Effects of proton-conducting electrolyte microstructure on the performance of electrolyte-supported solid oxide fuel cells
Three kinds of proton-conducting electrolyte powder BaCe0.8Sm0.2O2.9 (BCS) with different microstructures are synthesized by three different methods: EDTA-citrate method, EDTA-citrate and ball-milling method, and hydrothermal method. X-ray diffraction and scanning electron microscopy are used to investigate the microstructure and morphology of the BCS powders, and electrochemical measurements and impedance spectroscopy are employed to analyze electrical characteristics of the electrolyte-supported solid oxide fuel cells (SOFCs). It is found that the performance of electrolyte-supported SOFCs strongly depends upon the electrolyte microstructure, which is dominated by the synthesis methods. At the operating temperature of 650 °C, the highest SOFC performance (80 mW/cm2) is obtained from the cell with nanostructured proton conducting electrolyte powder synthesized by the hydrothermal method, while the lowest performance (17 mW/cm2) is the cell with the largest grain powder synthesized by the EDTA-citrate method without ball-milling treatment.