The goal of this research is to develop high power output solid oxide fuel cells, essential components of a sustainable energy future. Fuel cells are clean and efficient energy conversion devices, but the cost of solid oxide fuel cells remains high because they must be operated at high temperatures. Key to lowering the temperature of operation is the incorporation of advanced cathode materials into fuel cells, and accordingly is the focus of this work. Success in this arena will be an important first step towards widespread implementation of fuel cells and ultimately, national energy security. Students at all levels will be educated in fuel cell science through their direct participation in the research (graduate and undergraduate students) and through public outreach programs, including a planned fuel cell exhibit at the California Science Center. TECHNICAL DETAILS: The particular material that will be examined is Ba0.5Sr0.5Co0.8Fe0.2O3-. (BSCF) with the objective of combining the demonstrated excellent oxygen activity of this newly developed cathode material with the desirable electrical and mechanical properties of zirconia electrolytes. Because BSCF is chemically reactive with zirconia it has only been possible to use this cathode with less desirable ceria electrolytes. By undertaking a fundamental study of BSCF that provides an atomistic level understanding of the defect chemistry, structural chemistry and oxygen ion transport properties of BSCF, it will be possible to design materials that exhibit the activity of BSCF for oxygen electroreduction, but are unreactive with zirconia. In parallel, efforts will be directed to the development of multi-layer fuel cells in which the desired components (zirconia as an electrolyte and BSCF as the cathode) are separated from one another via a ceria buffer layer.
