Enabling durable hydrogen production and preventing the catastrophic delamination in the solid oxide electrolysis cells by infiltrating SrFe2O4-δ solutions into LSM/YSZ -based air electrode

Abstract

Solid oxide cells with La0.8Sr0.2MnO3/yttria-stabilized zirconia (LSM/YSZ) air electrodes exhibit accelerated performance degradation during electrolysis of hydrogen production. Under galvanic mode with a current density of 0.5 A/cm2, baseline electrolysis cells exhibit a rapid increase in resistance upon 200 h of operation and become utterly delaminated after 350 h at 800 °C. To prevent such catastrophic delamination, SrFe2O4-δ solutions are infiltrated into the LSM/YSZ air electrode of as-fabricated cell. Under the identical operation condition, SrFe2O4-δ infiltrated cells exhibit performance enhancement manifested by an immediate decrease in electrolysis operation voltage and reduction of both series and polarization resistance and sustainability of 900 h continuous electrolysis operation without delamination. Nanostructure examination reveals active interaction of the SrFe2O4-δ infiltrate with cells after calcination, Fe diffusion into the LSM backbones, and formation of nanoparticles on the surface of the backbones. During electrolysis, the nanoparticles maintain intact morphology and constant particle size, while there is continuous cation exchange between the nanoparticles and the backbone. The nanostructure origin of the increased electrolysis performance, reduced resistance, and increased durability induced by infiltration are discussed. The present study demonstrates a feasible and viable approach to preventing electrode delamination while increasing the durability of hydrogen production for electrolysis cells.