An experimental study on thermal management of lithium ion battery packs using an improved passive method

The performance and life span of the power battery are limited by its operating temperature, hence the battery thermal management (BTM) is a key technology for electric vehicle. In this study, a novel BTM system based on composite phase change materials (C-PCM) with aluminum boxes is developed. The temperature control performance of the system is tested at different discharge rates (1C, 2C) at different ambient temperature (0 °C, 10 °C, 20 °C and 30 °C). The results show that the C-PCM can significantly reduce the average temperature and improve the temperature uniformity of the lithium ion battery pack. Furthermore, the performance of the C-PCM for the thermal control starts to deteriorate after completely melting, therefore an accurate dosage estimation of the C-PCM is a key problem for its application.