Ni-free single GDC anode deposited on YSZ porous skeleton via hydrothermal treatment for high humidity SOFC operation

A Ni-free anode with a thin, single gadolinium-doped ceria (GDC) layer on a yttria-stabilized zirconia (YSZ) skeleton is proposed to enhance the degradation resistance of GDC as a solid oxide fuel cell (SOFC) anode under high-humidity operation. A thin GDC layer was deposited onto a continuously connected YSZ skeleton via a hydrothermal (HT) treatment. Various YSZ skeleton anodes subjected to identical HT-treatment conditions were operated under a high-humidity condition of 55 %. The anode degradation was found to depend on the morphology of the YSZ skeleton. Notably, the proposed anode configuration exhibited a higher degradation resistance than particle-based GDC–YSZ composite anodes. Postmortem analysis of the YSZ-skeleton GDC anodes revealed cracks in the deposited GDC layer, likely caused by a change in the valence state of GDC. These cracks can be significantly reduced by modifying the morphology of the YSZ skeleton.