Development of LSGM-based solid oxide fuel electrolyte-supported multilayer cells: A comprehensive comparison between symmetrical and asymmetrical cell configurations

Abstract

A multilayer electrolyte of La0.8Sr0.2Ga0.8Mg0.2O3- δ (LSGM) and La0.4Ce0.6O2-δ (LDC) was processed by sequential tape-casting, with optimized heat treatment at 1350 ◦C for 6 h. SEM-EDS and conductivity from EIS confirmed its suitable microstructure and transport properties. Electrodes were deposited on the electrolyte to form two cell types: an asymmetric cell with NiO/Gd0.1Ce0.9O1.95 (Ni-GDC) anode and Sr0.93Ti0.7Fe0.63Ni0.07O3- d (STFN) cathode, and a symmetric cell with Sr0.93Ti0.7Fe0.63Ni0.07O3-d (STFN) as both anode and cathode. The electrochemical performance was assessed with various fuels, showing comparable responses under wet-H2 at 750 ◦C, reaching power densities of 84 mW cm􀀀 2 for the asymmetric cell and 69 mW cm􀀀 2 for the symmetric cell. In a wet H2/CH4 mix, power densities dropped to 61 and 52 mW cm􀀀 2. Over time, the asymmetric cell shows a steady degradation higher than the symmetrical cell. In SOEC mode, both cells showed good reversibility. The STFN cell experienced an immediate current drop in CH4, though Raman analysis showed no carbon deposits on its surface. In dry ammonia, minor microstructural changes appeared in the STFN cell. Still, it maintains robustness with direct hydrogen as fuel, making the STFN symmetrical cell a promising alternative to the state of- the-art Ni-GDC anode.