Low-Temperature Fabrication of Oxide Composites for Solid-Oxide Fuel Cells

Composites of yttria-stabilized zirconia (YSZ) with Sr-doped LaCrO3 (LSC) and Sr-doped LaMnO3 (LSM) were prepared by impregnation of a porous YSZ matrix with aqueous solutions of the appropriate metal salts, followed by sintering to various temperatures. XRD measurements showed that perovskite phases formed after sintering at 1073 K, a temperature well below that at which solid-state reactions with YSZ occur. The conductivities of the LSC–YSZ and LSM–YSZ composites prepared in this way were maximized at a sintering temperature of 1373 K for LSC–YSZ and 1523 K for LSM–YSZ, although reasonable conductivities were achieved at much lower temperatures. The conductivities of the two composites increased much more rapidly with the content of the conductive oxide than has been found with conventional composites formed by mixing and sintering the oxide powders. The implications for using this approach to develop novel electrodes for SOFC applications are discussed. Comments Copyright The American Ceramic Society. Reprinted from Journal of the American Ceramic Society, Volume 87, Issue 3, March 2004, pages 331-336. Publisher URL: http://www.ceramicjournal.org/issues/v87n3/pdf/6414.pdf Author(s) Hongpeng He, Yingyi Huang, Juleiga Regal, Marta Boaro, John M. Vohs, and Raymond J. Gorte This journal article is available at ScholarlyCommons: http://repository.upenn.edu/cbe_papers/11 Low-Temperature Fabrication of Oxide Composites for Solid-Oxide Fuel Cells Hongpeng He, Yingyi Huang, Juleiga Regal, Marta Boaro, John M. Vohs, and Raymond J. Gorte* Department of Chemical Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104 Composites of yttria-stabilized zirconia (YSZ) with Sr-doped LaCrO3 (LSC) and Sr-doped LaMnO3 (LSM) were prepared by impregnation of a porous YSZ matrix with aqueous solutions of the appropriate metal salts, followed by sintering to various temperatures. XRD measurements showed that perovskite phases formed after sintering at 1073 K, a temperature well below that at which solid-state reactions with YSZ occur. The conductivities of the LSC–YSZ and LSM–YSZ composites prepared in this way were maximized at a sintering temperature of 1373 K for LSC–YSZ and 1523 K for LSM–YSZ, although reasonable conductivities were achieved at much lower temperatures. The conductivities of the two composites increased much more rapidly with the content of the conductive oxide than has been found with conventional composites formed by mixing and sintering the oxide powders. The implications for using this approach to develop novel electrodes for SOFC applications are discussed.