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

A LT-PEMFC Stack with Extended Operating Temperature Range up to 120 °C

Ruiu, Tiziana and Dreizler, Andreas and Mitzel, Jens and Gülzow, Erich (2014) A LT-PEMFC Stack with Extended Operating Temperature Range up to 120 °C. International Workshop "Medium Temperature PEM FC - Materials, Stacks and Systems", 02.-03. Dez. 2014, Freiburg im Breisgau, Deutschland.

[img] PDF - Registered users only
7MB

Abstract

Polymer electrolyte membrane fuel cell (PEMFC) stacks for automotive applications operate typically at temperature ranges between –20 °C and 80 °C [1, 2]. On the other hand, specific environmental or operative conditions require the possibility for the stack to operate in a wider temperature range as well. Among the possible scenarios, two cases are of particular relevance: vehicles running in hot areas like deserts, and long uphill drive. In the desert, the ambient temperature is already relatively high, and the cooling system efficiency is reduced due to the smaller temperature difference between stack and environment. During mountain driving, a higher power is required at lower vehicle speed. Consequently, the stack temperature increases, since the cooling of the system through air ventilation is reduced at lower uphill cruising speed. In this work we present the development and characterization of a 30-cell LT-PEMFC stack designed at the German Aerospace Center for operation in an extended temperature range up to 120 °C. The feasibility to temporarily operate the stack at higher temperature would also contribute to the improvement of cooling system components with scaled down dimensions, which in turn would lead to a reduced vehicle weight and thus to an overall lower fuel consumption. The results presented in this contribution include the current-voltage characteristic curves measured on the 30-cell stack and the homogeneity obtained along the cells. Then, the stack behaviour at wide operating temperatures was investigated by performing a series of 20 thermal cycles from 90 to 120 °C, carried out in galvanostatic conditions at a controlled current of 0.5 A/cm2 (approx. 1.5 kW electrical stack power output). The outcome is promising, since only a slight stack voltage decrease was observed during the thermal cycling. Furthermore, the results of a 1200 h long-term stability test are reported, together with an end-of-life electrochemical characterization (cyclic voltammetry and hydrogen crossover measurements) performed on all the cells. The electrochemical analysis can help to identify the main stressors responsible for the observed stack performance loss. Therefore, the catalyst, electrode and membrane degradation are examined by the determination of hydrogen crossover rates and electrochemically active surface areas (EASAs) of each cell. [1] Wu, J.F.; Yuan, X.Z.; Martin, J.J.; Wang, H.J.; Zhang, J.J.; Shen, J.; Wu, S.H.; Merida, W.; J. Power Sources, 2008, 184 (1), 104-119. [2] Schießwohl, E.; von Unwerth, T.; Seyfried, F.; Brüggemann, D.; J. Power Sources, 2009, 193 (1), 107-115.

Item URL in elib:https://elib.dlr.de/93398/
Document Type:Conference or Workshop Item (Poster)
Title:A LT-PEMFC Stack with Extended Operating Temperature Range up to 120 °C
Authors:
AuthorsInstitution or Email of AuthorsAuthors ORCID iD
Ruiu, TizianaTiziana.Ruiu (at) dlr.deUNSPECIFIED
Dreizler, AndreasAndreas.Dreizler (at) dlr.deUNSPECIFIED
Mitzel, JensJens.Mitzel (at) dlr.deUNSPECIFIED
Gülzow, Ericherich.guelzow (at) dlr.deUNSPECIFIED
Date:December 2014
Refereed publication:No
Open Access:No
Gold Open Access:No
In SCOPUS:No
In ISI Web of Science:No
Status:Published
Keywords:PEM fuel cell, PEMFC stack, stack development, automotive application, extended temperature range, thermal cycling, long-term test, end-of-life characterization
Event Title:International Workshop "Medium Temperature PEM FC - Materials, Stacks and Systems"
Event Location:Freiburg im Breisgau, Deutschland
Event Type:Workshop
Event Dates:02.-03. Dez. 2014
Organizer:Fraunhofer-Institut für Solare Energiesysteme ISE
HGF - Research field:Energy
HGF - Program:Efficient Energy Conversion and Use (old)
HGF - Program Themes:Fuel Cells (old)
DLR - Research area:Energy
DLR - Program:E EV - Energy process technology
DLR - Research theme (Project):E - Electrochemical Processes (old)
Location: Stuttgart
Institutes and Institutions:Institute of Engineering Thermodynamics > Electrochemical Energy Technology
Deposited By: Ruiu, Dr. Tiziana
Deposited On:10 Dec 2014 10:55
Last Modified:10 Dec 2014 10:55

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.