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. •A 2D model for SOFC with MIEC electrolyte is developed.•New 2D expression for electronic current is given.•Characteristics of in-plane electronic current are numerically studied.•The in-plane electronic current density is very small and negligible.