Researchers at the University of Illinois at Chicago (UIC) and Argonne National Laboratory have received a $475,000 National Science Foundation award to develop solid oxide fuel cells (SOFCs) that operate at intermediate temperatures (IT) of between 600–800°C by making thin layers of controlled chemical composition in one reactor so the interfaces are also controlled, thereby vastly improving the chances of creating a viable IT SOFC.
SOFCs oxidize fuels by electrochemical conversion to create electricity, using a solid oxide as the electrolyte between an anode and cathode circuit. While their small size and solid state are attractive attributes, their higher operating temperatures—currently as high as 1,000 °C—can be a major drawback. Intermediate temperature (IT) SOFCs require new materials and alternate structures to achieve high electrochemical efficiency at lower temperatures.
Christos Takoudis, Gregory Jursich, Robert Klie, and Alan Zdunek from the University of Illinois at Chicago, along with Jeffrey Miller from Argonne National Laboratories in Illinois will engineer the SOFCs with smaller thickness for each of the anode, cathode and electrolyte layers and with precise control over the chemical compositions of the layers.
Using a novel atomic layer deposition/chemical vapor deposition (ALD/CVD) hybrid reactor currently installed at the Advanced Photon Source at Argonne Labs to create complex metal oxides with thicknesses varying from near bulk-like micron layers to atomic-like nanometer layers, the investigators plant to develop and control the thermal and electrochemical properties of the IT-SOFCs to achieve successful reduced temperature operability.
To determine what has been chemically crafted, the researchers will use X-ray absorption and X-ray diffraction during ALD/CVD deposition, reaction and thermal transformation conditions to better understand and control the synthesis process of the final micro-nano material structures. The teams says that this novel experimental set-up will allow hitherto unavailable understanding of electrochemical, catalytic and thermal property trends from the macroscopic to microscopic chemistries. In addition, the equipment will allow the investigators to fabricate all three components within the same reactor as one deposition process, resulting in atomically well-defined interfacial regions and evaluation of the three components as an integral system.
We’re trying to come up with new materials and processes to make these fuel cells very efficient at lower temperatures. Material and design demands for higher temperatures are much more severe and require additional precautionary measures.—Christos Takoudis
A key research focus is how well the anode, electrolyte and cathode work at interface junctions and what contamination problems exist, if any.
As dimensions shrink, it becomes even more important, because the actual contact area is much greater with respect to the total volume than it is in bigger systems.—Christos Takoudis