High-temperature fuel cell with ceria-yttria solid electrolyte

The solid electrolyte of the system CeO2-Y203 exhibited high ionic conductivity, as well as almost unity ionic trans-ference number at 600~176 High current density and electrical power can be obtained from a (CeO2)0.9(YO~.~)0.1 fuel cell at 600~176 La0.6Sr0.4CoO3 was an excellent cathode as compared with Pt electrode. A thin film of stabilized zirconia coated by RF-sputtering is effective in protecting the-anodic surface of ceria-yttria electrolyte from reduction with hydro-gen. The open-circuit voltage of the fuel cell approached the theoretical value with this coating treatment. Solid electrolytes can be used in the construction of high-temperature fuel cells. The oxides most often used as solid electrolyte, CaO- and YOl.~-stabilized zirconia, are less suitable at lower temperatures because of low electri-cal conductivity (1-4). However, the ceria-based oxides generally have higher ionic conductivities than stabilized zirconia, as have been reported for CeO2-CaO (5-7), CeO2-SrO (8-9), and CeO2-rare arth oxide systems (10-13). Takahashi et al. (14-15) attempted to use the solid electro