A 2D model for solid oxide fuel cell with a mixed ionic and electronic conducting electrolyte

A 2D model for solid oxide fuel cell with a mixed ionic and electronic conducting electrolyte is developed by combining the mass transport model, electrochemical model and charge transport model. A new differential equation of the oxygen partial pressure in the electrolyte is firstly obtained, and an explicit expression of two-dimensional electronic current in the electrolyte is given in the paper. The 2D model results agree the experiment data well. The in-plane electronic current density (parallel to electrolyte) is studied by this model and the results show that the in-plane electronic current density is dependent on the difference between the gradient of local static potential and a new variable ψ (representing oxygen partial pressure) in the electrolyte. By varying the operating voltage, gases inlet velocity and electrolyte thickness in the model respectively, the results show that the magnitude of in-plane electronic current density in the MIEC and its change all are very small and can be neglected in practice.