Kinetic Monte Carlo simulation of the Yttria Stabilized Zirconia (YSZ) fuel cell cathode

A Kinetic Monte Carlo (KMC) model is developed to simulate non-symmetrically the cathode side of a Yttria Stabilized Zirconia (YSZ) fuel cell, in order to translate experimental, and ultimately theoretical rates into an atomistic model of the cathode. The KMC model consists of a set of several electrochemical reaction rates, adopted from experiments and first-principles calculations. The KMC simulations are used to model these simultaneously occurring events, to determine potential limitations in cathode/YSZ performance. The focus of this work is ionic current density (J), studied as a function of various physical parameters: oxygen partial pressure (PO2), external applied bias voltage (Vext), temperature (T), dopant concentration (mol% Y2O3), relative permittivity (εr) of YSZ, and geometrical features of the YSZ electrolyte. This simple model can be used as a baseline to translate elementary chemical reaction rates into atomistic simulations of working solid oxide fuel cell cathodes, pertinent to the complete set of experimental operating conditions.