Effect of Ce0.85Sm0.15O2-δ–CuO interlayer on the performance of intermediate-temperature solid oxide electrolysis cell

Abstract To improve the performance of intermediate-temperature solid oxide electrolysis cells (IT-SOECs) based on the Ce0.85Sm0.15O2-δ (SDC) interlayer, a transition metal oxide (CuO) was added to the interlayer to enhance its oxygen ion conduction, and thereby, reduce the oxygen electrode polarization resistance of the SOEC. The performance of SOECs based on the SDC–CuO interlayers was studied. The experimental results showed that SDC–CuO interlayers sintered for 10 h at 1050 °C, 1075 °C, and 1100 °C (referred to as SDC–CuO-1050, SDC–CuO-1075, and SDC–CuO-1100, respectively) are highly dense. This indicates that the preparation temperature of a dense SDC interlayer can be reduced by compositing it with CuO. The performances of SOECs based on the SDC–CuO-1050, SDC–CuO-1075, and SDC–CuO-1100 interlayers were higher than that of the SOEC based on the SDC interlayer. This indicates that oxygen ions can move faster from the SDC–CuO-1050, SDC–CuO-1075, and SDC–CuO-1100 interlayers to the oxygen electrode to participate in the electrochemical reaction. This reduces the polarization resistance of oxygen electrodes and improves the performance of the SOECs. The performance of the SOEC based on the SDC–CuO-1050 interlayer is the highest, indicating that sintering at 1050 °C for 10 h is the best condition to prepare high-performance SDC–CuO interlayers. Thus, this study provides an effective method for improving the performance of IT-SOEC based on SDC interlayer.