CFD model of electrode supported planar solid oxide electrolysis cells

A three-dimensional computational fluid dynamics (CFD) electrochemical model has been created to assess high-temperature electrolysis performance of an electrode supported Solid Oxide Electrolysis Cell (ES-SOEC). Electrode-supported cells represent some of the highest performing solid oxide fuel cells currently under development. The nickel cermet material, which serves as the hydrogen electrode, (anode in the fuel cell mode and the cathode in the electrolysis mode) has a relatively high electronic conductivity and is therefore a logical choice for use as the mechanical support layer in electrode-supported cells. In an anode-supported SOFC, the anode is typically 1 - 1.5 mm in thickness while the electrolyte thickness can be as low as 10 μm. In the fuel-cell mode, steam diffusion away from the functional layer can be readily pressure-driven. In the electrolysis mode, however, it may be preferable to use an oxygen-electrode-supported cell to reduce the concentration overpotential associated with steam diffusion through the thickness of the electrode toward the functional layer. The typical oxygen-side electrode material for the present cells is lanthanum-strontium manganite (LSM) perovskite. Electrode-supported cells are currently being evaluated to determine their performance in the electrolysis mode. This paper will provide 3D CFD results of a computational study of electrode-supported electrolysis cells. The objective of the work is to determine the relative advantages and disadvantages of hydrogen electrode-supported cells versus oxygen electrode-supported cells for operation in the electrolysis mode. Computational results will be validated against experimental data obtained with hydrogen electrode-supported cells.