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Bifunctional oxygen electrocatalysis in alkaline media: addressing the challenge of high activity, durability and cost effectiveness

Friedrich, K. Andreas and Wittmaier, Dennis and Wagner, Norbert and Amin, Hatem M.A. and Baltruschat, Helmut (2016) Bifunctional oxygen electrocatalysis in alkaline media: addressing the challenge of high activity, durability and cost effectiveness. 18th Topical Meeting of the International Society of Electrochemistry, 8.-11. März 2016, Gwangju, Korea.

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Abstract

Oxygen electrochemistry plays a major role in energy conversion and storage devices, particularly in the field of fuel cells, metal-air batteries and water electrolyzers. Especially metal-air batteries have drawn much attention over the last years due to high theoretical energy densities. The major challenge in metal-air batteries is to design and develop economically feasible, earth-abundant, inexpensive, efficient electrocatalysts for the oxygen evolution reaction (OER) as well as the oxygen reduction reaction (ORR). High overpotentials for ORR and OER are reported especially for lithium-air batteries and precious metal electrocatalysts are commonly used. The choice of an alkaline electrolyte widens significantly the material base and the possibility for cost reduction. This contribution discusses the options available and presents a promising bifunctional catalyst that is presently favored at DLR. A wide-range of catalysts was screened and many suitable electrocatalysts and combination of catalyst were identified. In particular, IrO2, Co3O4, Mn3O4 and La0.6Ca0.4CoO3 are most promising bi-functional catalysts. A promising combination is Co3O4 - as the most suitable catalyst for OER - and Ag or Ni which are efficient OER catalysts. Ag/Co3O4 electrodes show high current densities and good long-term stability at reasonable cost and the optimum ratio between the active materials was determined [1-3]. It was shown that the catalyst, electrode thickness, temperature and electrolyte concentration have the highest impact on the current densities, while changing porosity always had a negative impact on the current densities of the investigated electrodes. This contribution discusses the characterization efforts and the investigation of the apparent synergistic effect present in this electrocatalyst mixture.

Item URL in elib:https://elib.dlr.de/109750/
Document Type:Conference or Workshop Item (Speech)
Title:Bifunctional oxygen electrocatalysis in alkaline media: addressing the challenge of high activity, durability and cost effectiveness
Authors:
AuthorsInstitution or Email of AuthorsAuthors ORCID iD
Friedrich, K. Andreasandreas.friedrich (at) dlr.deUNSPECIFIED
Wittmaier, Dennisdennis.wittmaier (at) dlr.deUNSPECIFIED
Wagner, NorbertNorbert.Wagner (at) dlr.deUNSPECIFIED
Amin, Hatem M.A.hatem (at) pc.uni-bonn.deUNSPECIFIED
Baltruschat, Helmutbaltruschat (at) uni-bonn.deUNSPECIFIED
Date:2016
Refereed publication:No
Open Access:No
Gold Open Access:No
In SCOPUS:No
In ISI Web of Science:No
Status:Published
Keywords:alkalische electrocatalyse
Event Title:18th Topical Meeting of the International Society of Electrochemistry
Event Location:Gwangju, Korea
Event Type:international Conference
Event Dates:8.-11. März 2016
Organizer:ISE
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), E - Electrochemical Processes (Batteries) (old)
Location: Stuttgart
Institutes and Institutions:Institute of Engineering Thermodynamics > Electrochemical Energy Technology
Deposited By: Friedrich, Prof.Dr. Kaspar Andreas
Deposited On:19 Dec 2016 16:07
Last Modified:19 Dec 2016 16:07

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