Types of thermal regulation systems of the traction battery of an electric vehicle and their analysis

Abstract

The increase in the production of electric vehicles (EVs) largely depends on the reliability and safety of the main components and assemblies. One of the most expensive and dangerous parts of an EV is the power (traction) electric battery. Lithium-ion batteries (Li-ion) have become the most widespread. An important characteristic that affects their safety is performance and service life. These battery indicators depend on the average operating temperature, which must be in the optimal range to prevent a number of negative phenomena. That is why the operation of thermal control systems (TCS) of EV battery packs is important to ensure correct functioning in any environmental and operating conditions.

Lithium-ion (Li-ion) batteries have become the dominant technology for the automotive industry due to some unique features, such as high power, capacity, storage capacity and a large number of possible recharges. However, under deep discharge conditions, a large amount of thermal energy is generated due to redox reactions, and the battery temperature increases excessively and uncontrollably with possible subsequent self-ignition. Therefore, it is necessary to develop such a battery cooling system to prevent damage to the cells due to high operating temperatures. Other problems arise when Li-ion batteries reach temperatures below optimal values, such as the inability to release energy or rapid degradation and capacity reduction. That is why an effective system is needed that can heat the device to reach the optimal temperature range, i.e., a thermal management system (TMS).

Keywords: electric vehicles, thermal management, safety, lithium-ion battery, heat transfer, energy efficiency