Performance Evaluation of Electric Vehicle Thermal Management Systems Using PCM-Coupled Cooling

Abstract

Several factors that influence effective thermal management of electric vehicle (EV) battery systems are crucial in determining how user-friendly, safe and reliable lithium-ion cells are in resisting varying temperatures, which may accelerate ageing, decrease performance and even cause thermal runaway within the sealants of these cells under extreme conditions. The traditional methods of cooling that include air and liquid cooling have been commonly used, though it is typically limited to the ability to ensure uniform temperature distribution and adequate heat dissipation when trying to drive the load in high mode, especially in that of battery pack that is rather small. As a solution to these challenges, the current study proposes research in the area of introductions of phase change material (PCM)-based coupled cooling and traditional thermal management systems as a hybrid strategy, that utilises the big latent heat storage capacity of PCM to absorb short-term heat pressure but decreases the load on active cooling systems. A 3D computational fluid dynamics (CFD) pipe model is created that represents the electrochemical-thermal coupled response of a 48-cell EV battery module that includes physical heat generation profiles, the dynamics of PCM phase transition, and conjugated heat transfer concerning that of solid, liquid, and PCM. The model can be proved by experimental testing of a prototype battery module already set up with PCM-integrated cooling jackets and under different ambient conditions with dynamic driving cycles. Findings indicate that PCM-coupled cooling can cause a substantial drop in peak-cell temperature (12 to 18 percent) and temperature heterogeneity across a module (approximately 25 percent), and leads to a reduction in thermal gradient that is usually the cause of non-uniform cell degradation. In addition, the hybrid system promises a battery cycle life more than 15 percent longer than conventional liquid-only systems due to reduced thermal stress and reduced, though significant, auxiliary energy consumption reduction. These results indicate the potential of PCM-coupled thermal management as more scalable, energy saving, and safety-promoting approach to next generation EV battery systems as a part of enhancing reliability and sustainability of electric mobility.