Effect of GDC interlayer on the degradation of solid oxide fuel cell cathode during accelerated current load cycling

Abstract

The effect of gadolinium-doped ceria (GDC) interlayer on the cathode degradation of solid oxide fuel cell (SOFC) during accelerated current load cycling was investigated. The SOFC half-cells with and without GDC interlayer were prepared and tested under 400 rapid current load cycles. The half-cells consisted of lanthanum strontium cobalt ferrite (LSCF)-GDC composite cathode, GDC interlayer, scandia ceria stabilized zirconia (ScCeSZ) electrolyte, and platinum anode as a counter electrode. The area specific resistance (ASR) of the half-cell was measured every 10 current load cycles. The ASR of the half-cell without GDC interlayer greatly increased with current load cycling, which is attributed to the delamination of the cathode/electrolyte interface due to SrZrO3 formation during sintering. On the other hand, the half-cell with GDC interlayer showed a minute increase in ASR during current load cycling due to very small elemental diffusion across the GDC interlayer/electrolyte interface. These results mean that the GDC interlayer produced high resistance to cathode degradation under the current load cycling due to effective suppression of Sr diffusion across the interface.