Stability and Reactivity of LSGM Electrolytes With Nickel-Based Ceramic Cathodes

Abstract

The surface of La0.9Sr0.1Ga0.8Mg0.2O3−δ (LSGM 9182) has been examined through the use of secondary-ion mass spectrometry before and after surface modification by mechanical polishing. It was found that the cation stoichiometry varied at the surface in both cases. The effect of this change on the performance of the cathode material La2NiO4+δ was assessed through ac impedance spectroscopy of symmetrical cells prepared by depositing La2NiO4+δ on the surface of pellets of La0.9Sr0.1Ga0.8Mg0.2O3−δ. An improvement in the cathode performance of these cells at temperatures above 500°C was found on electrolytes with elevated levels of strontium and magnesium at the surface.