Electrochemomechanics in Mixed Ionic Electronic Conductors and solid oxide cells

This thesis presents a model for coupled electrochemomechanics in Mixed Ionic Electronic Conductors (MIEC). A continuum model is formulated to simulate the transport of ionic defects and the stress distribution in the conductor arising from the chemical expansion associated with the defects. First, a finite element formulation of the model is developed and validated with various analytical solutions and comparisons with experimental results. In the third chapter the coupled model is used along with an iterative scheme to simulate the transport characteristics in solid oxide cells with oxygen surface exchange and results are compared with experimental cell operation. The model is used to study the effect of oxygen surface exchange and the bulk diffusion of defects on the performance of solid oxide cell. In the fourth chapter, the transport of ionic defects is studied under spatially varying oxygen surface exchange in solid oxide cells due to the presence of metal current collector. Various defect transport mechanisms (boundary value problem setups) are proposed and studied to identify and explain the influence of metal current collector on oxygen exchange at the electrode film surface.U of I OnlyAuthor requested U of Illinois access only (OA after 2yrs) in Vireo ETD syste