, the presence of carbon corrosion can be clearly detected by a characteristic shift in the EIS response over time [1], as shown in Figure 1. Likewise, the loss of ionic conductivity can also be observed through a unique change in a typical capacitance plot [2]. Our methodology has since been extended and further validated by studying the stability of numerous commercial and in-house prepared catalysts using with different carbon supports. In this presentation, we will describe how EIS can be incorporated into almost any ADTP protocol and how changes in the EIS response can be used for in situ diagnosis of degradation pathways that can be attributed to CL components. In particular we will describe how the presence and absence of both Pt and C impacts the degradation processes and subsequently the EIS response [3]. Furthermore, we will also demonstrate how by carefully selecting the DC bias potential one can quantitatively monitor ECSA degradation (pathway 1) with EIS (instead of CV) by using monitoring the pseudo-capacitance associated with H-adsorption (Figure 2) [4]. References F. S. Saleh and E. B. Easton, J. Electrochem. Soc. , 159 , B546 (2012). J. I. Eastcott and E. B. Easton, J. Power Sources , 245 , 487 (2014). F. S. Saleh and E. B. Easton, J. Power Sources , 246 , 392 (2014). O. Reid, F. S. Saleh, and E. B. Easton, Electrochim. Acta , 114 , 278 (2013)
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découle