Design and Preparation of SOFC Unit Cells Using Scandia-Stabilized Zirconia Electrolyte for Intermediate Temperature Operation

A solid oxide fuel cell unit cell based on a scandia-stabilized zirconia (ScSZ) electrolyte for intermediate temperature operation (below 650°C) was manufactured as an anode-supported unit cell via uniaxial pressing, dip-coating, and screen printing methods. The nanocomposite powders used to improve anode performance were synthesized by selectively coating nanosized NiO particles on ScSZ core particles by the Pechini process. Anode-supported ScSZ electrolytes were fabricated by dip-coating a slurry of Ni-ScSZ composite powder on a die-pressed anode pellet, followed by dip-coating of the electrolyte ScSZ slurry. The lanthanum strontium manganite (LSM)-ScSZ cathode and the samarium doped ceria (SDC) interlayer were formed on the anode-supported ScSZ electrolyte using the screen printing method. The lanthanum strontium cobalt ferrite (LSCF)–SDC cathode was also formed on the SDC interlayer. The anode-supported unit cells designed and prepared in this study had a power density of 0.61 W cm−2 at 800°C. Moreover, the unit cell structured by the functional layer and the LSCF cathode demonstrated excellent performance with a power density of 0.49 W cm−2 at 650°C.