Effectively regulate NaOH deliquescence rate to prepare yttria-stabilized zirconia self-supported electrolytes for solid oxide cell applications

The high working temperature poses significant challenges to the stability, safety of solid oxide cells (SOCs), and the dry pressing method used to prepare films for electrolyte-supported fuel cells yields smoother but thicker films, which can impair cell performance. Thus, the paper introduces an innovative dry pressing technique for creating a tri-layer structure consisting of NaOH/YSZ/NaOH. By carefully controlling the deliquescence rate of NaOH, the NaOH support layer can be removed efficiently and gently, resulting in a YSZ electrolyte film. The results from the 3D optical profiler show that the average roughness of the YSZ film increased to 2.65 µm and 2.85 µm on each side. The power density and current density of the cell are 0.47 W∙cm⁻² and 1.64 A∙cm⁻² at 850 °C under H₂ and pure CO₂, respectively. These results indicate that the films produced by this novel method are thin, exhibiting favorable roughness and demonstrating high electrochemical performance.