Improved performance of a lanthanum strontium manganite–based oxygen electrode for an intermediate-temperature solid oxide electrolysis cell realized via ionic conduction enhancement

Abstract

In order to improve the performance of lanthanum strontium manganite (LSM)-based oxygen electrodes for an intermediate-temperature solid oxide electrolysis cell (SOEC), Ce0.85Sm0.15O2-δ-CuO (SDC-CuO), an oxygen ion conductor, was combined with LSM into a composite material to enhance the ionic conduction of the LSM-based oxygen electrode. The developed oxygen electrode extends the oxygen evolution reaction from the electrolyte/electrode interface to the oxygen electrode, thus improving the performance of the LSM-based oxygen electrode. At 800 ℃ and with 40% relative humidity (RH), the polarization resistance of the LSM/SDC-CuO based SOEC (0.89 Ω cm2) is lower than that of the LSM-based SOEC (1.73 Ω cm2) and LSM/SDC-based SOEC (1.35 Ω cm2) under open circuit voltage, and the current density of the LSM/SDC-CuO based SOEC can reach 0.36 A cm−2 at a voltage of 1.5 V, which is significantly higher than that of the LSM-based SOEC (0.23 A cm−2) and LSM/SDC-based SOEC (0.24 A cm−2). Moreover, the LSM/SDC-CuO based SOEC shows good stability. Therefore, this method is feasible for improving the performance of LSM-based oxygen electrodes in intermediate-temperature SOECs.