Study on Properties of LSGM Electrolyte Made by Tape Casting Method and Applications in SOFC

Solid oxide fuel cell is attracting more attention in recent years for its lower pollution emission and high energy convert efficiency. La0.9Sr0.1Ga0.8Mg0.2O3-δis a new kind of electrolyte for intermediate temperature SOFC. In this paper, La0.9Sr0.1Ga0.8Mg0.2O3-δ(LSGM) was prepared by solid state reaction method and formed by tape casting process to make a planar electrolyte. The appropriate amount of the dispersive was obtained by viscosity test. The densities of sintered samples increase with the increasing sintering temperature. It was found that the relative density of electrolyte can approach the value of 95 % by the isostatic pressing treatment of the green tape. The average thermal expansion coefficient of the LSGM is 11 .4×10-6 /℃at temperature range (200 ~ 1200℃). Measurements of the current-voltage and power-current characteristics of the Hi-Air cell show that the open-circuit voltage is 1.067 V at 800℃, peak current density is 0.56 A·cm -2 and the maximum power output is 0.147 W·cm -2.

SOFC composite electrolyte based on LSGM-8282 and zirconia or doped zirconia from zircon concentrate

The aim of this research is to study zirconia-based electrolyte materials to increase the commercial value of zircon concentrate as a side product of fin mining industries. Synthesis of CaO-Y2O3-ZrO2 （CYZ） and 8mol% Y2O3-ZrO2 （8YSZ） was carried out by solid state reaction. The result shows that ZrO2 presents in tetragonal phase. Doping of Y203 into ZrO2 allows a phase transformation from tetragonal into cubic structure with small percentage of monoclinic phase. Meanwhile, doping of CaO-Y2O3 allows a phase transformation into a single cubic phase. These phase transformations enhance the ionic conductivity of the material. Introduction of 10wt% of LSGM-8282 into CYZ （CYZ-L90：10） allows further improvement of inter-grain contact shown by SEM morphological analysis and leads to the enhancement of ionic conductivity.