Structure and electrical properties of cold sintered 8mol% scandia stabilized zirconia ceramics

Scandia stabilized zirconia (ScSZ) has been considered as a promising electrolyte for solid oxide fuel cell (SOFC), but high sintering temperature was always required to achieve high density and electrical conductivity. Herein, high-performance ScSZ ceramics were prepared at low temperature by using the cold sintering process (CSP) associated with post-heat-treatment (PHT). Firstly, 8 mol% ScSZ nano powder was synthesized by an ethanolassisted two step hydrothermal method. Then, ScSZ ceramics were prepared by using CSP and PHT (CSPPHT). It was found that the relative density of the green body made by CSP at 180 circle C could exceed 70%, which rose to 96.8% after post-heat-treatment at 1200 circle C, higher than that prepared by conventional sintering method at elevated temperature of 1400 circle C with the relative density of 95.4%. Impedance spectra measured at 800 circle C showed the electrical conductivity of ScSZ ceramics prepared by CSP-PHT at 1200 circle C was 0.115 S/cm, prior to that prepared by the CS at 1400 circle C with electrical conductivity of 0.111S/cm. Our results demonstrate that the CSP is a promising method for preparing high performance ScSZ ceramics at reduced temperature.

Automated summary

High-performance ScSZ ceramics were successfully prepared at low temperature using the cold sintering process (CSP) associated with post-heat-treatment (PHT). The relative density and electrical conductivity of the ceramics exceeded those prepared by conventional sintering methods at higher temperatures. This study demonstrates that CSP is a promising method for preparing high-performance ScSZ ceramics at reduced temperature.