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

Abstract The microwave sintering method is found to have advantages over the conventional thermal treatment method for preparing BaZr 0.1 Ce 0.7 Y 0.2 O 3-δ 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 BaZr 0.1 Ce 0.7 Y 0.2 O 3-δ powder at a relatively low temperature (900 °C) with a short dwell time of 1 h, while the same pure phase can only be formed at 1000 °C in an electric furnace. Importantly, the grain size for the microwave prepared BaZr 0.1 Ce 0.7 Y 0.2 O 3-δ powder is much smaller than that of the conventionally thermal treated BaZr 0.1 Ce 0.7 Y 0.2 O 3-δ 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 × 10−3 S cm−1 delivers a power output of 791 mW cm−2 at 700 °C. Highlights • Microwave sintering was used to prepare BaZr 0.1 Ce 0.7 Y 0.2 O 3-δ powder at 900 °C. • Microwave sintering allowed a small grain size of 25 nm for the as-prepared powder. • Microwave prepared BaZr 0.1 Ce 0.7 Y 0.2 O 3-δ powder benefited the electrolyte preparation. • High electrolyte conductivity and desirable fuel cell performance were achieved. [ABSTRACT FROM AUTHOR]