Improved La0.8Sr0.2MnO3-δ oxygen electrode activity by introducing high oxygen ion conductor oxide for solid oxide steam electrolysis

The limited oxygen ion conductivity of conventional La0.8Sr0.2MnO3-δ (LSM) electrode has hindered the development of high-performance solid oxide cells. To address this issue, the electrode interface structure of LSM electrode is regulated by incorporating oxides with high oxygen ion conductivity. Specifically, the addition of Dy and Y co-doped Bi2O3-δ oxide (DBY) with a conductivity of 0.34 S cm−1 at 700 °C, which is almost 9 and 20 times higher than conventional SDC and YSZ oxides, has found to substantially reduce the electrode sintering temperature and enhance the transport ability of ion and electron at the interface. As a result, the interface polarization resistance of the LSM/DBY composite electrode is as low as 0.096 Ω cm2 at 700 °C. Finally, a solid oxide cell equipped with an LSM/DBY electrode attains a high power density of 1.78 Wcm−2 in fuel cell mode at 800 °C and 3%H2O–H2, as well as a current density of −1.58 Acm−2 in electrolysis mode under 1.50 V and 50% H2O–H2 condition.