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Electrochemical Impedance Spectroscopy of Unitized Reversible Fuel Cells (URFC)

Altmann, Sebastian and Wagner, Norbert and Friedrich, K. Andreas (2010) Electrochemical Impedance Spectroscopy of Unitized Reversible Fuel Cells (URFC). 8th International Symposium on Electrochemical Impedance Spectroscopy, 6.-11. Juni 2010 , Carvoeiro, Algarve, Portugal .

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Abstract

Mobile and portable applications normally use secondary batteries for electrical energy supply. Electricity supply from stationary power plants required grid connection which is used for charging the batteries. Unfortunately the specific energy and the energy density of battery storage systems are rather low. Therefore fuel cells are an interesting option to overcome the limitation of energy density. However fuel cells need a continuous supply with fuel and oxidant. At some special applications, like space crafts, autonomous long distance aircrafts or stand-alone power supplies, an external refuelling is not suitable or feasible. In that case, the reactants must be regenerated by water electrolysis which can be realized with a reversible fuel cell system. An important topic for reversible fuel cell systems is the function of so-called bifunctional oxygen electrodes which generally require the combination of favourable properties for both operating modes. In particular, different catalysts for oxygen reduction and for oxygen evolution are needed. U(i) performance curves show the differences in performance and long term stability of the membrane-electrode-assembly but can not give insight into the loss distribution of the cell. Also the information about catalyst activity under the different cell conditions is limited. Therefore impedance spectroscopy is essential for gaining further insight. The impedance spectra of both electrolysis and fuel cell mode have similar frequency features. Therefore the spectra can be fitted with the same equivalent circuit and are directly comparable to each other. The changes of the properties of anode, cathode and membrane associated with the operating mode can be determined.

Item URL in elib:https://elib.dlr.de/66467/
Document Type:Conference or Workshop Item (Poster)
Title:Electrochemical Impedance Spectroscopy of Unitized Reversible Fuel Cells (URFC)
Authors:
AuthorsInstitution or Email of AuthorsAuthors ORCID iD
Altmann, Sebastiansebastian.altmann (at) dlr.deUNSPECIFIED
Wagner, Norbertnorbert.wagner (at) dlr.deUNSPECIFIED
Friedrich, K. Andreasandreas.friedrich (at) dlr.deUNSPECIFIED
Date:June 2010
Open Access:Yes
Gold Open Access:No
In SCOPUS:No
In ISI Web of Science:No
Keywords:unitized regenerative fuel cell, electrolysis, electrochemical impedance spectroscopy, URFC, EIS
Event Title:8th International Symposium on Electrochemical Impedance Spectroscopy
Event Location:Carvoeiro, Algarve, Portugal
Event Type:international Conference
Event Dates:6.-11. Juni 2010
HGF - Research field:Energy
HGF - Program:Efficient Energy Conversion (old)
HGF - Program Themes:E BZ - Fuel cells (old)
DLR - Research area:Energy
DLR - Program:E BZ - Fuel cells
DLR - Research theme (Project):E - Membran-Brennstoffzellen (old)
Location: Stuttgart
Institutes and Institutions:Institute of Engineering Thermodynamics > Electrochemical Energy Technology
Deposited By: Altmann, Sebastian
Deposited On:23 Nov 2010 13:44
Last Modified:31 Jul 2019 19:29

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