Current-Dependent Morphologies of Insulating Electrodeposits in Li-O₂ Batteries Controlled by Coupled Ion-Electron Transfer Kinetics

Lithium-oxygen batteries (Li-O₂) present a compelling prospect for the next generation of batteries owing to their exceptionally high theoretical energy density. However, the performance of Li-O₂ batteries remains limited by the formation of insulating oxides covering the gas electrode, leading to low capacity or even unexpected sudden death. Existing mathematical models using Butler-Volmer kinetics exhibit uncertainties and inaccuracies in predicting the voltage responses and the morphological evolution of the insulating oxides. In this study, we incorporate coupled ion-electron transfer theory with a phase-field model to enable consistent predictions of the voltage curves, oxide morphologies, and roles of solvation energy. This study provides a valuable predictive tool for the predictive design of electrolytes and electrodes for batteries forming insulating products.