Study on the possibility of using silver as cathode in protonic ceramic fuel cells

Abstract

Nowadays, the research on micro solid oxide fuel cells allows to preview a new branch of investigation on proton conductors based on lanthanide (Y and rare earths) doped barium zirconate and cerate. These materials exhibit unique properties such as high proton conductivity at temperatures lower than those of the traditional oxide ion conductors. Relevant experimental results for oxide ion conductors show that at intermediate temperatures, the major source of surplus comes from the cathode material. According to a recent report from M. Shang et al.1, this effect is responsible for half of the potential drop at 500ºC of a ceramic fuel cell consisting of BaCe0,7Zr0,1Y0,1Yb0,1O3-y as electrolyte and BaCo0,4Fe0,4Zr0,2O3-y as anode. In this proposal the main goal is to evaluate the possibility of using silver as cathode in a protonic fuel cell. This would allow for establishing the reliability of this type of ceramic fuel cell at intermediate temperatures of operation. To accomplish that, a solid protonic conductor consisting of yttrium-doped barium zirconate cerate will be prepared and characterized. Silver will be used as cathode material. The main parameters to be determined in the half-cells are power density (I x V curves) and open circuit voltage (OCV). Other parameters may be investigated such as the thickness and morphology of the electrode, or the use of a composite cathode. The expected results should give a good insight on the reliability on the use of silver as cathode on protonic fuel cells.1 M. Shang, J. Tong, R. O'Hayre, The Royal Society of Chemistry Advances 3, 15769 (2013). (AU)