Scaled up low-temperature SOFCs with symmetrical electrode for applications

In this study, a new type of the Mg_0.4Zn_0.6O/Ce_0.8Sm_0.2O_2-δ (MZSDC) composite electrolyte was synthesized using a co-precipitation method. Large-sized engineering cells have been fabricated and tested to meet the demands of applications. X-ray diffraction scanning electron microscopy and X-ray photoelectron spectroscopy have been employed to characterize the microstructure and the morphology of the synthesized samples. MZSDC is a composite system. X-ray electron spectroscopy shows that Ce (3d) binding energy shifted from high to low and the ratio of Ce³⁺ decreased in comparison to pure CeO₂, due to the doping effect. The doping and composite caused the material to have an excellent electrical property, 0.089 S · cm⁻¹, and device performance, with a maximum power of 16.4 W (648 mW · cm⁻²) achieved at 600 °C for a larger-sized (6 cm × 6 cm × 1 mm) fuel cell. The open circuit voltage and power of the fuel cell only slightly degrades (less than 1 %) after continually tested for 100 h. This is the first report regarding the large size engineering cell performance for using this new composite electrolyte with both excellent performance and low cost.