SAFER LI-ION BATTERIES THROUGH BETTER THERMAL MANAGEMENT

Lithium-ion (Li-ion) batteries are increasingly targeted for electrical energy storage due to their exceptional energy and power density. However, Li-ion batteries operating in the hostile military environments are prone to catastrophic thermally induced failures or reduced lifetime if not maintained within narrow operating windows. There is great interest in advanced thermal management to optimize battery pack performance and enhance safety. In this numerical study, we examine the performance and safety benefits afforded by thermal management systems with effective thermal conductivities beyond the limits of traditional conductive cooling. Thermal runaway simulations based on NREL’s multi-scale multi-domain (MSMD) model illuminate how advanced thermal management can improve power density, while mitigating thermal runaway and cell fratricide potential. More efficient cooling increases the margin of safety, allowing end users to extend the pack operating envelope over an interrelated three parameter space encompassing the maximum permissible discharge rate, ambient operating temperature, and/or thermal runaway pack protection thresholds. Enhanced battery cooling will make Li-ion batteries safer for next generation military vehicles.