CFD assessment on thermal management behavior of lithium ion battery by employing phase change material and spiral fins

Boosting the heat transfer capability of phase change materials (PCM) is crucial for their application in the efficient thermal management of power batteries. One of the most prevalent enhancement methods is the use of fins. This paper innovatively presents a spiral fin-PCM design for the thermal management of 26650 batteries. The effects of fin numbers (N) and rotational angles (θ) on thermal performance were numerically scrutinized, with results compared to traditional straight fins. Key findings reveal that natural convection is crucial in battery heat dissipation. As N and θ escalate, the average integral value of the average velocity generally increases. Furthermore, spiral fins reduce the melting time by a maximum of 2 min compared to straight fins. The influence of the fin rotation angle on the transient heat absorption and power of PCM is relatively small, but it has a significant impact on the battery temperature uniformity. Compared to straight fins, coiled fins can reduce the platform temperature in the heat absorption process. Relative to the former, using N = 3 and θ = 180° can maximally reduce battery temperature by 2.7 °C.