Project title: Immersion Cooling of Lithium Ion Batteries

Supervisors: Dr Gregory Offer, Dr Billy Wu 

The rapid uptake of electric vehicles to reduce CO2 emissions from transportation relies heavily on cheaper energy storage systems. The evolution of lithium-ion batteries to greater power and energy densities requires effective thermal management systems to maximize their performance and increase their cycle life. This project’s aim is to assess if immersion cooling can be a solution to limit detrimental thermal gradients and degradation in cylindrical form factor cells. A tailored test rig was designed and built in-house to compare Li-ion cells immersed in Silicone oils of different viscosities. Cycling the cells, subject to different cooling conditions, helped to compare the temperature profiles and the electrical characteristics, including available capacity and voltage efficiency. The conclusions of this study, coupled with a better understanding of the modes of heat transfer involved, will be valuable to design and improve immersion cooling systems and fluids for battery applications. Better thermal management can lead to increased lifetime, cheaper and lighter batteries with many applications in electric vehicles and renewable energy storage systems.