Extreme cold-weather battery thermal management for optimal electric vehicle performance

Battery thermal management system (BTMS) may seem a very standard term, but it is the lifeline of an efficient battery pack module in various vehicles and standalone stationary energy storage systems. The majority of the available literature is aimed toward temperature optimization of batteries in hotter climatic conditions. The cold temperature-related effects on battery packs have amplifying implications on the battery cycle life and operational capacity. The electric vehicles operating in cold temperature environment face sudden fluctuations in temperatures across the battery pack module due to large temperature gradient between battery surface and internals, and ambient conditions. This work focuses on addressing the problem related to sudden drop in cell temperatures when battery operations are switched off (cold stop conditions). The phase change materials (PCMs) based passive BTMS system is evaluated in this study. The BTMS with different designs and PCMs are modeled in Multiphysics environment and simulated close to extreme cold temperature environments. The formulated models are then used for comparing commercially available PCMs material for their efficiency and viability. The main parameter evaluated was rate of temperature decrease, it was observed that organic mixture-type PCMs are best suited for cold temperature application.