Modeling of Oxygen Chemical Potential Distribution in Solid Oxide Electrolyzer Cells

Abstract

Solid oxide electrolyzer cells (SOEC) often degrade by forming cracks within the electrolyte and delamination along the electrolyte/oxygen electrode interface. It has been shown theoretically and experimentally that transport properties of the electrolyte as well as transport properties of the electrolyte/electrode interfaces affect degradation. This manuscript presents steady state modeling of oxygen chemical potential distribution for SOEC with 8YSZ electrolyte and 8YSZ electrolyte doped to enhance n-type electronic conductivity. It is shown that degradation can be substantially lowered with an increase in electronic conductivity. If ideal electrodes can be developed such that the polarization resistances (charge transfer resistances) and electron transfer resistances at both electrodes are negligible, tendency for degradation can be minimized.