A rapid analytical assessment tool for three dimensional electrode microstructural networks with geometric sensitivity

•Analytical approach to assess 3-D electrode microstructural networks.•Studied 3-D microstructures in Sr2Fe1.5Mo0.5O6−δ, a redox stable SOFC electrode.•Significant reduction in memory requirements and computational time was observed.•Predictions validated to experimental measurements and detailed 3-D finite element simulations.

Electrochemical fin theory is applied to the microstructural analysis of Sr2Fe1.5Mo0.5O6−δ (SFM), a redox stable solid oxide fuel cell (SOFC) electrode. The electrode microstructure is imaged by X-ray nanotomography, then partitioned into a network of resistive components with distinct geometric characteristics. The network is analyzed using an analytical electrochemical fin network model. The resulting predictions of electrode performance are compared to predictions made using three-dimensional finite element simulations of charge transport with surface electrochemical reactions in the imaged microstructure. For a representative subvolume of the structure, the electrochemical fin and finite element models provide comparable predictions. Analysis of larger representative volume elements extracted from the X-ray nanotomography data demonstrates good agreement with experimental measurements of the electrodes analyzed. Finally, advantages of applying the analytical electrochemical fin network models to real microstructures are addressed, particularly with respect to significant reduction in memory requirements and computational time. The use of the electrochemical fin theory is able to rapidly analyze real microstructures with microstructural details that are comparable to finite element and lattice Boltzmann methods, but at volume sizes that finite element and lattice Boltzmann methods were not able to perform due to limits in memory and computational time.