As lithium-ion batteries are widely used in energy storage and electric vehicle applications, managing the heat generated during rapid discharge remains a key challenge. Although phase change materials (PCMs) are widely used to regulate battery temperature, their performance declines at high discharge rates due to non-uniform melting and thermal saturation. To overcome these limitations, this study presents the use of ultrasonic fields to enhance heat transfer in PCM-based battery cooling systems. Ultrasonic vibrations induce turbulence and improve thermal conductivity, potentially leading to better temperature uniformity. Numerical simulations were performed at discharge rates of 2C, 3C, and 4C for five configurations: a base case with no transducers and cases with 4, 8, 12, and 16 ultrasonic transducers. The results showed that ultrasonic fields significantly improve thermal regulation, particularly at higher discharge rates. At 3C and 4C, the average battery temperature was reduced by up to 7.41 K, and the maximum temperature by up to 21.17 K, compared to the base case. These reductions lower the risk of thermal runaway and enhance battery safety and longevity. Additional analysis of PCM behavior presented in this work confirmed that the acoustic field improved heat distribution and delayed thermal saturation, particularly under severe thermal loads.
