Effect of the Microstructure of Porous Composite Electrodes on the Electric Power Density of Solid Oxide Fuel Cells

The electric power density generated in co-flow planar solid oxide fuel cells (SOFCs) with porous composite electrodes is predicted using the cell combined micro- macro-model; and the effect of the microstructural variables of the electrodes on the cell power generation is studied. In the combined micro- macro-model, the electrochemical performance of the porous composite electrodes is determined from the micro-model and the distributions of the temperature in solid structure of the cell and the temperature and species partial pressures of the bulk fuel and air streams are determined from the cell macro-model. As a case study, the effect of the microstructural variables of the porous composite electrodes of the Ni-YSZ/YSZ/LSM-YSZ cell operated at the given voltage, fuel utilization ratio, and excess air, on the average power density of the cell is investigated through computer simulation. The results reveal that there is an optimum value for each microstructural variables of the electrodes at which the cell power density is maximized.