FIRST PRINCIPLE ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY SIMULATION FOR SOFCs

摘要

Electrochemical impedance spectroscopy (EIS) is a widely utilized experimental method for fundamental mechanism understanding and diagnosis of solid oxide fuel cells (SOFCs). However, EIS experimental results are in general interpreted using equivalent circuit model method. When EIS response induced by very complicated multi-physics processes in SOFC is approximated with a simple equivalent circuit, it will inevitably lead to ambiguity. In this research, first principle EIS simulation method is developed to link multi-physics processes of a button cell to EIS response. The EIS modeling method is validated using experimental data from open literature. The validated EIS model is employed to investigate SOFC performance. Simulation results indicate that EIS response contains a plethora of SOFC behavior information that collectivelycontributed by intrinsic SOFC material property, porous microstructure, as well as operating conditions. The simulation method developed in this research can be potentially utilized for interpretation and de-convolution of experimental EIS results.