Mineral Oil Immersion Cooling of Lithium-Ion Batteries: An Experimental Investigation

Effective thermal management of high power density batteries is essential for battery performance, life, and safety. This paper experimentally investigates direct mineral oil jet impingement cooling of the lithium-ion (Li-ion) battery pack. For the first time, experimental results of mineral oil-based cooling of batteries are reported. Both charging and discharging characteristics on temperature uniformity and of a Li-ion pack are considered. Temperature uniformity among cells, as well as within individual cells, is experimentally measured. As a baseline, cooling of the battery pack by free-convective airflow is also reported. Two different jetting configurations: (a) submerged jet and (b) direct-jet impingement are considered. For the highest charge-discharge rates considered (2C charge and 3C discharge), mineral oil nearly maintains uniform skin temperature among the cells (less than 1 °C) as well as within the cell. Based on the results obtained, modular jet oil cooling is an excellent cooling solution of lithium-ion packs applicable to stationary electrical storage and transportation applications.