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Electrode Development and Characterization for Polymer Electrolyte Fuel Cell with Low to Zero Platinum Loading.

Record Type:	Language materials, manuscript : Monograph/item
Title/Author:	Electrode Development and Characterization for Polymer Electrolyte Fuel Cell with Low to Zero Platinum Loading./
Author:	Komini Babu, Siddharth.
Description:	1 online resource (268 pages)
Notes:	Source: Dissertation Abstracts International, Volume: 78-05(E), Section: B.
Contained By:	Dissertation Abstracts International78-05B(E).
Subject:	Mechanical engineering. -
Online resource:	click for full text (PQDT)
ISBN:	9781369414790

Electrode Development and Characterization for Polymer Electrolyte Fuel Cell with Low to Zero Platinum Loading.
Komini Babu, Siddharth.

Electrode Development and Characterization for Polymer Electrolyte Fuel Cell with Low to Zero Platinum Loading. - 1 online resource (268 pages)

Source: Dissertation Abstracts International, Volume: 78-05(E), Section: B.

Thesis (Ph.D.)

Includes bibliographical references

This item is not available from ProQuest Dissertations & Theses.

This dissertation reports the characterization of polymer electrolyte fuel cell (PEFC) cathodes featuring a Pt group metal-free (PGM-free) catalyst using nano-scale resolution X-ray computed tomography (nano-CT) and morphological analysis. In this work, the pore/solid structure and the Nafion distribution was resolved in three dimensions (3D) using nano-CT for three PGM-free electrodes of varying Nafion loading. The particular PGM-free cathode being studied feature two distinct length scales of interest and was resolved using multi-resolution imaging in nano-CT. The associated transport properties were evaluated from pore/particle-scale simulations within the nano-CT imaged structure. These characterizations are then used to elucidate the microstructural origins of the dramatic changes in fuel cell performance with varying Nafion loading. The results show that this is primarily a result of distinct changes in Nafions spatial distribution. The significant impact of electrode morphology on performance highlights the importance of PGM-free electrode development in concert with efforts to improve catalyst activity and durability. To understand the potential distribution in the thick electrodes we utilize a novel experimental technique to measure the electrolyte potential directly at discrete points across the thickness of the catalyst layer and evaluate the ORR along the thickness of the catalyst layer. Using that technique, the electrolyte potential drop, the through-thickness reaction distribution, and the proton conductivity is measured and correlated with the corresponding Nafion morphology and cell performance.

Electronic reproduction.
Ann Arbor, Mich. :
ProQuest,
2018

Mode of access: World Wide Web

ISBN: 9781369414790Subjects--Topical Terms:

557493
Mechanical engineering.
Index Terms--Genre/Form:

554714
Electronic books.

Electrode Development and Characterization for Polymer Electrolyte Fuel Cell with Low to Zero Platinum Loading.
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100 1 $a Komini Babu, Siddharth. $3 1182244
245 1 0 $a Electrode Development and Characterization for Polymer Electrolyte Fuel Cell with Low to Zero Platinum Loading.
264 0 $c 2016
300 $a 1 online resource (268 pages)
336 $a text $b txt $2 rdacontent
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500 $a Source: Dissertation Abstracts International, Volume: 78-05(E), Section: B.
500 $a Adviser: Shawn Litster.
502 $a Thesis (Ph.D.) $c Carnegie Mellon University $d 2016.
504 $a Includes bibliographical references
506 $a This item is not available from ProQuest Dissertations & Theses.
520 $a This dissertation reports the characterization of polymer electrolyte fuel cell (PEFC) cathodes featuring a Pt group metal-free (PGM-free) catalyst using nano-scale resolution X-ray computed tomography (nano-CT) and morphological analysis. In this work, the pore/solid structure and the Nafion distribution was resolved in three dimensions (3D) using nano-CT for three PGM-free electrodes of varying Nafion loading. The particular PGM-free cathode being studied feature two distinct length scales of interest and was resolved using multi-resolution imaging in nano-CT. The associated transport properties were evaluated from pore/particle-scale simulations within the nano-CT imaged structure. These characterizations are then used to elucidate the microstructural origins of the dramatic changes in fuel cell performance with varying Nafion loading. The results show that this is primarily a result of distinct changes in Nafions spatial distribution. The significant impact of electrode morphology on performance highlights the importance of PGM-free electrode development in concert with efforts to improve catalyst activity and durability. To understand the potential distribution in the thick electrodes we utilize a novel experimental technique to measure the electrolyte potential directly at discrete points across the thickness of the catalyst layer and evaluate the ORR along the thickness of the catalyst layer. Using that technique, the electrolyte potential drop, the through-thickness reaction distribution, and the proton conductivity is measured and correlated with the corresponding Nafion morphology and cell performance.
520 $a At this stage of PGM-free catalyst development, it is also necessary to optimize these thick electrodes along with the catalyst. To address the significant transport losses in thick PGM-free cathodes (ca. > 60 m), we developed a two-dimensional (2D) hierarchical electrode model that resolves the unique structure of the PGM-free electrode. The 2D computational model is employed to correlate the morphology and the electrochemical performance of the PGM-free electrodes. The model is a complete cell, continuum model that includes an agglomerate model representation of the cathode. A unique feature of the approach is the integration of the model with morphology and transport parameter statistics extracted from nano-CT imaging of the electrodes. The model was validated with experimental results of the PGM-free electrode with three levels of Nafion loading. We discuss the sensitivity of the PGM-free catalyst layer on the operating conditions and the morphological parameters to identify improved architectures for PGM-free cathodes. We employ the model to evaluate the targets for the volumetric activity of the catalyst. A notable finding is the impact of the liquid water accumulation in the electrode and the significant performance improvement possible if electrode flooding is mitigated. (Abstract shortened by ProQuest.).
533 $a Electronic reproduction. $b Ann Arbor, Mich. : $c ProQuest, $d 2018
538 $a Mode of access: World Wide Web
650 4 $a Mechanical engineering. $3 557493
650 4 $a Chemical engineering. $3 555952
650 4 $a Materials science. $3 557839
655 7 $a Electronic books. $2 local $3 554714
690 $a 0548
690 $a 0542
690 $a 0794
710 2 $a ProQuest Information and Learning Co. $3 1178819
710 2 $a Carnegie Mellon University. $3 845406
773 0 $t Dissertation Abstracts International $g 78-05B(E).
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=10297440 $z click for full text (PQDT)