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doctoral thesis
Primjena elektrokemijske impedancijske spektroskopije u dijagnostici degradacije katalitičkog sloja membranskih gorivnih članaka
Split: University of Split, Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture, 2018. urn:nbn:hr:179:680473
Pivac, Ivan
University of Split
Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture
Department of Mechanical Engineering and Naval Architecture

Institutional repository: Repository of the Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture

Cite this document

Pivac, I. (2018). Primjena elektrokemijske impedancijske spektroskopije u dijagnostici degradacije katalitičkog sloja membranskih gorivnih članaka (Doctoral thesis). Split: University of Split, Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture. Retrieved from https://urn.nsk.hr/urn:nbn:hr:179:680473

Pivac, Ivan. "Primjena elektrokemijske impedancijske spektroskopije u dijagnostici degradacije katalitičkog sloja membranskih gorivnih članaka." Doctoral thesis, University of Split, Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture, 2018. https://urn.nsk.hr/urn:nbn:hr:179:680473

Pivac, Ivan. "Primjena elektrokemijske impedancijske spektroskopije u dijagnostici degradacije katalitičkog sloja membranskih gorivnih članaka." Doctoral thesis, University of Split, Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture, 2018. https://urn.nsk.hr/urn:nbn:hr:179:680473

Pivac, I. (2018). 'Primjena elektrokemijske impedancijske spektroskopije u dijagnostici degradacije katalitičkog sloja membranskih gorivnih članaka', Doctoral thesis, University of Split, Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture, accessed 26 December 2024, https://urn.nsk.hr/urn:nbn:hr:179:680473

Pivac I. Primjena elektrokemijske impedancijske spektroskopije u dijagnostici degradacije katalitičkog sloja membranskih gorivnih članaka [Doctoral thesis]. Split: University of Split, Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture; 2018 [cited 2024 December 26] Available at: https://urn.nsk.hr/urn:nbn:hr:179:680473

I. Pivac, "Primjena elektrokemijske impedancijske spektroskopije u dijagnostici degradacije katalitičkog sloja membranskih gorivnih članaka", Doctoral thesis, University of Split, Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture, Split, 2018. Available at: https://urn.nsk.hr/urn:nbn:hr:179:680473

