Finite Element Modeling of the Cycle Characteristics of Li-O₂ Secondary Batteries Considering Surface- and Solution-Route Discharge Reactions

Model-based development is an effectiveapproach in terms of obtainingdesign guidelines for lithium-oxygen secondary batteries (LOBs).In this study, a model simulating the charge/discharge cycle was developedusing the finite element method, which enabled us to investigate thefactors governing the cyclability of LOBs by conducting virtual cycletests. In this modeling, we particularly considered that the dischargecan proceed via two different routes: surface and solution routes.As an example demonstrating the usefulness of the virtual tests basedon the developed model, we evaluated the effects of changes in parametersrelated to oxygen transport properties on the deposition and dissolutionsites of lithium peroxide (Li2O2) generatedin the porous cathode of an LOB via the surface and solution routes,respectively, and hence investigated the effects on the cyclability.The proposed model enables various validations that are extremelydifficult to carry out using an experimental approach.