Understanding Voltage Behavior of Lithium-Ion Batteries in Electric Vehicles Applications

• Published in: Batteries (Basel) Vol. 8; no. 10; p. 130
• Main Authors: Gandoman, Foad H., El-Shahat, Adel, Alaas, Zuhair M., Ali, Ziad M., Berecibar, Maitane, Abdel Aleem, Shady H. E.
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.10.2022
• Subjects: Algorithms; Ambient temperature; Automobiles, Electric; Batteries; battery management system; Case studies; Electric vehicles; Expenditures; Fault detection; High temperature; Life span; Lithium; Lithium cells; Lithium-ion batteries; Open circuit voltage; Power supply; Rechargeable batteries; Reliability (Engineering); Reliability analysis; State of charge; state of health; Belgium
• ISSN: 2313-0105; 2313-0105
• DOI: 10.3390/batteries8100130

Electric vehicle (EV) markets have evolved. In this regard, rechargeable batteries such as lithium-ion (Li-ion) batteries become critical in EV applications. However, the nonlinear features of Li-ion batteries make their performance over their lifetime, reliability, and control more difficult. In this regard, the battery management system (BMS) is crucial for monitoring, handling, and improving the lifespan and reliability of this type of battery from cell to pack levels, particularly in EV applications. Accordingly, the BMS should control and monitor the voltage, current, and temperature of the battery system during the lifespan of the battery. In this article, the BMS definition, state of health (SoH) and state of charge (SoC) methods, and battery fault detection methods were investigated as crucial aspects of the control strategy of Li-ion batteries for assessing and improving the reliability of the system. Moreover, for a clear understanding of the voltage behavior of the battery, the open-circuit voltage (OCV) at three ambient temperatures, 10 °C, 25 °C, and 45 °C, and three different SoC levels, 80%, 50%, and 20%, were investigated. The results obtained showed that altering the ambient temperature impacts the OCV variations of the battery. For instance, by increasing the temperature, the voltage fluctuation at 45 °C at low SoC of 50% and 20% was more significant than in the other conditions. In contrast, the rate of the OCV at different SoC in low and high temperatures was more stable.