Highly dense and ultrathin gadolinia-doped ceria interlayer for enhanced performance of large-area anode-supported solid oxide fuel cell

The fabrication of a highly dense and ultrathin Gd doped ceria (GDC) interlayer on a large-area, porous electrolyte-coated planar anode support using vacuum slurry coating is studied for application in solid oxide fuel cells (SOFCs). The electrolyte-coated planar anode support body is fabricated by tape casting and pre-sintering is performed at 1100, 1150, and 1200 ​°C. The GDC interlayer is coated onto the pre-sintered electrolyte-coated anode support using a vacuum slurry coating process with different immersion times (30–60 ​s). A highly dense and ultrathin GDC interlayer with a thickness of 1.48 ​μm is produced after co-sintering at 1400 ​°C. The 1200 ​°C pre-sintered electrolyte-coated anode support showed a thin and highly dense GDC interlayer which is attributed to a lower shrinkage difference between the coated GDC interlayer and pre-sintered body. The electrochemical performance of a vacuum slurry-coated GDC interlayer cell is 38 ​% higher compared to that of the screen-printed GDC-coated cell at 700 ​°C due to the greatly reduced Ohmic and electrode polarization resistances. The considerable improvement in the performance is attributed to the ultrahigh GDC density which has prevented the secondary phase formation between the cathode and electrolyte. This study presents the economical, scalable, and reproducible process for the fabrication of highly robust GDC interlayer for the large-area planar anode-supported SOFCs.