Modeling and optimization of electrode structure design for solid oxide fuel cell

A comprehensive steady-state model is developed to investigate the effects of electrode structure on the performance of solid oxide fuel cell, considering detailed heat and mass transfer processes, as well as electronic and ionic charge transport. The percolation theory is used to evaluate the effective transport properties in electrode. The uniform and non-uniform distributions of electronic/ionic conducting materials in anode/cathode function layer (AFL/CFL) are comprehensively compared. The effects of function layer thickness and particle sizes are found to be different in anode and cathode. The optimal AFL thickness is increased with the increment of particle sizes. The results show that the optimal AFL thickness ranges from 5 μm to 30 μm with relatively small particle sizes (<0.4 μm), while the cell performance keeps increasing with relatively large particle radius when the AFL grows thicker. Although there exists slight performance drop in condition of non-uniform distribution, the structure reduces ionic-conducting material dosage and fabrication difficulty and it provides another alternative microstructural design which is meaningful to fuel cell optimization.