elib
DLR-Header
DLR-Logo -> http://www.dlr.de
DLR Portal Home | Imprint | Privacy Policy | Contact | Deutsch
Fontsize: [-] Text [+]

Development and Characterization of a LT-PEMFC Stack with an Extended Operating Temperature Range up to 120 °C

Dreizler, Andreas and Ruiu, Tiziana and Mitzel, Jens (2016) Development and Characterization of a LT-PEMFC Stack with an Extended Operating Temperature Range up to 120 °C. 6th Baltic Electrochemistry Conference, 15.-17. Juni 2016, Helsinki, Finnland.

[img] PDF
3MB

Abstract

Nowadays, the operation temperature of a polymer electrolyte fuel cell (PEFC) stack for automotive application is about 80 °C. The presented work concerns the characterization of a 30-cell PEFC stack (2.5 kWel) developed at the German Aerospace Center, designed for operating temperatures up to 120 °C for a limited time span. Short-term operation of the stack at higher temperatures would contribute to the improvement of cooling system components with scaled-down dimensions. This concept helps to reduce the vehicle weight and thus to save fuel. In this contribution we present a proof-of-concept of the feasibility of short-term operation for excess temperature events. For this purpose, the stack behaviour was investigated through a series of 20 temperature cycles from 90 to 120 °C at galvanostatic conditions of 70 A (approx. 0.5 A·cm–2 and 1.5 kWel) and without adaption of the gas dew points. The stack power decreased by 21 ± 1 %, with a fully reversible performance recovery at the end of every thermal cycle (see Fig. 1). The higher irreversible degradation rate under these harsh conditions was attributed to the enhanced mechanical stress, which is also correlated to the cycling of the membrane humidity. Furthermore, the results of a long-term steady-state test of 1200 hours under automotive relevant conditions at 80 °C are presented. An end-of-life characterization of the individual cells helped to identify possible causes for performance losses due to catalyst, electrode and membrane degradation. A reduction of electrochemically active surface areas in some cells was ascribed to a platinum catalyst particle growth. Membrane degradation and carbon corrosion occurred additionally, evidenced by increased high frequency resistances and hydrogen crossover rates of the membranes. As result of carbon corrosion, the hydrophobicity of the carbon-based components decreased, causing water accumulation in individual cells.

Item URL in elib:https://elib.dlr.de/108083/
Document Type:Conference or Workshop Item (Poster)
Title:Development and Characterization of a LT-PEMFC Stack with an Extended Operating Temperature Range up to 120 °C
Authors:
AuthorsInstitution or Email of AuthorsAuthors ORCID iD
Dreizler, Andreasandreas.dreizler (at) dlr.deUNSPECIFIED
Ruiu, Tizianatiziana.ruiu (at) dlr.deUNSPECIFIED
Mitzel, Jensjens.mitzel (at) dlr.deUNSPECIFIED
Date:15 June 2016
Refereed publication:Yes
Open Access:Yes
Gold Open Access:No
In SCOPUS:No
In ISI Web of Science:No
Status:Published
Keywords:Fuel cell, development, characterization, LT-PEMFC, Degradation, thermal cycle, long-term test
Event Title:6th Baltic Electrochemistry Conference
Event Location:Helsinki, Finnland
Event Type:international Conference
Event Dates:15.-17. Juni 2016
HGF - Research field:Energy
HGF - Program:Storage and Cross-linked Infrastructures
HGF - Program Themes:Fuel cells
DLR - Research area:Energy
DLR - Program:E EV - Energy process technology
DLR - Research theme (Project):E - Electrochemical Processes (Fuel Cells) (old)
Location: Stuttgart
Institutes and Institutions:Institute of Engineering Thermodynamics > Electrochemical Energy Technology
Deposited By: Dreizler, Dr. Andreas
Deposited On:22 Nov 2016 09:08
Last Modified:31 Jul 2019 20:05

Repository Staff Only: item control page

Browse
Search
Help & Contact
Information
electronic library is running on EPrints 3.3.12
Copyright © 2008-2017 German Aerospace Center (DLR). All rights reserved.