Multiscale model for solid oxide fuel cell with electrode containing mixed conducting material

Solid oxide fuel cells (SOFCs) with electrodes that contain mixed conducting materials usually show very different relationships among microstructure parameters, effective electrode characteristics, and detailed working processes from conventional ones. A new multiscale model for SOFCs using mixed conducting materials, such as LSCF or BSCF, was developed. It consisted of a generalized percolation micromodel to obtain the electrode properties from microstructure parameters and a multiphysics single cell model to relate these properties to performance details. Various constraint relationships between the activation overpotential expressions and electric boundaries for SOFC models were collected by analyzing the local electrochemical equilibrium. Finally, taking a typical LSCF-SDC/SDC/Ni-SDC intermediate temperature SOFC as an example, the application of the multiscale model was illustrated. The accuracy of the models was verified by fitting 25 experimental I-V curves reported in literature with a few adjustable parameters; additionally, and several conclusions were drawn from the analysis of simulation results. (c) 2015 American Institute of Chemical Engineers AIChE J, 61: 3786-3803, 2015