Stability of LSCF electrode with GDC interlayer in YSZ-based solid oxide electrolysis cell

摘要

The performance and stability of La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3 - δ) (LSCF) air electrode with Gd_(0.2)Ce_(0.8)O_(2 - δ) (GDC) as an interlayer were tested in the Solid Oxide Electrolysis Cell (SOEC)mode. In order to study the stability and performance of the LSCF air electrode, an 8 mol% Y_2O_3-stabilized zirconia (YSZ) electrolyte supported on a Ni-YSZ fuel electrode was fabricated with and without a GDC interlayer, which was inserted between YSZ and LSCF. To determine the stability of the interlayer and find the optimumfabrication conditions, cellswith the GDC interlayerwere also co-fired at temperatures in the range of 1300-1500 °C and their performance was compared. Single cellswere testedwith an anodic polarization of 800 mA/cm~2 in 80% H_2O + 20%H_2 at 800 °C. The cellwithout an interlayer showed a large increase in Ohmic Area Specific Resistance (ASR) from 0.09 Ωcm~2 to 0.16 Ωcm~2 during 50 h of operation due possibly to the observed delamination between the LSCF and YSZ. On the other hand, the cellwith the interlayer showed a slower increase in Ohmic ASR from0.14 Ωcm~2 to 0.153 Ωcm2 with little delamination. The electrode polarization ASR of the cell with the interlayer also had a similar slower change, from0.16 to 0.185 Ωcm~2, compared to that of the cell without an interlayer, from 0.143 to 0.35 Ωcm~2, after 50 h. The cell co-fired at 1400 °C had the smallest and most stable value of the total ASR for 100 h.