Mechanical Engineering Faculty Research

Title

Empirical Modeling of Lithium-ion Batteries Based on Electrochemical Impedance Spectroscopy Tests

Document Type

Article

Publication Date

Spring 4-1-2015

Abstract

An empirical model for commercial lithium-ion batteries is developed based on electrochemical impedance spectroscopy (EIS) tests. An equivalent circuit is established according to EIS test observations at various battery states of charge and temperatures. A Laplace transfer time based model is developed based on the circuit which can predict the battery operating output potential difference in battery electric and plug-in hybrid vehicles at various operating conditions. This model demonstrates up to 6% improvement compared to simple resistance and Thevenin models and is suitable for modeling and on-board controller purposes. Results also show that this model can be used to predict the battery internal resistance obtained from hybrid pulse power characterization (HPPC) tests to within 20 percent, making it suitable for low to medium fidelity powertrain design purposes. In total, this simple battery model can be employed as a real-time model in electrified vehicle battery management systems.

Publication Title

Electrochimica Acta

Volume

160

First Page

169

Last Page

177