ABSTRACT Thermal management of lithium‐ion batteries in high‐temperature environments is challenging because the available temperature range for safe operation is significantly limited. Therefore, this study proposes a novel immersion cooling of cylindrical 18650 Li‐ion batteries using a phase‐change material (PCM)‐based slurry. The phase‐change slurry, consisting of Organic Mixture‐42 dispersed in silicone oil, is used as the coolant for the battery module, and its thermal and hydraulic performance is compared with that of a single‐phase coolant. The proposed battery thermal management system design is numerically modeled using the multiscale multidomain framework with the Newman–Tiedemann–Gu–Kim model adopting a single‐phase approximation for the slurry flow. The numerical model is validated against in‐house experimental results by comparing average cell temperature profiles under similar operating conditions. A detailed parametric analysis is performed by varying slurry mass concentrations (0.5%, 1%, 2%, and 4%), flow rates (0.5, 1.0, 1.5, and 2.0 g/s), and ambient temperatures (35°C, 38°C, and 41°C) to assess their impact on thermal performance. The results indicate that the performance gain is maximum at a PCM concentration of 4% and a flow rate of 0.5 g/s, beyond which the benefits are offset by significantly increased pumping power. Incorporating PCM into the single‐phase coolant significantly enhances the heat‐carrying capacity, with a reduction in peak battery temperature rise by 11.8% for 4% PCM‐slurry compared with silicone oil cooling, demonstrating the efficacy of the PCM, especially in high‐temperature environments, where stabilizing battery temperature within a safe operating limit for a longer duration is essential.
Saha et al. (Mon,) studied this question.