Combined Experimental and Numerical Analysis of Surface-modified Solid Oxide Fuel Cell Cathodes

In this study, the effects of surface modification on the performance of composite solid oxide fuel cell (SOFC) cathodes are investigated through a series of experiments and relevant multi-physics simulations. Experimentally, the LSM/YSZ composite cathodes of commercial fuel cells are surface-treated with various electrocatalysts, and datasets of both polarization curves and electrochemical impedance spectra are collected. The multi-physics simulations consider both charge conservation and species transportation, as well as a multi-step oxygen reduction reaction (ORR) mechanism with parallel pathways. The numerical simulations are developed and then calibrated against data from baseline cells. Based on changes in microstructural properties and rate constants, the performance of the modified fuel cells is then predicted using reaction mechanism parameters recalibrated from experimental data. Analysis is also performed to separate and quantify the effect on cell performance from the changes in microstructural properties and reaction mechanism parameters resulting from surface modification. This study provides insights into the tuning of electrochemical processes when modifying the surface of cathodes and guides further performance improvements.