Scalable and facile fabrication of a dense Ce0.9Gd0.1O2-δ buffer layer for solid oxide fuel cells

Solid oxide fuel cells (SOFCs) are pivotal in addressing global energy and environmental challenges, but their durability and maintenance costs are often limited by interface issues between yttria-stabilized zirconia (YSZ) electrolytes and active cathodes at high operating temperatures. Cerium-based oxides, particularly gadolinium-doped ceria (GDC), have proven effective in mitigating these challenges by acting as efficient buffer layers. In this study, we present a one-step spin-coating method for fabricating a thin, dense GDC buffer layer using GDC nanoparticles. A ∼1 μm thick, high-density (density >80 %) buffer layer is achieved by calcining at 1250 °C, forming a continuous and cohesive interface with the electrolyte. Single cells incorporating this buffer layer exhibit an ohmic resistance of 0.15 Ω cm 2 and achieve a peak power density of 0.81 W cm −2 at 800 °C. Stability is demonstrated by operating the cell at 0.4 A cm −2 and 750 °C for over 200 h with stable performance. Furthermore, the fabrication method has been successfully scaled up for 10 × 10 cm 2 large-area cells, yielding a power output of 31.6 W at 0.7 V at 750 °C. The proposed scalable and cost-effective fabrication technique offers significant potential for the large-scale production of high-performance SOFCs.