Physics based modeling of lithium-ion batteries for electrified vehicle simulations

Official URL: https://risc01.sabanciuniv.edu/record=b2766934_(Table of contents)

Lithium-ion (Li-ion) batteries are one of the most promising energy storage devices because they are portable, lightweight, and have high power density and energy capacity. Hence, modeling such energy storage systems has been an essential and attractive research topic. An electrochemical model can be derived to describe not only the electrical phenomena but also significant micro-scale interactions affecting the characteristics of the battery. Such a model can represent the system behavior with high precision but has a high computational cost as it requires solving tightlycoupled partial differential equations. To mitigate the computational complexity without compromising the fidelity, a simplified electrochemical and thermal model of Li-ion batteries is extensively studied to dissect the battery characteristics. The salient feature of this study is building an electric vehicle simulation framework which can simulate battery performance and life under user defined driving conditions. The framework enables investigating Li-Ion battery performance using physics-based models (PBMs) which are a single particle model (SPM) and SPM with electrolyte dynamics (SPMe) coupled with a capacity degradation mechanism. In addition, a conventional second-order equivalent circuit model (ECM) is built in order to compare its performance with the PBMs.The numerical performance of the models is analyzed by performing several constant current and driving simulations using the simulation framework. The results show that the physics-based models predict battery voltage behaviour more accurately compared to ECM. In addition they provide quantitative information regarding solid electrolyte interface layer formation and battery states such as state of charge and state of health in a computationally-efficient manner.