Tailoring sintering properties of BaGd 0.3 La 0.7 Co 2 O 6-s steam electrodes for pressurized tubular proton-ceramic electrolysis cells

Abstract

[EN] We herein address manufacturing constraints related to the high-temperature sintering step required for reaching adequate adhesion of oxygen/steam electrodes on proton ceramic electrolytes, particularly in tubular geometry. Incorporating various sintering aids such as Cu, Co, and Ni oxides improves the sinterability of the electrodes and reduces the sintering temperature to 950 degrees C. The ceramic-ceramic composite electrodes based on BaGd 0.3 La 0.7 Co 2 O 6-s (BGLC37) and BaZr 0.7 Ce 0.2 Y 0.1 O 6-s (BZCY) show good and robust electrode-electrolyte adhesion. Composite electrodes were tested under different operation conditions, i.e., temperatures and oxygen partial pressures in symmetrical cell configuration, achieving apparent polarisation resistances below 0.6 Omega & sdot; cm 2 at 600 degrees C in wet air for all the electrodes with sintering aids. Finally, BGLC37/BZCY with 2 wt% of CuO electrodes were successfully applied on pre-reduced and sealed BZCY/Ni-supported tubular half-cells with 16 cm2 active area and measured in electrolysis mode at 600 degrees C and high steam pressure. The results open a route to manufacturing steam electrodes for large-scale electrolysis cells.