Intermediate temperature steam electrolysis using LaGaO3-based electrolyte

Steam electrolysis was studied by using La0.9Sr0.1Ga0.8Mg0.2O3 (LSGM) oxide electrolyte and it was found that H2 formation rate obeys the Faradayʹs law suggesting that the transport number of oxide ion in LSGM under electrolysis condition is unity. Ni–Fe alloy cathode is highly active to electrolysis of steam, however, insertion of Ni-SDC (1:9) layer between Ni–Fe cathode and LSGM electrolyte is further effective for improving the electrolysis performance of the cell. The current density at 1.8 V was achieved values of 314 and 254 mA/cm2 at 1073 and 873 K, respectively. The improved current density by Ni-SDC is mainly assigned to a decreased cathodic overpotential. The electrolysis efficiency which ignored the inserted heat energy, was calculated based on the formed H2 amount and the consumed electric energy, and it is found that the estimated efficiency was higher than 70%.