Equivalent Circuit Model For Sodium-Ion Batteries With Physical-Based Representations Of Their Non-Linearities

Sodium-ion batteries are a promising technology whose performance can meet the demand of the automotive sector. These batteries require a model that can predict accurately their non-linear behavior with respect to the state of charge. We modeled these cells using a modified equivalent circuit model, with an approach that can separate and study the different electrochemical phenomena involved. The model can accurately provide information on phenomena such as charge transfer and solid-electrolyte interphase. The model can also provide information on the diffusion of sodium within the electrodes or in the electrolyte at a state of charge above 30 percent.