Long Term Performance Stability Tests of Ba-Fe-O Infiltrated LSM/YSZ Solid Oxide Fuel Cells under High Steam and High Current

Abstract

Commercial LSM/YSZ cells infiltrated with a solution containing salts with barium and iron cations in a 1:2 ratio were evaluated for their performance and long term stability under high steam, high current and high temperature. Ba-Fe-O-infiltrated cells showed higher performance and lower degradation than the uninfiltrated LSM/YSZ baseline cell, which demonstrates that appropriate nanomaterial infiltration could improve the performance and mitigate the degradation of solid oxide fuel cells under steam. The uninfiltrated baseline cell showed a sharp voltage drop after exposure to steam, while infiltrated LSM/YSZ cells showed a smaller voltage drop that recovered in the first 3-4 h right after exposure to steam. TEM analysis showed no BaFe2O4-infiltrated nanoparticles, the anticipated composition and phase, near the functional layer in cathode before and after testing. However, three different morphologies (nanoribbons, nanoparticles and nanolayers) were found using TEM in the original pore region near the cathode functional layer. EDS showed significant reaction between infiltrated nanomaterials and the LSM/YSZ backbone for the infiltrated cells before and after test. Cells infiltrated with solutions containing different ratios of Ba and Fe cations were also tested to gauge the interaction of Ba and Fe with the LSM/YSZ backbone. Humidity in cathode air can cause an immediate increase in the polarization resistance of LSM/YSZ cathodes, and infiltration is a possible means of mitigating the effects of humidity on LSM/YSZ cathodes.