Full Homogenized Macroscale Model and Pseudo-2-Dimensional Model for Lithium-Ion Battery Dynamics: Comparative Analysis, Experimental Verification and Sensitivity Analysis

Abstract

Control-oriented models based on electrochemistry have conventionally been evaluated and designed from the Doyle-Fuller-Newman (DFN) macroscale model. However, the DFN model is susceptible in predicting battery response under certain operating conditions since it is an approximate representation of pore-scale dynamics. This work shows the limitations of the DFN model in predicting voltage response at high temperatures of cell operation. A full homogenized macroscale (FHM) model, developed in previous research, is shown to overcome these limitations. Results indicate that the predictability of the DFN model deteriorates when trying to predict the voltage response at low state of charge for high temperature of operation under 1 C-rate discharge. The influence of parameters on the model states and output is investigated as a means to address parameter identifiability issues, for which, we formulate and resolve sensitivity functions for the partial differential equations (PDEs) of the FHM model. Results show that parameter identifiability is dependent on the battery state of charge.