Correlation Microstructure of Triple Phase Boundary and Crystallinity in SOFC Cells NiO/LSGM/LCM

Abstract

The electrochemical process in the TPB microstructure depends on the conductivity of the SOFC cell constituent materials. Electrolyte and electrode materials must have good conductivity. The crystallinity of an electrolyte can affect its conductivity. In this study, the electrolyte La0.8Sr0.2Ga0.8Mg0.2O3–δ (LSGM) was used and is known to have good conductivity at intermediate temperatures. The single cell of LSGM electrolyte with La0.7Ca0.3MnO3 (LCM) cathode which has high electronic conductivity and NiO anode which has low area-specific resistance (ASR) is expected to produce compatible cells. The production of NiO/LSGM/LCM cells was carried out through the solid-solid phase synthesis method. Microstructural analysis of TPB was performed using SEM-EDS; meanwhile, crystallinity was obtained through XRD analysis. The crystallinity values of NiO, LSGM and LCM cell components above 80% allow the cells to produce high conductivity with a three-phase boundary microstructure from porous electrodes and relatively dense electrolytes which can increase the possibility of gas, ion and electron encounters in the TPB. In SOFC NiO/LSGM/LCM cells, Ni=11.08%; Ca=6.84%; Mn=9.28% and no precipitate is formed at the electrolyte-electrode boundary, so that the electrochemical process on the TPB microstructure could run well.