Effect of Y0.25Bi0.75O1.5 electrolyte composite on the performance of La1.4Bi0.1Sr0.5Ni0.5Mn0.5O4þd air electrode for solid oxide electrolysis cells

In the present study, in order to further improve the electrochemical performance of La1.4Bi0.1Sr0.5Ni0.5Mn0.5O4+d (LBSNM) air electrode for solid oxide electrolysis cells (SOECs), Y0.25Bi0.75O1.5 (YSB) electrolyte composite for LBSNM (LBSNM-xYSB, x = 0, 20, 30, 40 wt%) air electrode is systematically investigated to obtain the optimal performance. The effect of sintering temperature on the microstructure and polarization impedance (Rp) of the air electrode is also examined. Among the samples with different YSB contents, the half cell with LBSNM-30YSB composite electrode exhibits the lowest Rp value of about 0.041 U cm2 at 800 degrees C, which is 88.1% lower than that of LBSNM electrode. The single cell with LBSNM30YSB air electrode obtains a current density as high as 1188 mA cm-2 at 800 degrees C and 1.4 V for 70%CO2+30%CO feed gas; this value is 46.5% higher than that of LBSNM under the same conditions. No degradation is observed after the single cell is operated continuously at 1.4 V for 50 h at 800 degrees C, indicating its relatively good long-term stability. Thus, LBSNM30YSB is a potential air electrode for SOECs.(c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.