High performance finite element simulations of infiltrated solid oxide fuel cell cathode microstructures

Abstract

To better understand the effects of infiltration on local electrochemistry and transport in solid oxide fuel cell (SOFCs) electrodes, high-throughput, high-performance finite element simulations are presented within dozens of SOFC cathodes containing synthetically generated nanoscale infiltrates. The computational approach retains the complex microstructural morphologies of cathodes, including those of the three backbone phases (gas, ion, and electron conductors) and the infiltrates (an electron conductor), in meshed domains and computes distributions of local electrochemical quantities within the domains. Simulations were implemented on a supercomputer and converged for 48 distinct microstructural subvolumes, with varying backbone heterogeneities and infiltrate loadings. Analyzing both the ensemble (averaged over subvolumes) and the local (evaluated within subvolumes) performance metrics indicate that infiltration of an electron conductor significantly improves the electrochemical performance of each backbone in a linear fashion with the increase of triple phase boundary content, but the essential ionic transport pathways of the backbone are unchanged. These results shed light into the design and fabrication of optimal electrodes in fuel cells.