DRIVE: DiRect contact Immersion cooling of electric VEhicle batteries - a novel approach for improved thermal management and performance

Project Description

The lithium-ion batteries used in electric vehicles (EV) operate optimally only within the narrow temperature range of 25°C-40°C. Outside of this range, power performance degrades, lifespan reduces, and at high temperatures the risk of battery fire and explosion increases significantly. Batteries produce heat when charged or discharged. The rate of heat generation scales with the current supplied or drawn, meaning fast charging/discharging is onerous for the battery thermal management system (BTMS). Traditional air cooling and indirect contact liquid cooling BTMS are inadequate to properly meet current and future targets for battery power densities and have resulted in an unnecessarily large number of batteries in many EV models. We propose to design and experimentally investigate a new BTMS concept, employing direct contact immersion cooling of batteries using dielectric fluids. Using boiling/condensation and dynamic pressure control we can adjust saturation conditions and remove large amounts of heat with relatively small temperature changes. The proposed method can maintain battery temperatures within the 25°C-40°C range for very high rates of charge/discharge, thereby improving the performance of EV, reducing the number of batteries and cost, ultimately making EV more attractive to the consumer, which will help Ireland reach its 2030 emissions goals and beyond.