(Digital Presentation) Fabrication and Characterization of 4Sc4YSZ/LSM-4Sc4YSZ Novel Electrode-Supported Half-Cell Composition for Solid Oxide Electrochemical Cells

Abstract

Scandium and Yttrium co-doped ZrO2 (4Sc4YSZ) thin film solid electrolyte has exhibited improved conductivities and phase stability by considering advantages of both Y-doped zirconia (YSZ) and Sc-doped zirconia (ScSZ). To further investigate the promising properties of this co-doped composition, a solid electrolyte thin film of 4Sc4YSZ deposited on a new LSM-4Sc4YSZ composite electrode was conducted. In this study, the effect of pre-sintering temperature (1000°C, 1150°C, and 1300°C) of the LSM-4Sc4YSZ electrode substrate in the deposition of a dense solid electrolyte film was studied. X-ray diffraction (XRD) analysis of all the LSM-4Sc4YSZ composite electrodes revealed distinct phases of rhombohedral LSM and cubic 4Sc4YSZ. Also, the thin film electrolytes exhibited cubic 4Sc4YSZ with calculated lattice parameters of a equal to 5.10 Å, 5.10 Å, and 5.09 Å deposited on the electrode substrate pre-sintered at 1000°C, 1150°C, and 1300°C, respectively. The obtained lattice parameters were comparable with the reference LSM (PDF card no. 000-053-0058) and 4Sc4YSZ (PDF card no. 01-080-4524). Morphological characterization via scanning electron microscopy (SEM) showed that the thin film solid electrolyte with LSM-4Sc4YSZ electrode pre-sintered at 1300°C has a relatively dense microstructure than those with lower pre-sintering electrode temperatures. In addition, the thin film deposited on the 1300°C LSM-4Sc4YSZ obtained the lowest average thickness of 12.81 µm as compared to the 1000°C and 1150°C LSM-4Sc4YSZ with thickness values of 38.32 µm and 27.99 µm, respectively. The electrochemical performance of the fabricated half-cell was analyzed using electrochemical impedance spectroscopy (EIS). The total conductivity, as calculated from the EIS results, of 4Sc4YSZ/LSM-4Sc4YSZ half-cell pre-sintered at 1300°C is 0.0726 S/cm at 700°C under oxygen gas flow environment.