Symmetrical solid oxide electrolyzer cells (SOECs) with La0.6Sr0.4Co0.2Fe0.8O3 (LSCF)-gadolinium doped ceria (GDC) composite electrodes

Abstract

Scandia (Sc2O3)-stabilized zirconia (ScSZ) electrolyte-supported symmetrical solid oxide electrolyzer cells (SOECs), in which lanthanum strontium cobalt ferrite (LSCF)-gadolinia (Gd2O3)-doped ceria (GDC) composite materials are used as both the cathode and anode, were fabricated and their high temperature steam electrolysis (HTSE) performance was investigated. Current densityvoltage curves were obtained for cells operated in 10% H2O/90% Ar at 750, 800, and 850°C. It was possible to determine the ohmic, cathodic, and anodic contributions to the total overpotential using the three-electrode technique. The HTSE performance was significantly improved in the symmetrical cell with LSCF-GDC electrodes compared to the cell consisting of an Ni-YSZ cathode and LSCF-GDC anode. It was found that the overpotential due to the LSCF-GDC cathode largely decreased and, at a given current density, the total cell voltage decreased, which resulted in the enhanced hydrogen production rate in the symmetrical cell.