Comparison of Limiting Descriptions of the Electrical Double Layer Using a Simplified Lithium-Ion Battery Model

This article examines the effects of various hypotheses for the electrical double layer on charge transfer in lithium-ion batteries. We begin by introducing the Poisson Nernst-Planck equations to describe ion transport within a typical liquid solvent and derive an expression for the potential difference in the electroneutral liquid of the separator. We discuss the structure of the electrical double layer and review two distinct hypotheses for interpreting the total potential difference across the electrical double layer. The limiting descriptions lead to different concentration and potential profiles and overpotential during discharge.