High reactive Ce0.8Sm0.2O1.9 powders via a carbonate co-precipitation method as electrolytes for low-temperature solid oxide fuel cells

Homogenous Ce0.8Sm0.2O1.9 (SDC) powders, similar to 12 nm in size, were synthesized via carbonate co-precipitation at low processing temperature with dilute cation and carbonate solutions. The powders showed high sinterability and 98% of theoretical density was obtained when they were sintered at 1100 degrees C for 5 h. The sintered SDC ceramics had high conductivity and low activation energy for conduction. The conductivity was 0.022 S/cm at 600 degrees C and the activation energy was only 0.66 eV. Further, single cells were fabricated using the powders as precursors for the electrolyte and the anode. Maximum power density of 400 mW/cm(2) was achieved at 600 degrees C when humidified hydrogen and air were used as the fuel and the oxidant, respectively. The high fuel cell performance, high conductivity, low activation energy and high sinterability showed that SDC powders precipitated with dilute solutions were promising for application in low-temperature solid oxide fuel cells. (C) 2007 Elsevier B.V. All rights reserved.