Invited Talks: Transition Metal Oxides - University Blog Service - The ...

The John B. Goodenough Symposium in Materials Science & Engineering –
In Honor of His 90 th Birthday
The University of Texas at Austin, Austin, Texas
October 26-27, 2012
Novel Cathode and Anode Materials for Solid Oxide Fuel Cells
Matthew West, 1 Daeil Yoon, 2 and Arumugam Manthiram 1,2
1 Department of Chemical Engineering and 2 Materials Science and Engineering Program
The University of Texas at Austin, Austin, TX
Email: manth@austin.utexas.edu Website: http://www.me.utexas.edu/~manthiram
Abstract Body in Space Below:
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Solid oxides fuel cells (SOFCs) offer great promise for future energy production due to their high
efficiencies and fuel flexibility. Despite their benefits, the commercialization of SOFCs is hampered by
severe materials challenges, and there is significant interest in reducing their operating temperatures from
the conventional > 800 o C to an intermediate range of 500 o C – 800 o C and in utilizing hydrocarbon fuels
like natural gas directly instead of hydrogen fuel. We present here the development of new materials and
novel synthesis approaches to address some of these issues. A new series of cathode materials RBaM 4 O 7
(R = rare earth) identified in our group exhibits good catalytic activity with an ideal matching of the
thermal expansion coefficient to that of conventional electrolytes like YSZ. However, the RBaM 4 O 7 series
suffers from long-term stability issues, and attempts to improve stability often come at the expense of
reduced catalytic activity for the oxygen reduction reaction. Through appropriate cationic substitutions
with small amount of dopants in the crystal lattice, we have been able to resolve the stability issues
without significantly sacrificing the electrochemical performance. As for the anode, the oxidation of
hydrocarbon fuels on conventional Ni-YSZ catalyst is accompanied by carbon deposition on Ni, resulting
in a reduction in catalytic activity and overall life expectancy of the cell. To alleviate these problems and
enhance the performance of SOFC anodes, both heterogeneous anode catalysts and new synthesis
techniques for traditional materials are being investigated.