Evaluating the Thermal Behavior of Miniature Battery Packs Encapsulated with Diverse Potting Materials through Simulation and Experimentation

Electric vehicles represent a pivotal shift in the automotive sector, offering a sustainable alternative to conventional gasoline-powered vehicles. Lithium-ion batteries are extensively chosen as the primary energy source for these vehicles due to their exceptional energy density and extended operational lifespan. Achieving thermal stability during normal battery pack operations is imperative for ensuring both safety and efficiency in electric vehicle technology. Various encapsulants are used to fill the gaps between the cells, providing not only structural rigidity on undulating roads but also enhancing heat transfer capabilities among the cells, thereby maintaining a uniform temperature gradient inside the battery pack. This study explores the effectiveness of three distinct commercially available potting materials—polyurethane (PU) foam, silicone, and silicone-based epoxy—as encapsulants for lithium-ion battery packs. A 3x3 cell configuration is modeled as a battery pack using 18650 NMC cells and simulated to assess the temperature rise and temperature gradient at 0.5C, 1C, and 2C discharge rates. The results are then validated using an experimental setup that mimics the simulated model. The findings provide a comparative analysis of the three potting materials, highlighting their respective advantages and limitations in terms of thermal management. These insights are valuable for optimizing battery pack design, enhancing safety, and improving the longevity and reliability of lithium-ion batteries in various applications.