Development Of Electro-Thermal Model of Lithium-Ion Battery for Plug-In Hybrid Electric Vehicles

Abstract

Lithium-ion batteries play an important role as energy storage systems in automotive applications like hybrid electric vehicles. For an efficient use in such applications, accurate practical electro-thermal circuit and battery models for Lithium-ion cells are proposed in this paper. The main objective of this paper is to present a model, which can be used in the design process of battery packs, starting with the simulation of battery behavior to the point of model-based energy management controllers and cooling strategies. First, an accurate, intuitive, and comprehensive electrical model has been proposed to capture the entire dynamic characteristics of a battery, from nonlinear open-circuit voltage, current, temperature, SOC and storage time-dependent capacity to transient response. Next, the thermal model is used to estimate the heat generation inside the battery. Parameter estimation for both parts of the model is done separately in a two-stage algorithm by fitting the model output to experimental data. Finally, the coupled electro-thermal model is validated using experimental data. The experimental results show the effectiveness of models proposed.