Kinetics of Oxygen Reduction in Aprotic Li-O2 Cells: A Model-Based Study

A comprehensive and general kinetic model is developed for the oxygen reduction reaction in aprotic Li-O-2 cells. The model is based on the competitive uptake of lithium superoxide by the surface and solution. A demonstrative kinetic study is provided to demystify the origin of curvature in Tafel plots as well as the current dependency and aberrant diversity of the nature and morphology of discharge products in these systems. Our results are general and extend to any system where solubilization of superoxide is favored, such as where phase-transfer catalysts play an important role.