A study on a battery pack in a hybrid battery thermal management system integrating with thermoelectric cooling

An inherent limitation of lithium-ion batteries is their restricted use within a specific thermal working range. To address this problem, efficient battery thermal management systems (BTMS) are required to dissipate the heat created by the cells in the battery pack. In order to control the maximum temperature and minimise the temperature difference through the battery pack during a 5C discharging process, this study investigates a phase change material (PCM)-porous battery thermal management system, cooled by thermoelectric coolers (TEC) on its walls. To calculate the heat generation of Li-ion batteries, the equivalent circuit model (ECM) is employed. In this model, a battery is made up of a set of electric elements, including R-C pairs. Different PCM and porous materials are studied to determine the most suitable material for controlling the thermal behaviour of the battery pack. The study reveals that the solidus temperature and latent heat of PCM are the two most crucial factors in PCM selection. A thermoelectric cooler is an instrument that uses electrical energy to transfer heat from one side of the device to the other, depending on the current direction. The study examines the use of a TEC (thermoelectric cooler) under various ambient temperatures and applied voltage differences. The results demonstrate that adjusting the voltage difference between the two TEC heads from 900 to 1500 mV, while the ambient temperature ranges from 303 K to 323 K, allows for achieving a cold plate temperature between 288 K and 308 K. The designed BTMS is tested in various TEC positions, and it is shown that when TECs are used on side walls, the maximum temperature of the battery back can decrease up to 1 K, and better temperature uniformity is observed.