Effect of the thickness of sputtered gadolinia-doped ceria as a cathodic interlayer in solid oxide fuel cells

Taehyun Park, Yoon Ho Lee, Gu Young Cho, Sanghoon Ji, Joonho Park, Ikwhang Chang, Suk Won Cha


Sputtered gadolinia-doped ceria (GDC) film was introduced as the cathodic interlayer between an yttriastabilized zirconia (YSZ) pellet and a Pt cathode in solid oxide fuel cells (SOFCs). The fuel cells with none, 50, 100 and 150 nmthick GDC interlayers were fabricated to investigate the effect of the thickness of the GDC interlayer. The performances of the SOFCswith the 100 and 150 nmthick GDC interlayers operated at 450 °C showed the highest performance. Through electrochemical impedance analysis, it was visualized that the GDC interlayer significantly reduced the faradaic resistance of the SOFC. The degradation of the performance from the increased ohmic resistance by adding the GDC interlayerwas negligible. Fromthe topographical images scanned by atomic force microscope, it was observed that the 50 nm thick GDC interlayer did not perfectly cover the surface of the YSZ pellet, resulting in incomplete performance enhancement by the sputtered GDC.