Three dimensional thermal modeling of lithium-ion battery pack for electric vehicles thermal management

Abstract

Electric vehicles (EVs) are projected as one of the most sustainable selections for future transport. At present stage, one of the key factors restricting EV development is the stability of power battery. During the battery discharge process, significant temperature rise comes along with the uneven temperature distribution of the battery pack, which could reduce the battery longevity as well as the performance. To control the temperature variance and elevation, effective thermal management system has to be applied on the EV battery pack. In this thesis, a 3D thermal model of lithium-ion battery pack is developed to simulate the thermal behaviors of the EV power battery in the working status. A set of battery physical characteristics experiments have been conducted to determine the thermal related parameters of the model. Then the battery pack thermal model is simulated with varying ambient temperatures and discharge rates for the purpose of analyzing the effects of the EV working conditions to the battery pack temperature distribution. Through the battery pack temperature field experiments, the local temperature of the characteristic points is measured, which helps to determine the overall thermal profile and temperature rise rate of the battery pack. Based on the simulation and experimental results, a battery box structure with a new air cooling approach is designed, which is able to improve the heat dissipation efficiency and the temperature uniformity of the battery pack.

Date of Award	2014
Original language	English
Awarding Institution	The Hong Kong University of Science and Technology