A novel low-temperature densification method for the construction of YSZ electrolyte membranes derived from nanoparticles

The elevated sintering temperatures required for conventional yttria stabilized zirconia (YSZ) electrolyte membranes pose a significant limitation to further application. In this study, a novel hydrothermal–vacuum filtration method was applied for membrane construction and a dense and integrated YSZ electrolyte membrane was prepared under a low sintering temperature of 1100 °C. Single phase structured YSZ with grain size less than 10 nm were obtained under optimal hydrothermal conditions. In addition, the lattice distortion induced by the incorporation of Y element stabilized the phase structure of the material and effectively introduced oxygen vacancies. A vacuum filtration route was employed to mitigate nanoparticle agglomeration and enable the stable fabrication of fully dense and homogeneous self-supported electrolyte membranes. The membrane properties obtained using this method were significantly superior to those prepared by conventional dry-pressing. Furthermore, the continuous grain boundaries formed by nanosized particles further enhanced the electrochemical properties of the electrolyte, resulting in a conductivity of 0.02 S/cm at 800 °C for the membrane sintered at 1100 °C. In conclusion, this study provides YSZ electrolyte membranes with outstanding performance and a low-temperature preparation method, both of which demonstrate significant potential for further application in the field of solid oxide cells (SOC).