Week 10 Thermal Management

Thermal Management Technique for EV Battery Pack

Proper thermal management of EV battery is essential to maintain the adequate and consistent performance of the battery and the vehicle.

Excessive temperature will negatively affect the EV battery and its performance hence it is necessary to monitor the temperature of EV cells for that a battery thermal management is required to prevent temperature extremes and to ensure proper battery performance and achieve the expected life cycle of the battery.

Hence various technique has been developed to ensure proper thermal management of the system. Various cooling agents and methods are in use today as a part of thermal management among these are air cooling, liquid cooling, and direct immersion liquid.

Air Cooling

IT is a low-cost method for EV battery cooling. An air cooling system uses outside air as an intake, an active air cooling system enhances this natural air with the fans and blowers. Air cooling eliminates the need for cooling loops and concern about the liquid linkage into the electronics. The bulky arrangement using liquid and pumps and tubing is avoided. Even though with air cooling and a powerful blower the performance offered by the liquid cooling is not achieved because this led to problems for Even the hot climates more temperature variation in the cells, still air cooling solutions have their roles and variations.

 Thermal Management of Toyota Prius using Air Cooler

Liquid Cooling

The piped liquid cooling system provides better thermal management because its conduction of heat is better than the air-cooled. Tesla car uses liquid glycol as a coolant, the heat is transferred as a refrigerant cycle. The glycol coolant is distributed through the battery pack to cool the cells. The tesla model S cooling system consists of a cooling pipe that winds through the battery pack, there are five individual coolant paths passing through the plate in parallel. The frames with the coolant plates are then stacked longitudinally to make an entire pack.

Chevrolet Volt thermal fins

Liquid Immersion

Liquid Immersion is another type of cooling method this type of cooling method is developed by Xing mobility where the battery cells are immersed in a non-conductive fluid with a high boiling point. The coolant used here is 3M Novec 7200 fluid a nonconductive fluid designed for heat transferred applications. The Xing battery pack has 42 lithium ions modules that are put together to create a large battery pack. The complete battery pack houses 18350 cells in a cased liquid-cooled pack

 The Xing Mobility Battery Pack immersed in Liquid Cooled Module