Fabrication of high-performance proton-conducting electrolytes from microwave prepared ultrafine powders for solid oxide fuel cells

摘要

The microwave sintering method is found to have advantages over the conventional thermal treatment method for preparing BaZr0.1Ce0.7Y0.2O3-delta powder. Comparing with the conventional thermal treatment, the microwave sintering method allows the solid material to be self-heated, enabling the formation of pure phase BaZr0.1Ce0.7Y0.2O3-delta powder at a relatively low temperature (900 degrees C) with a short dwell time of 1 h, while the same pure phase can only be formed at 1000 degrees C in an electric furnace. Importantly, the grain size for the microwave prepared BaZr0.1Ce0.7Y0.2O3-delta powder is much smaller than that of the conventionally thermal treated BaZr0.1Ce0.7Y0.2O3-delta powder. The small powder grain size is found to be beneficial for the densification and grain growth of the resultant electrolyte membrane during the electrolyte sintering procedure. A fuel cell fabricated using this electrolyte membrane with a conductivity of 7 x 10(-3)S cm(-1) delivers a power output of 791 mW cm(2) at 700 degrees C.