Computational Investigations of Charge Transport in Non-Aqueous Li-O 2 Batteries

Abstract

Despite their great promise, there are significant challenges to developing practical Li−air batteries. One is the electrical passivation of the cathode during discharge.[1,2] This occurs because insoluble and insulating Li2O2 produced during discharge builds up as a deposit on the cathode surface and ultimately inhibits charge transfer to the Li2O 2 −electrolyte interface where the electrochemistry occurs. This manifests itself as a “sudden death” (rapid drop in the output potential U) of the discharge at some maximum discharge capacity, Qmax.In this talk, we will discuss the dependence of the maximum discharge capacity Qmaxon the current density, j.[3] We show that a wide range of experiments can be rationalized using a model that accounts for charge transport through tunneling and polarons. We further show that tunneling dominates at the current density of interest.