Metadata
TitlePrimjena elektrokemijske impedancijske spektroskopije u dijagnostici degradacije katalitičkog sloja membranskih gorivnih članaka
Title (english)Application of electrochemical impedance spectroscopy in catalyst layer degradation diagnostics of proton exchange membrane fuel cells
AuthorIvan Pivac https://orcid.org/0000-0002-7140-9546
MentorFrano Barbir (mentor)
Committee memberGojmir Radica (predsjednik povjerenstva)
Committee memberGojko Magazinović (član povjerenstva)
Committee memberIvan Tolj (član povjerenstva)
Committee memberJagoda Radošević (član povjerenstva)
Committee memberZoran Mandić (član povjerenstva)
GranterUniversity of Split
Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture
(Department of Mechanical Engineering and Naval Architecture)
Split
Defense date and country2018-10-05, Croatia
Scientific / art field,
discipline and subdiscipline		TECHNICAL SCIENCES
Mechanical Engineering
Process Energy Engineering
Universal decimal classification
(UDC)		621 - Mechanical engineering. Nuclear technology. Machinery
Abstract
U ovoj doktorskoj disertaciji, pisanoj prema tzv. skandinavskom modelu, odnosno u obliku skupa tri objavljena znanstvena rada s preglednim poglavljem, pokazano je da je primjenom elektrokemijske impedancijske spektroskopije moguće dijagnosticirati degradaciju katalitičkog sloja membranskog gorivnog članka, uzrokovanu smanjenjem elektrokemijske aktivne površine, na osnovu usporedbe impedancijskih odzivnih spektara izmjerenih u odreĎenim vremenskim intervalima tijekom njegovog rada. U tu svrhu, razvijen je i novi nadomjesni impedancijski model u obliku električnog ekvivalentnog kruga s 11 elemenata i dvije tzv. rezonantne petlje, sastavljene od paralelno vezanih otpornika, kondenzatora i zavojnice, a koji je primijenjen tijekom ubrzanog degradacijskog testa s cikliranjem katodnog napona. TakoĎer, u području niskih frekvencija impedancijskog odzivnog spektra evidentna je prisutnost induktivne značajke, čiji su mogući uzroci iz literature načelno poopćeni i po prvi puta svrstani u tri grupe mogućih uzroka, i to: popratne kemijske reakcije s meĎuspojevima, utjecaj koncentracije ugljikovog monoksida (ukoliko se ne koriste izrazito čisti reaktanti) i transport vode. Predloţeni model je eksperimentalno verificiran u različitim radnim uvjetima, a obuhvaća i procese odgovorne za induktivnu značajku na niskim frekvencijama, te daje novi doprinos boljem razumijevanju ove pojave, koja je eksperimentalno po prvi put potvrĎena u ovako širokom rasponu gustoća struja, temperatura, tlakova, vlaţnosti i protoka reaktanata.
Abstract (english)
In this doctoral thesis, written in the so-called Scandinavian model as a set of three published scientific papers with an overview chapter, it has been shown that catalyst layer degradation of proton exchange membrane fuel cell, caused by the loss of electrochemical active surface area, is possible to diagnose with electrochemical impedance spectroscopy at certain time steps during the operation. Hence, a novel impedance equivalent circuit model with 11 elements and two so-called resonant loops, comprising of a resistance, capacitance and inductance in parallel, was developed and applied during an accelerated degradation test with cathode voltage cycling. Furthermore, there is an evident presence of the low-frequency inductive phenomenon in Nyquist plot, so three generalized explanations from literature with their variations have been imposed as plausible causes, here for the first time: side reactions with intermediate species, carbon monoxide poisoning (when reactant gases are not used rated ultrapure) and water transport. The proposed model, experimentally verified in various operating conditions, includes the processes responsible for this inductive phenomenon, which was experimentally confirmed for the first time in such a wide range of current densities, temperatures, backpressures, humidities and reactants flows, and gives a new contribution to better understanding of this phenomenon.
Keywords
Keywords (english)
Languagecroatian
URN:NBNurn:nbn:hr:179:680473
Promotion2021
ProjectNumber: IP-2013-11-8700
Title: Upravljanje vodom i toplinom i trajnost membranskih gorivnih članaka
Title: Water and Heat Management and Durability of PEM Fuel Cells
Acronym: PEMFUELCELL
Leader: Frano Barbir
Jurisdiction: Croatia
Funder: HRZZ
Funding stream: IP
ProjectNumber: 325275
Title: System Automation of PEMFCs with Prognostics and Health management for Improved Reliability and Economy
Acronym: SAPPHIRE
Jurisdiction: eu
Funder: EC
Funding stream: FP7
ProjectNumber: 700101
Title: Giantleap Improves Automation of Non-polluting Transportation with Lifetime Extension of Automotive PEM fuel cells
Acronym: Giantleap
Jurisdiction: eu
Funder: EC
Funding stream: H2020
ProjectNumber: DOK-2014-06-4783
Title: Projekt razvoja karijera mladih istraživača - izobrazba novih doktora znanosti
Leader: Frano Barbir
Jurisdiction: Croatia
Funder: HRZZ
Study programmeTitle: Mechanical Engineering
Study programme type: university
Study level: postgraduate
Academic / professional title: doktor/doktorica znanosti, područje tehničkih znanosti, polje strojarstvo (doktor/doktorica znanosti, područje tehničkih znanosti, polje strojarstvo)
Type of resourceText
Extent97 str.
File originBorn digital
Access conditionsAccess restricted to students and staff of home institution
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Created on2021-09-28 12:03:12