Integrated modeling of electrochemical, thermal, and structural behavior in solid oxide electrolysis cells

A three-dimensional (3-D) computational fluid dynamic (CFD) model for solid oxide electrolysis cells (SOECs) has been developed by rigorously accounting for electrochemical reactions, species, charge, and heat transfer phenomena. The CFD model is linked to a finite element method (FEM) solid mechanics model to simultaneously predict electrochemical and structural behaviors of SOECs. First, the coupled CFD and FEM based SOEC model is applied to a 100 cm2 actual cell geometry and validated against the experimental data measured up to 0.4 A/cm2. The model predictions closely align with the experimental data and further reveal key electrochemical and mechanical characteristics of SOEC operations, showing multi-dimensional contours of species, temperature, current density, stress, and deformation. Specifically, this study highlights the imperative to enhance the mechanical attributes and design structure of SOECs. The need arises from the stresses and deformations attributed to thermal expansion, influenced by both the uniformity of temperature distributions and the operating temperature itself. These considerations are vital across various operational contexts. Such understandings will direct advancements in SOEC technology towards greater efficiency and enhanced longevity.