Abstract
Lithium-ion (Li-ion) batteries are the dominant technology adopted as energy storage in a wide range of applications. Nowadays, Li-ion batteries play a pivotal role in the decarbonization of the world by accelerating clean electrification in the transportation sector. Battery thermal management is a key aspect of Li-ion batteries to ensure safe and efficient performance, as well as a long and reliable lifespan. The active battery thermal management systems (BTMSs) such as air and liquid type thermal management systems are now the most common battery thermal management strategies in electric vehicles (EVs). The hybrid BTMSs combining active methods with passive methods such as phase change materials (PCMs) are promising solutions due to the lower parasitic energy consumption compared to pure active methods. However, the complex structure of hybrid BTMSs requires special attention in the design phase to fulfill the key aspects of a suitable thermal management system, such as lightweight and modularity in design for the further evolution of hybrid BTMSs. Meanwhile, thermal characterization and thermal modeling of batteries are prerequisites for a proper thermal management system design.In this PhD thesis, new methodologies are developed for thermal characterization and thermal management of Li-ion batteries. Firstly, a thermal characterization is conducted to determine the heat capacity and anisotropic thermal conductivity of a prismatic cell through a time-saving and cost- efficient methodology. Afterward, a numerical comparison is made between the air type and liquid type thermal management methods for a 48 V battery module. Focusing on liquid-based BTMS, a novel liquid cooling plate (LCP) is developed, called hybrid LCP, providing a modular solution to integrate liquid cooling with PCM, which is more than 35% lighter than a volumetrically equivalent aluminum LCP. A proof of concept for hybrid LCP is designed and tested by a heating element. Finally, the hybrid LCP is experimentally and numerically investigated for thermal management of the battery module. The proposed hybrid LCP reduces the energy consumption of liquid cooling by 40% compared to a traditional aluminum LCP of comparable size. Additionally, the hybrid LCP is able to prevent the battery from a fast temperature drop during the short EV stop in cold environments.
Date of Award | 24 Feb 2022 |
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Original language | English |
Supervisor | Maitane Berecibar (Promotor), Joeri Van Mierlo (Co-promotor), Wendy Meulebroeck (Jury), Peter Van Den Bossche (Jury), Marijke Huysmans (Jury), Ramon Lopez Erauskin (Jury) & Lu Jin (Jury) |