Electrothermal and Electrochemical Modeling of Lithium-ion Batteries: 3D Simulation with Experimental Validation

Abstract

This work presents two lithium-ion battery models which are implemented in the multiphysics software package FIRE®, developed by AVL List GmbH: an efficient electrothermal model based on an empirical voltage/current relationship and a physically based, non-isothermal electrochemical model. The models are applied to a 3D simulation of a high energy lithium-ion pouch battery. Both models are adjusted to measured discharge curves for various currents and temperatures. Then their results are compared and a deep insight into the electrodes is given by the electrochemical model. Here, the importance of 3D effects and temperature influence are pointed out – both effects which are often neglected in electrochemical models presented in literature. Finally, both models are compared to voltage and temperature measurements using a realistic, strongly dynamic driving profile. A highly accurate prediction of the experimental data can be achieved with both models.