Effect of Gd-doped ceria interlayer on the stability of solid oxide electrolysis cell

Gd0.2Ce0.8O2-delta (GDC) interlayers, positioned between La0.6Sr0.4Co0.2Fe0.8O3-delta (LSCF) anode (air electrode) and yttria-stabilized zirconia (Y0.16Zr0.84O2-d, YSZ) electrolyte of solid oxide electrolysis cells (SOECs) to prevent mutual reaction, are compared that used either thin-film deposition method to produce dense layers or screen printing to produce porous layers. Two cells with 2 mu pm-thick GDC layers are sputter deposited, one annealed at 1300 degrees C and the other at 1100 degrees C. During SOEC operation with an anodic current density, of -800 mA cm(-2) in 80%H2O + 20% H-2 at 800 degrees C, the two cells show similar Ohmic and polarization resistances at the beginning of measurement, but the cell annealed at 1300 degrees C is more stable after 100 h than the film annealed at 1100 degrees C due to the stability of pinhole free nature of GDC layer. In a third cell with similar to 11 mu m-thick screen-printed GDC layer, GDC is porous and therefore the cell degrades more rapidly during SOEC operation for 100 h than does a cell with similar to 2 mu m-thick, pin-hole free GDC film. The good stability of the cell with dense, pin-hole free GDC thin film is attributed to its blocking of Sr. (C) 2016 Elsevier B.V. All rights reserved.