Thermal and electrical performance assessments of lithium-ion battery modules for an electric vehicle under actual drive cycles

Abstract

In this paper, both thermal and electrical performance evaluations of a lithium-ion battery pack using real world drive cycles from an electric vehicle (EV) are presented. For the experimental measurements, a data logger is installed in the EV, and the real world drive cycles are collected. The EV has three lithium-ion battery packs consisting of a total of 20 battery modules in series. Each module contains six series×49 parallel IFR 18650 cylindrical valence cells. The reported drive cycles consist of different modes: acceleration, constant speed, and deceleration in both highway and city driving at 2°C, 10°C and 17°C ambient temperatures with all accessories on. Later, the same drive cycles are conducted in an experimental facility where four cylindrical lithium-ion cells are connected in series, and both electrical and thermal performances are evaluated. In addition, the battery model is developed using artificial neural network, which is validated with the real world drive cycles. The validation is carried out in terms of voltage, state of charge (SOC), and temperature profiles for all the collected drive cycles. The present model closely estimates the profiles observed in the experimental data. Moreover, with this study, the mathematical function for the average temperature, SOC, and voltage prediction are developed with weights and bias values.