Enhanced sinterability and electrical performance of Sm2O3 doped CeO2/BaCeO3 electrolytes for intermediate-temperature solid oxide fuel cells through Bi2O3 co-doping

Abstract CeO 2 /BaCeO 3 based electrolytes, one kind of the most promising electrolytes for intermediate-temperature solid oxide fuel cells, usually suffer from poor sinterability and poor electrical performance caused by high sintering temperatures. In this work, Sm 2 O 3 doped CeO 2 /BaCeO 3 electrolytes with Bi 2 O 3 co-doping (90 wt% Ce 0.8 Sm 0.1 Bi 0.1 O 2-δ -10 wt% BaCe 0.8 Sm 0.1 Bi 0.1 O 3-δ , Bi-SDC-BCS) are developed, while Sm 2 O 3 doped CeO 2 /BaCeO 3 electrolytes without Bi 2 O 3 co-doping (90 wt% Ce 0.8 Sm 0.2 O 2-δ -10 wt% BaCe 0.8 Sm 0.2 O 3-δ , BCS-SDC) are taken as a comparison. The electrolyte-supported cells with 75 wt% Ag-25 wt% Ce 0.8 Gd 0.2 O 1.9 as electrodes are assembled and characterized. The results show that the Bi 2 O 3 co-doping allows the sintering temperature to decrease from 1300 °C to 1100 °C, showing a significantly enhanced sinterability. The Bi-SDC-BCS electrolyte sintered at 1100 °C shows a high electrical conductivity (6.08 × 10 −2 S cm −1 at 700 °C in wet air) and a long-term stability, superior to that for most existing electrolytes with the similar chemical constitution. The Bi-SDC-BCS electrolyte-supported single cell shows a peak power density of 352 mW cm −2 at 700 °C using humidified hydrogen as fuel and ambient air as oxidant, almost double of that for the BCS-SDC supported cells. Therefore, the Bi 2 O 3 co-doping into CeO 2 /BaCeO 3 based electrolytes provides a promising way for the development of high performance intermediate-temperature solid oxide fuel cells.