Flexible phase change material packages for green transportation vehicles

Abstract

Green transportation with net-zero CO2 emissions can only be possible with electric cars that possess reliable long-life batteries. Current hybrid/electric vehicles come with Li-ion batteries that must be kept within certain temperature limits for their safe and economic operation. At higher ambient temperatures, thermal run-aways lead to battery fire risks. Operation temperatures can only be attained by incorporating a cost-effective battery thermal management (BTM) system. This work studies a new, versatile, and high-capacity phase change material (PCM) package for BTM. LiFePO4 battery packs have been tested for different ambient temperatures in typical urban battery charge/discharge cycles. Our findings indicate that such packs with flexible PCM packages operate efficiently. We succeeded in keeping the maximum operation temperatures about 10–15 °C below that of reference battery packs without PCMs. Our economic and environmental assessments conclude that they will become an indispensable smart and clean pathway for real passive BTMs. Flexible PCM packages present a promising alternative to current BTM applications. The energy savings that are achieved with 30% prolonged battery life can decrease CO2 emissions by 1215–1755 kg CO2 depending on the reference fuel for one medium sized vehicle. Green transportation is no longer a myth.