Performance and stability of co-synthesized Sm_0.5Sr_0.5CoO₃-Ce_0.8Sm_0.2O_1.9 composite oxygen electrode for solid oxide electrolysis cells

The performance and stability of the Sm_0.5Sr_0.5CoO₃-Ce_0.8Sm_0.2O_1.9 composite with a weight ratio of 7:3 (SSC-SDC73) were studied and evaluated as oxygen electrode of high temperature solid oxide electrolysis cells (SOECs). The co-synthesized SSC-SDC73 oxygen electrode exhibited better electrochemical activity and stability than that of physically mixed one for the oxygen oxidation reaction. The effect of anodic polarization current on the co-synthesized SSC-SDC73 oxygen electrode was further investigated under the relative low and high currents at 800 °C in air, respectively. The obtained results demonstrated that co-synthesized SSC-SDC73 oxygen electrode exhibited a better stability under low anodic polarization current. While a higher anodic polarization current could promote the slight agglomerate and delamination of the electrode. Therefore, the polarization current is a key operating parameter for SSC-SDC73 oxygen electrode under the SOEC operation conditions.